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1

Vitamin B1 and B12 Uptake and Cycling by Plankton Communities in Coastal Ecosystems  

PubMed Central

While vitamin B12 has recently been shown to co-limit the growth of coastal phytoplankton assemblages, the cycling of B-vitamins in coastal ecosystems is poorly understood as planktonic uptake rates of vitamins B1 and B12 have never been quantified in tandem in any aquatic ecosystem. The goal of this study was to establish the relationships between plankton community composition, carbon fixation, and B-vitamin assimilation in two contrasting estuarine systems. We show that, although B-vitamin concentrations were low (pM), vitamin concentrations and uptake rates were higher within a more eutrophic estuary and that vitamin B12 uptake rates were significantly correlated with rates of primary production. Eutrophic sites hosted larger bacterial and picoplankton abundances with larger carbon normalized vitamin uptake rates. Although the >2??m phytoplankton biomass was often dominated by groups with a high incidence of vitamin auxotrophy (dinoflagellates and diatoms), picoplankton (<2??m) were always responsible for the majority of B12-vitamin uptake. Multiple lines of evidence suggest that heterotrophic bacteria were the primary users of vitamins among the picoplankton during this study. Nutrient/vitamin amendment experiments demonstrated that, in the Summer and Fall, vitamin B12 occasionally limited or co-limited the accumulation of phytoplankton biomass together with nitrogen. Combined with prior studies, these findings suggest that picoplankton are the primary producers and users of B-vitamins in some coastal ecosystems and that rapid uptake of B-vitamins by heterotrophic bacteria may sometimes deprive larger phytoplankton of these micronutrients and thus influence phytoplankton species succession. PMID:23091470

Koch, Florian; Hattenrath-Lehmann, Theresa K.; Goleski, Jennifer A.; Sañudo-Wilhelmy, Sergio; Fisher, Nicholas S.; Gobler, Christopher J.

2012-01-01

2

The kidney in vitamin B12 and folate homeostasis: characterization of receptors for tubular uptake of vitamins and carrier proteins.  

PubMed

Over the past 10 years, animal studies have uncovered the molecular mechanisms for the renal tubular recovery of filtered vitamin and vitamin carrier proteins. Relatively few endocytic receptors are responsible for the proximal tubule uptake of a number of different vitamins, preventing urinary losses. In addition to vitamin conservation, tubular uptake by endocytosis is important to vitamin metabolism and homeostasis. The present review focuses on the receptors involved in renal tubular recovery of folate, vitamin B12, and their carrier proteins. The multiligand receptor megalin is important for the uptake and tubular accumulation of vitamin B12. During vitamin load, the kidney accumulates large amounts of free vitamin B12, suggesting a possible storage function. In addition, vitamin B12 is metabolized in the kidney, suggesting a role in vitamin homeostasis. The folate receptor is important for the conservation of folate, mediating endocytosis of the vitamin. Interaction between the structurally closely related, soluble folate-binding protein and megalin suggests that megalin plays an additional role in the uptake of folate bound to filtered folate-binding protein. A third endocytic receptor, the intrinsic factor-B12 receptor cubilin-amnionless complex, is essential to the renal tubular uptake of albumin, a carrier of folate. In conclusion, uptake is mediated by interaction with specific endocytic receptors also involved in the renal uptake of other vitamins and vitamin carriers. Little is known about the mechanisms regulating intracellular transport and release of vitamins, and whereas tubular uptake is a constitutive process, this may be regulated, e.g., by vitamin status. PMID:16760376

Birn, Henrik

2006-07-01

3

Vitamin B12  

MedlinePLUS

... along with other B vitamins, such as niacin, riboflavin, vitamin B6, and magnesium. A prescription form of ... Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, ...

4

Vitamin B12  

MedlinePLUS

... B12 is frequently used in combination with other B vitamins in various vitamin B complex products. ... food and supplements, along with taking folic acid, thiamine, and riboflavin, might help to prevent cervical cancer. ...

5

Vitamin B-12  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin B-12 is a cofactor for 2 enzymes. In the cytoplasm, methionine synthase requires vitamin B-12 in the form of methylcobalamin and catalyzes the conversion of homocysteine to methionine by transfer of a methyl group from methyltetrahydrofolate.This enzyme links the methylation pathway through ...

6

MEASUREMENT OF TOTAL VITAMIN B12 AND HOLOTRANSCOBALAMIN, SINGLY AND IN COBMINATION, IN SCREENING FOR METABOLIC VITAMIN B12 DEFICIENCY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: The standard screening test for vitamin B12 deficiency, measurement of total plasma vitamin B12, has limitations of sensitivity and specificity. Plasma vitamin B12 bound to transcobalamin (holoTC) is the fraction of total vitamin B12 available for tissue uptake and therefore has been pro...

7

Vitamin B12 benefits (image)  

MedlinePLUS

Vitamin B12 is important for metabolism. Metabolism within the body includes the processes of energy generation and use; including nutrition, digestion, absorption, elimination, respiration, circulation, and temperature ...

8

Penicillin and Vitamin B12  

NSDL National Science Digital Library

The WebWare Molecules for July are mentioned in the article "The History of Molecular Structure Determination Viewed through the Nobel Prizes", by Jensen, Palenik, and Suh. One of the recipients discussed, Dorothy Crowfoot Hodgkin, won the Nobel Prize in Chemistry in part for determining the structures of penicillin and vitamin B12.

9

The Role of the Pancreas in Vitamin B12 Absorption: Studies of Vitamin B12 Absorption in Partially Pancreatectomized Rats  

PubMed Central

The effect of partial pancreatectomy (80-90%) on vitamin B12 absorption was studied in the rat. The absorption of 5 ng of 57Co-labeled vitamin B12 was significantly reduced from 70 ±2.5% (mean ±SE) in control and sham-operated rats to 32 ±2.6% in partially pancreatectomized rats. Hog pancreatic extract (0.17 g/kg) improved vitamin B12 absorption from 30.0 to 61.0% in partially pancreatectomized rats but did not alter vitamin B12 absorption in control rats. Chloramphenicol did not enhance vitamin B12 absorption in partially pancreatectomized rats with pancreatic extract-improved vitamin B12 malabsorption. The partially pancreatectomized rats with pancreatic extract-improved vitamin B12 malabsorption were sacrificed and the stomach and small bowel studied in vitro to further define the pathogenesis of the vitamin B12 malabsorption. Rat gastric intrinsic factor stimulated vitamin B12 uptake by intestinal sacs prepared from partially pancreatectomized rats 3.1-fold. Gastric intrinsic factor prepared from partially pancreatectomized rats was as effective in promoting vitamin B12 uptake by rat intestinal sacs as intrinsic factor prepared from control rats. These data indicate that partially pancreatectomized rats develop an abnormality in the absorption of labeled vitamin B12 which can be corrected by pancreatic extract. The vitamin B12 malabsorption is due to neither an alteration in gastric intrinsic factor activity nor an impairment of the intrinsic factor-vitamin B12 receptor in the intestine. It is suggested that in the partially pancreatectomized rats the intrinsic factor-vitamin B12 complex exists in a form which is not available for absorption. PMID:5009110

Toskes, Philip P.; Deren, Julius J.

1972-01-01

10

How common is vitamin B12 deficiency?  

Technology Transfer Automated Retrieval System (TEKTRAN)

In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification.This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers ...

11

THE DIAGNOSIS OF VITAMIN B12 DEFICIENCY IN SHEEP: COMPARISON OF SERUM VITAMIN B12 LEVELS  

E-print Network

THE DIAGNOSIS OF VITAMIN B12 DEFICIENCY IN SHEEP: COMPARISON OF SERUM VITAMIN B12 LEVELS MEASURED Nutritionnelles, INRA, CRZV de Theix, 63122 Ceyrat, France Résumé DIAGNOSTIC DE LA CARENCE EN VITAMINE B12 CHEZ LE MOUTON: COMPARAISON DES TAUX DE VITAMINE B12 S�RIQUE MESUR�S PAR DES TECHNIQUES MICROBIOLOGIQUES ET DE

Paris-Sud XI, Université de

12

Vitamin B12 and Cognitive Function  

PubMed Central

Background More than 2.9 million serum vitamin B12 tests were performed in 2010 in Ontario at a cost of $40 million. Vitamin B12 deficiency has been associated with a few neurocognitive disorders. Objective To determine the clinical utility of B12 testing in patients with suspected dementia or cognitive decline. Methods Three questions were addressed: Is there an association between vitamin B12 deficiency and the onset of dementia or cognitive decline? Does treatment with vitamin B12 supplementation improve cognitive function in patients with dementia or cognitive decline and vitamin B12 deficiency? What is the effectiveness of oral versus parenteral vitamin B12 supplementation in those with confirmed vitamin B12 deficiency? A literature search was performed using MEDLINE, Embase, EBSCO Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the Centre for Reviews and Dissemination database, from January 2002 until August 2012. Results Eighteen studies (7 systematic reviews and 11 observational studies) were identified to address the question of the association between B12 and the onset of dementia. Four systematic reviews were identified to address the question of the treatment of B12 on cognitive function. Finally, 3 randomized controlled trials were identified that compared oral B12 to intramuscular B12. Conclusions Based on very low quality evidence, there does appear to be an association between elevated plasma homocysteine levels (a by-product of B vitamins) and the onset of dementia. Based on moderate quality evidence, but with less than optimal duration of follow-up, treatment with B12 supplementation does not appreciably change cognitive function. Based on low to moderate quality of evidence, treatment with vitamin B12 and folate in patients with mild cognitive impairment seems to slow the rate of brain atrophy. Based on moderate quality evidence, oral vitamin B12 is as effective as parenteral vitamin B12 in patients with confirmed B12 deficiency. Plain Language Summary Low levels of vitamin B12 have been associated with neurocognitive disorders. This evidence-based analysis assessed the usefulness of serum vitamin B12 testing as it relates to brain function. This review found very low quality evidence that suggests a connection between high plasma homocysteine levels (a by-product of B vitamin metabolism in the body) and the onset of dementia. Moderate quality of evidence indicates treatment with vitamin B12 does not improve brain function. Moderate quality of evidence also indicates treatment using oral vitamin B12 supplements is as effective as injections of vitamin B12. PMID:24379897

2013-01-01

13

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically  

E-print Network

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically to assimilate dietary vitamin B12. Assaying and understanding absorption and uptake of B12 is important because and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin

California at Davis, University of

14

Assay for vitamin B12 absorption and method of making labeled vitamin B12  

DOEpatents

The invention provides methods for labeling vitamin B12 with .sup.14C, .sup.13C, tritium, and deuterium. When radioisotopes are used, the invention provides for methods of labeling B12 with high specific activity. The invention also provides labeled vitamin B12 compositions made in accordance with the invention.

Anderson, Peter J. (Davis, CA); Dueker, Stephen (Davis, CA); Miller, Joshua (Davis, CA); Green, Ralph (Elmacero, CA); Roth, John (Davis, CA); Carkeet, Colleen (Silver Spring, MD); Buchholz,; Bruce A. (Orinda, CA)

2012-06-19

15

Molecular Structure of Vitamin B12  

NSDL National Science Digital Library

Vitamin B12 (cyanocobalamin) has many uses as a nutritional supplement in both humans and livestock. It is used in humans to treat pernicious anemia, hepatitis, cirrhosis of the liver, and to help maintain the body's metabolism. In its long-effect form (hydroxocobalamin), vitamin B12 is used to treat anemia, growth impediment, improvement in the function of the heart, liver, kidneys and nerves, and general strengthening of the body. In livestock, it is used to improve feed production.

2002-08-13

16

CARDIOVASCULAR LESIONS IN COBALT-VITAMIN B12 DEFICIENT SHEEP  

E-print Network

CARDIOVASCULAR LESIONS IN COBALT-VITAMIN B12 DEFICIENT SHEEP R. MOHAMMED M. LAMAND Laboratoire des to 0.10 mg/kg of dry matter is known to induce vitamin B 12 deficiency in sheep (Marston, 1970; Smith (Underwood, 1977). Adult sheep are considered vitamin B 12 deficient when serum vitamin B12 levels attains

Paris-Sud XI, Université de

17

Vitamin B12-induced acneiform eruption.  

PubMed

Drug-induced acne is a specific subset of acne that usually has some specific features, namely monomorphic pattern, unusual location of the lesions beyond the seborrheic areas, uncommon age of onset, a resistance to conventional acne treatment. Several drugs have been associated with the development of eruptions that may simulate acne vulgaris. However, so far, there are a few cases of vitamin B12-induced acne. We report a case of acneiform eruption induced by vitamin B12 injection in a 37-year-old female patient. PMID:23815241

Balta, Ilknur; Ozuguz, Pinar

2014-06-01

18

Vitamin B12 derivatives for orthogonal functionalization.  

PubMed

The synthesis of vitamin B12 derivatives for selective orthogonal conjugation at both the Co center and 5'-OH is reported. Newly developed, reduction-free, direct alkynylation of vitamin B12 at the central cobalt ion proved to be versatile, with the formed acetylides, unlike other metalloorganic derivatives, showing remarkable heat and light stability, thus making them promising candidates as a drug carrier. Subsequently, high-yielding functionalization can be achieved via a sequence of selective [1,3] dipolar azide-alkyne cycloadditions (AACs) or carbamate formation followed by AAC. PMID:25046078

Chromi?ski, Miko?aj; Lewalska, Agnieszka; Karczewski, Maksymilian; Gryko, Dorota

2014-08-15

19

The discovery of vitamin B(12).  

PubMed

The discovery of vitamin B(12), the elucidation of its role in metabolism, and the effects and treatment of its deficiency occurred in distinct phases over more than 100 years, and it was the subject of two separate Nobel Prizes. The valuable contribution of clinical reports and studies of patients with pernicious anemia throughout the 19th century resulted in enough clinical definition to allow Minot and Murphy to put together the first hallmark study on treatment of the condition, leading them to a Nobel Prize. These researchers were not the first to suggest that an inadequacy of nutrients was the cause of pernicious anemia, but their particular input was a carefully designed intervention in well-characterized pernicious anemia patients, of a special diet containing large amounts of liver. They found consistent improvement in the clinical and blood status of all subjects, most of whom remained on remission indefinitely. After the successful intervention studies, the next advance was made by Castle who discovered that a gastric component, which he called intrinsic factor, was missing in pernicious anemia. Many years later, intrinsic factor was found to be a glycoprotein that formed a complex with vitamin B(12), promoting its absorption through ileal receptors. The vitamin was isolated by two groups simultaneously and was crystallized and characterized in the laboratory of Dorothy Hodgkin, contributing to her Nobel Prize in 1964. Subsequently, the various biochemical roles of vitamin B(12) were elucidated, including its important interaction with folate and their common link with megaloblastic anemia. Many of the early clinical studies recognized that vitamin B(12) deficiency also caused a severe neuropathy leading to paralysis and death, while post mortem analysis demonstrated spinal cord demyelination. Vitamin B(12) is still the subject of intense research and, in particular, its role in preventing these irreversible neurological lesions remains unclear. PMID:23183296

Scott, John M; Molloy, Anne M

2012-01-01

20

21 CFR 184.1945 - Vitamin B 12..  

Code of Federal Regulations, 2013 CFR

... 3 2013-04-01 2013-04-01 false Vitamin B 12.. 184.1945 Section 184.1945 Food...Specific Substances Affirmed as GRAS § 184.1945 Vitamin B 12 .. (a) Vitamin B12 , also known as cyanocobalamin (C63...

2013-04-01

21

21 CFR 184.1945 - Vitamin B12.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-04-01 2009-04-01 true Vitamin B12. 184.1945 Section 184.1945 Food and...Specific Substances Affirmed as GRAS § 184.1945 Vitamin B12. (a) Vitamin B12 , also known as cyanocobalamin (C63...

2010-04-01

22

21 CFR 862.1810 - Vitamin B12 test system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Vitamin B12 test system. 862.1810 Section...Chemistry Test Systems § 862.1810 Vitamin B12 test system. (a) Identification. A vitamin B12 test system is a device intended...

2010-04-01

23

21 CFR 862.1810 - Vitamin B12 test system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Vitamin B12 test system. 862.1810 Section...Chemistry Test Systems § 862.1810 Vitamin B12 test system. (a) Identification. A vitamin B12 test system is a device intended...

2012-04-01

24

Vitamin B12 replacement. To B12 or not to B12?  

PubMed Central

OBJECTIVE: To review the evidence for an expanded approach to identifying and treating patients with cobalamin deficiency. Controversy surrounds this issue. Some authors claim that seven times more patients are treated than have true deficiency. New diagnostic tests and identification of patients who have neurologic consequences without hematologic abnormalities suggest that some of these patients have a vitamin B12 tissue deficiency. QUALITY OF EVIDENCE: A MEDLINE search of English-language literature from 1990 to 1995 revealed retrospective and prospective studies of diagnostic tests; prospective surveys; a cohort study; and retrospective and prospective case series, some with control groups. No double-blind controlled trials of treatment were found. MAIN FINDINGS: Some patients with neuropsychiatric abnormalities develop a cobalamin tissue deficiency that can be detected by elevated serum homocysteine and methylmalonic acid levels despite normal serum vitamin B12 levels without macrocytic anemia. Serum cobalamin testing is neither sensitive nor specific in the low normal range for cobalamin deficiency. Treatment recommendations vary because no controlled trials support any recommendations. Oral cobalamin is an underused alternative to parenteral treatment. CONCLUSION: Until the newer diagnostic tests become widely available, family physicians must continue to take a traditional approach to diagnosing vitamin B12 deficiency. There is, however, support for a clinical trial of treatment in patients with neuropsychiatric symptoms. PMID:9154363

Delva, M. D.

1997-01-01

25

Radiolysis of cyanocobalamin (vitamin B 12)  

NASA Astrophysics Data System (ADS)

Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B 12) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1×10 -5 M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1×10 -3. A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%.

Juanchi, X.; Albarran, G.; Negron-Mendoza, A.

2000-03-01

26

Vitamin B12-Containing Plant Food Sources for Vegetarians  

PubMed Central

The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori) is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups. PMID:24803097

Watanabe, Fumio; Yabuta, Yukinori; Bito, Tomohiro; Teng, Fei

2014-01-01

27

Modern Society and Prospects of Low Vitamin B12 Intake  

Microsoft Academic Search

Background: Vitamin B12 deficiency can occur in individuals with dietary patterns that exclude animal foods and patients who are unable to absorb vitamin B12 in food. Material and Method: Our clinic serves a high-income population living in Southern Israel. We hypothesize that a tendency to decrease of level of vitamin B12 in our population is caused by a premeditated decrease

Ilia Volkov; Inna Rudoy; Mochamed Machagna; Inna Glezer; Uri Ganel; Anna Orenshtein

2007-01-01

28

Vegan diet, subnormal vitamin B-12 status and cardiovascular health.  

PubMed

Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases. PMID:25195560

Woo, Kam S; Kwok, Timothy C Y; Celermajer, David S

2014-08-01

29

Genome-wide Association Study of Vitamin B6, Vitamin B12, Folate,  

E-print Network

REPORT Genome-wide Association Study of Vitamin B6, Vitamin B12, Folate, and Homocysteine Blood Schlessinger,12 Manuela Uda,6 and Luigi Ferrucci2 The B vitamins are components of one-carbon metabolism (OCM circulating vitamin B6, vitamin B12, folate and homocysteine, a genome-wide association analysis was conducted

Abecasis, Goncalo

30

Vitamin B12 content in raw and cooked beef.  

PubMed

The aim of this work was to evaluate the vitamin B12 content and profile of cobalamin bioactive forms in raw and cooked beef. The study showed that vitamin B12 distribution is unequal among beef muscles. The content of this nutrient ranges from 0.7 to 1.5 ?g/100 g of tissue. In beef, three biologically active forms of vitamin B12 were determined, i.e.: methylcobalamin, adenosylcobalamin and hydroxycobalamin; the dominating form of vitamin B12 was adenosylcobalamin (68% of total cobalamins). The process of roasting and grilling had little effect on the vitamin B12 content in the final product as compared to the raw meat. The fried product was characterised by about a 32% lower content of cobalamins than in raw meat. PMID:24361556

Czerwonka, Ma?gorzata; Szterk, Arkadiusz; Waszkiewicz-Robak, Bo?ena

2014-03-01

31

Considering the case for vitamin B12 fortification of flour  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reasons to fortify flour with vitamin B12 are considered, which include the high prevalence of depletion and deficiency of this vitamin that occurs in persons of all ages in resource-poor countries and in elderly in wealthier countries, as well as the adverse functional consequences of poor vitamin ...

32

Utility of measuring vitamin B 12 and its active fraction, holotranscobalamin, in neurological vitamin B 12 deficiency syndromes  

Microsoft Academic Search

Vitamin B12 (VitB12, cobalamin) deficiency has been associated with various neuropsychiatric conditions, such as peripheral neuropathy, subacute\\u000a combined degeneration, affective disorders, and cognitive impairment. Current assays analyze vitamin B12, of which only a small percentage is metabolically active. Measurement of its active fraction, holotranscobalamin, might\\u000a be of greater relevance, but data in populations with neuropsychiatric populations are lacking. In this

Wiebke Schrempf; Marco Eulitz; Volker Neumeister; Gabriele Siegert; Rainer Koch; Heinz Reichmann; Alexander Storch

2011-01-01

33

Vitamin B12 deficiency—need for a new guideline  

Microsoft Academic Search

OBJECTIVES: Many patients with vitamin B12 deficiency do not have anemia or macrocytosis, but the prevalence of B12 deficiency in patients without macrocytosis is not known.METHODS: We investigated the prevalence of B12 deficiency among patients with normocytosis and microcytosis and recommended a screening strategy. All patients (n = 3714) with serum B12 measured at the Prince of Wales Hospital in

Chung Hin Chui; Fung Yi Lau; Raymond Wong; Oi Yan Soo; Chuk Kwan Lam; Pui Wai Lee; Ho Kei Leung; Chiu Kui So; Wai Chiu Tsoi; Nelson Tang; Wai Kei Lam; Gregory Cheng

2001-01-01

34

INTAKES OF ADDED VITAMINS - FOLATE, VITAMIN B12, AND VITAMIN E  

Technology Transfer Automated Retrieval System (TEKTRAN)

As foods in the marketplace continue to be fortified with nutrients, it necessitates separation of added forms of some vitamins from natural forms. The USDA Food and Nutrient Database for Dietary Studies (FNDDS) now includes added forms of folate, vitamin B12, and vitamin E. Folic acid, the added fo...

35

Investigation of a vitamin B12 conjugate as a PET imaging probe.  

PubMed

Nutrient demand is a fundamental characteristic of rapidly proliferating cells. Vitamin B12 is vital for cell proliferation; thus neoplastic cells have an increased demand for this essential nutrient. In this study we exploited the vitamin B12 uptake pathway to probe the nutritional demand of proliferating cells with a radiolabeled B12 derivative in various preclinical tumor models. We describe the synthesis and biological evaluations of copper-64-labeled B12 -ethylenediamine-benzyl-1,4,7-triazacyclononane-N,N',N''-triacetic acid (B12 -en-Bn-NOTA-(64) Cu), the first example of a B12 derivative for positron emission tomography (PET) imaging. Small-animal imaging and pharmacological evaluation show high tumor uptake ranging from 2.20 to 4.84%?ID g(-1) at 6 h post-administration. Competition studies with excess native B12 resulted in a 95% decrease in tumor accumulation, indicating the specificity of this radiopharmaceutical for B12 endocytotic transport proteins. These results show that a vitamin B12 PET radiopharmaceutical has potential utility for non-invasive imaging of enhanced nutrient demand in proliferating cells. PMID:24753453

Ikotun, Oluwatayo F; Marquez, Bernadette V; Fazen, Christopher H; Kahkoska, Anna R; Doyle, Robert P; Lapi, Suzanne E

2014-06-01

36

21 CFR 862.1810 - Vitamin B 12 test system.  

Code of Federal Regulations, 2013 CFR

...measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of anemias of gastrointestinal malabsorption. (b) Classification. Class...

2013-04-01

37

21 CFR 862.1810 - Vitamin B 12 test system.  

Code of Federal Regulations, 2014 CFR

...measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of anemias of gastrointestinal malabsorption. (b) Classification. Class...

2014-04-01

38

21 CFR 862.1810 - Vitamin B12 test system.  

Code of Federal Regulations, 2011 CFR

...DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1810 Vitamin B12 test system. (a) Identification. A...

2011-04-01

39

THE POTENTIAL COCARCINOGENIC EFFECT OF VITAMIN B12 DEFICIENCY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since vitamin B12 serves as a cofactor in the synthesis of methyl precursors for biological methylation and enables methylfolate to be recycled for nucleotide synthesis, B12 deficiency has been known to induce hyperhomocysteinemia and inadequate DNA synthesis along with 'methylfolate trap'. Even tho...

40

Unraveling vitamin B12-responsive gene regulation in algae.  

PubMed

Photosynthetic microalgae play a vital role in primary productivity and biogeochemical cycling in both marine and freshwater systems across the globe. However, the growth of these cosmopolitan organisms depends on the bioavailability of nutrients such as vitamins. Approximately one-half of all microalgal species requires vitamin B12 as a growth supplement. The major determinant of algal B12 requirements is defined by the isoform of methionine synthase possessed by an alga, such that the presence of the B12-independent methionine synthase (METE) enables growth without this vitamin. Moreover, the widespread but phylogenetically unrelated distribution of B12 auxotrophy across the algal lineages suggests that the METE gene has been lost multiple times in evolution. Given that METE expression is repressed by the presence of B12, prolonged repression by a reliable source of the vitamin could lead to the accumulation of mutations and eventually gene loss. Here, we probe METE gene regulation by B12 and methionine/folate cycle metabolites in both marine and freshwater microalgal species. In addition, we identify a B12-responsive element of Chlamydomonas reinhardtii METE using a reporter gene approach. We show that complete repression of the reporter occurs via a region spanning -574 to -90 bp upstream of the METE start codon. A proteomics study reveals that two other genes (S-Adenosylhomocysteine hydrolase and Serine hydroxymethyltransferase2) involved in the methionine-folate cycle are also repressed by B12 in C. reinhardtii. The strong repressible nature and high sensitivity of the B12-responsive element has promising biotechnological applications as a cost-effective regulatory gene expression tool. PMID:24627342

Helliwell, Katherine E; Scaife, Mark A; Sasso, Severin; Araujo, Ana Paula Ulian; Purton, Saul; Smith, Alison G

2014-05-01

41

High-dose compared with low-dose vitamin B-12 supplement use is not associated with higher vitamin B-12 status in children, adolescents, and older adults.  

PubMed

Over-the-counter vitamin supplements on the Canadian market are permitted to contain a daily vitamin B-12 dose of up to 1000 ?g. Our objective was to determine the association between total daily vitamin B-12 supplement dose and markers of vitamin B-12 status in Canadians. Blood collected from a nationally representative sample aged 6-79 y (n = ?5600) in the Canadian Health Measures Survey (2007-2009) was analyzed for serum vitamin B-12 and plasma total homocysteine (tHcy). Total daily intake of vitamin B-12 from single and multivitamin supplements was calculated. Individuals that indicated proton pump inhibitor or vitamin B-12 injection treatment were excluded from the supplement dose and tHcy analyses; folate-deficient individuals were also excluded from the tHcy analysis. Twenty-three percent of children, 12.3% of adolescents, and 25.5% of adults consumed a vitamin B-12-containing supplement. Supplement users had 33% higher serum vitamin B-12 and 4.2% higher prevalence of adequacy than did non-supplement users. Children and adolescents consuming >10 ?g/d supplemental vitamin B-12 did not demonstrate higher serum vitamin B-12, higher prevalence of serum vitamin B-12 adequacy, or lower tHcy than did those consuming >0-10 ?g/d. The association between serum vitamin B-12 reached a plateau at doses of >25 and >10-25 ?g/d in adults aged 46-59 and 60-79 y, respectively. The prevalences of serum vitamin B-12 adequacy and normal tHcy, and tHcy did not differ by vitamin B-12 supplement dose in adults >45 y. In this cross-sectional study, vitamin B-12 supplement doses >10-25 ?g/d were not associated with higher vitamin B-12 status in children, adolescents, or older adults compared with lower doses. PMID:24699807

MacFarlane, Amanda J; Shi, Yipu; Greene-Finestone, Linda S

2014-06-01

42

A vitamin B-12 supplement of 500 ?g/d for eight weeks does not normalize urinary methylmalonic acid or other biomarkers of vitamin B-12 status in elderly people with moderately poor vitamin B-12 status.  

PubMed

Plasma vitamin B-12 is the most commonly used biomarker of vitamin B-12 status, but the predictive value for low vitamin B-12 status is poor. The urinary methylmalonic acid (uMMA) concentration has potential as a functional biomarker of vitamin B-12 status, but the response to supplemental vitamin B-12 is uncertain. A study was conducted to investigate the responsiveness of uMMA to supplemental vitamin B-12 in comparison with other biomarkers of vitamin B-12 status [plasma vitamin B-12, serum holotranscobalamin (holoTC), plasma MMA] in elderly people with moderately poor vitamin B-12 status. A double-blind, placebo-controlled, randomized 8-wk intervention study was carried out using vitamin B-12 supplements (500 ?g/d, 100 ?g/d, and 10 ?g/d cyanocobalamin) in 100 elderly people with a combined plasma vitamin B-12 <250 pmol/L and uMMA ratio (?mol MMA/mmol creatinine) >1.5. All biomarkers had a dose response to supplemental vitamin B-12. Improvements in plasma vitamin B-12 and serum holoTC were achieved at cobalamin supplements of 10 ?g/d, but even 500 ?g/d for 8 wk did not normalize plasma vitamin B-12 in 8% and serum holoTC in 12% of people. The response in uMMA was comparable with plasma MMA; 15-25% of people still showed evidence of metabolic deficiency after 500 ?g/d cobalamin for 8 wk. There was a differential response in urinary and plasma MMA according to smoking behavior; the response was enhanced in ex-smokers compared with never-smokers. uMMA offers an alternative marker of metabolic vitamin-B12 status, obviating the need for blood sampling. PMID:23236022

Hill, Marilyn H; Flatley, Janet E; Barker, Margo E; Garner, Clare M; Manning, Nigel J; Olpin, Simon E; Moat, Stuart J; Russell, Jean; Powers, Hilary J

2013-02-01

43

An update of vitamin B12 metabolism and deficiency states.  

PubMed

Vitamin B12 deficiency may be underestimated in the general population. High-risk groups for the deficiency syndrome include the elderly, patients taking ulcer medications over long periods, patients with acquired immunodeficiency syndrome, vegetarians, patients who have undergone stomach resection or small bowel resection, or both, and patients with dementia. The vitamin B12 deficiency syndrome is characterized by five stages, the fifth of which results in irreversible neuropsychiatric manifestations. Although the deficiency is easily treated, diagnosis is somewhat complicated by the shortcomings of the various tests. Current state-of-the-art testing uses serum cobalamin levels as a screening test and serum or urine homocysteine and methylmalonic acid determinations as confirmatory tests. Vitamin B12 deficiency is treatable with monthly injections, large doses of daily oral supplement tablets, or an intranasal gel, which is far better absorbed than comparable oral supplements. PMID:7500070

Swain, R

1995-12-01

44

Iron Limitation of a Springtime Bacterial and Phytoplankton Community in the Ross Sea: Implications for Vitamin B12 Nutrition  

PubMed Central

The Ross Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B12 colimited. In this study, we examined trace metal limitation of biological activity in the Ross Sea in the austral spring and considered possible implications for vitamin B12 nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B12, cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season Ross Sea phytoplankton community. The lack of B12 limitation in this location is consistent with previous Ross Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B12 was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B12 uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B12, but also as a significant sink, and that iron additions enhanced B12 uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95?pM B12. A rapid B12 uptake rate was observed after 13?min, which then decreased to a slower constant uptake rate over the next 52?h. Results from this study highlight the importance of iron availability in limiting early season Ross Sea phytoplankton growth and suggest that rates of vitamin B12 production and consumption may be impacted by iron availability. PMID:21886638

Bertrand, Erin M.; Saito, Mak A.; Lee, Peter A.; Dunbar, Robert B.; Sedwick, Peter N.; DiTullio, Giacomo R.

2011-01-01

45

Iron limitation of a springtime bacterial and phytoplankton community in the ross sea: implications for vitamin b(12) nutrition.  

PubMed

The Ross Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B(12) colimited. In this study, we examined trace metal limitation of biological activity in the Ross Sea in the austral spring and considered possible implications for vitamin B(12) nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B(12), cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season Ross Sea phytoplankton community. The lack of B(12) limitation in this location is consistent with previous Ross Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B(12) was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B(12) uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B(12), but also as a significant sink, and that iron additions enhanced B(12) uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95?pM B(12). A rapid B(12) uptake rate was observed after 13?min, which then decreased to a slower constant uptake rate over the next 52?h. Results from this study highlight the importance of iron availability in limiting early season Ross Sea phytoplankton growth and suggest that rates of vitamin B(12) production and consumption may be impacted by iron availability. PMID:21886638

Bertrand, Erin M; Saito, Mak A; Lee, Peter A; Dunbar, Robert B; Sedwick, Peter N; Ditullio, Giacomo R

2011-01-01

46

Plasma folate, vitamin B-6, vitamin B-12, and risk of breast cancer in women  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: B vitamins such as folate, vitamin B-6, and vitamin B-12 are coenzymes that are important for DNA integrity and stability. Deficiency in these B vitamins may promote tumor carcinogenesis. Objective: We prospectively evaluated plasma concentrations of folate, pyridoxal 5'-phosphate (PLP; ...

47

Involuntary movements misdiagnosed as seizure during vitamin B12 treatment.  

PubMed

Seizures and epilepsy are a common problem in childhood. Nonepileptic paroxysmal events are conditions that can mimic seizure and frequent in early childhood. Nonepileptic paroxysmal events can be due to physiological or exaggerated physiological responses, parasomnias, movement disorders, behavioral or psychiatric disturbances, or to hemodynamic, respiratory, or gastrointestinal dysfunction. Vitamin B12 deficiency is a treatable cause of failure to thrive and developmental regression, involuntary movements, and anemia. Involuntary movements rarely may appear a few days after the initiation of vitamin B12 treatments and might be misdiagnosed as seizure. Here, we report 2 patients who presented with involuntary movements with his video image. PMID:24196096

Carman, Kursat Bora; Belgemen, Tugba; Yis, Uluc

2013-11-01

48

The effect of antiepileptic drugs on vitamin B12 metabolism.  

PubMed

The effects of antiepileptic drugs (AED) on the serum concentration of vitamin B12, folic acid and homocysteine (HMC), and erythrocyte folic acid levels were determined in 45 epileptic patients (30 women, 15 men; mean age 31.7 years) and 23 healthy volunteers (control group; 18 women, five men; mean age 33.4 years). All patients were either on carbamazepine (CMZ), oxcarbazepine (OXZ), or valporate (VP) monotherapy. Serum vitamin B12 levels were low in 17.8% of patients and 8.7% of the controls (P = 0.299). Serum homocysteine levels were high in 17.8% of the patients (P = 0.008). Fifty percent of the patients who had hyperhomocysteinemia, and 75% of the patients who had low serum vitamin B12 level were on CMZ monotherapy. Peripheral blood smears showed hypersegmented neutrophils and macrocytosis in 13.3%, hypochromia and microcytosis in 26.7%, acanthocytes in 2.2%, and thrombocytosis in 2.2% of all patients. The control group had normal peripheral blood smears, except in four cases that showed hypocromia and microcytosis. Long-term administration of AED may cause elevation of homocysteine and development of subnormal serum vitamin B12 levels. Peripheral blood smear abnormalities were frequently seen in patients receiving antiepileptic treatment (P = 0.022), particularly in patients on CMZ monotherapy (P = 0.281). However, homocysteine, vitamin B12, folic acid levels and peripheral blood smear findings did not correlate with the drugs used (P = 0.665, 0.336, 0.249 for CMZ, OXZ, VP, respectively). PMID:18190464

Aslan, K; Bozdemir, H; Unsal, C; Güvenc, B

2008-02-01

49

Vitamin B12 deficiency in relation to functional disabilities.  

PubMed

This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12) deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999-2002 National Health and Nutrition Examination Surveys (NHANES) were categorized in relation to three previously used definitions of B12 deficiency: (1) serum B12 < 148 pmol/L; (2) serum B12 < 200 pmol/L and serum homocysteine > 20 ?mol/L; and (3) serum B12 < 258 pmol/L or serum methylmalonic acid > 0.21 ?mol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living) were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds) (95% confidence intervals), p value: 9.70 (2.24, 42.07), 0.004 and report greater total disability, 19.61 (6.22, 61.86) 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid). Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete. PMID:24225845

Oberlin, Breanna S; Tangney, Christy C; Gustashaw, Kristin A R; Rasmussen, Heather E

2013-11-01

50

Folate–vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous reports on pernicious anemia treatment suggested that high folic acid intake adversely influences the natural history of vitamin B-12 deficiency, which affects many elderly individuals. However, experimental investigation of this hypothesis is unethical, and the few existing observational d...

51

Effect of combined folic acid, Vitamin B6, and Vitamin B12 on colorectal adenoma  

Technology Transfer Automated Retrieval System (TEKTRAN)

Folic acid, vitamin B(6), and vitamin B(12) act in concert in the one-carbon metabolism and may protect against colorectal neoplasia. We examined the effect of combined B-vitamin treatment on the occurrence of colorectal adenoma. The Women's Antioxidant and Folic Acid Cardiovascular Study was a rand...

52

Hooked to vitamin B12 since 1955: a historical perspective.  

PubMed

In our pioneering work in 1956, two binders of vitamin B12 (B12) alias cobalamin (Cbl) were identified in gastric juice, S with slow electrophoretic mobility, a 70 kD protein with intrinsic factor (IF) activity and another rapid (R), not IF active but probable digestion product. Numerous sources contained a protein immunologically identical to R (haptocorrin, Hc). Another IF-active component (I) was found. Isoelectric focusing showed that S, I and R were assemblies of "isoproteins" with different pI's due to varying glycosidation. Isolation of S, I and R in microquantities was achieved in 1962 using a series of ion exchange chromatographies and gel filtration. Ponderable products were obtained in 1965-1966. The B12-IF complex was a dimer, contained 13% carbohydrate and showed a different absorption spectrum than B12. Using the Schilling test, B12 absorption was shown to require Ca(++), bound in vitro to the ileal receptor and IF, but most of Ca(++) could be removed with sialidase. The receptor-substrate complex contained Ca(++) and carbohydrate. The purified receptor was shown to contain two main subunits. The Imerslund-Gräsbeck syndrome was discovered 1958-1960; it is caused by mutations in either of two genes, cubilin or amnionless, which form the multiligand receptor cubam. Testicular biopsies during and after B12-treated deficiency showed remarkable improvement after therapy. Studies of the turnover of radioactive B12 revealed biliary and fecal excretion, enterohepatic circulation and allowed calculation of biological half-life and daily need. The B12 coenzymes largely behaved like B12. To study whether radiocobalt in B12 was representative of the rest of the B12 molecule, (32)P and (57)Co labeled hydroxocobalamins were biosynthesized and shown to behave identically when given simultaneously to rats. The complex metabolism of B12 explains the pathogenesis of B12 deficiencies. Some of its mechanisms are not restricted to B12, e.g. the endocytosis of B12-IF also applies to other macromolecules. PMID:23274132

Gräsbeck, Ralph

2013-05-01

53

Decreased Vitamin B12 Levels in Children with Nocturnal Enuresis  

PubMed Central

Objectives. Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In the present study, vitamin B12 and folate levels were measured in children with nocturnal enuresis and compared with those in healthy control group children to investigate whether there was any relation with enuresis and neurogenic maturation as a first time in the literature. Methods. In this cross-sectional study, we included thirty children (16 girls, 14 boys) who had presented with primary nocturnal enuresis (PNE) complaints in the study group and 31 children (13 girls, 18 boys) in the control group. Body weight and height measurements were obtained and complete blood counts and vitamin B12 and folate levels were measured in all children. Results. No difference was found in age, height, and weight between study and control groups. Also the mean levels of the hemoglobin, hematocrit, and mean corpuscular volume (MCV) were not different between the two groups. Significantly lower mean vitamin B12 and folate levels were found in the enuresis group compared with the control group. Conclusions. Further studies are needed to clarify B12 and folate deficiency in larger series so that these tests can be included in routine investigations of enuretic children. PMID:22523715

Altunoluk, Bülent; Davutoglu, Mehmet; Garipardic, Mesut; Bakan, Vedat

2012-01-01

54

Antiparasitic Effect of Vitamin B12 on Trypanosoma cruzi.  

PubMed

A nutritional characteristic of trypanosomatid protozoa is that they need a heme compound as a growth factor. Because of the cytotoxic activity of heme and its structural similarity to cobalamins, we have investigated the in vitro and in vivo effect of vitamin B(12) (or cyanocobalamin) on the different forms of Trypanosoma cruzi. Cyanocobalamin showed a marked antiparasitic activity against epimastigotes (50% inhibitory concentration [IC(50)], 2.42 ?M), amastigotes (IC(50), 10.69 ?M), and trypomastigotes (IC(50), 9.46 ?M). Anti-epimastigote and -trypomastigote values were 1.7 to 4 times lower than those obtained with the reference drug benznidazole (Bnz). We also found that B(12) and hemin do not interact with each other in their modes of action. Our results show that B(12) increases intracellular oxidative activity and stimulates both superoxide dismutase (50%) and ascorbate peroxidase (20%) activities, while the activity of trypanothione reductase was not modified. In addition, we found that the antioxidants dithiothreitol and ascorbic acid increase the susceptibility of the parasite to the cytotoxic action of B(12). We propose that vitamin B(12) exerts its growth-inhibitory effect through the generation of reactive oxygen species. In an in vivo assay, a significant reduction in the number of circulating parasites was found in T. cruzi-infected mice treated with cyanocobalamin and ascorbic acid. The reduction of parasitemia in benznidazole-treated mice was improved by the addition of these vitamins. According to our results, a combination of B(12) and Bnz should be further investigated due to its potential as a new therapeutic modality for the treatment of Chagas' disease. PMID:22869565

Ciccarelli, Alejandra B; Frank, Fernanda M; Puente, Vanesa; Malchiodi, Emilio L; Batlle, Alcira; Lombardo, Maria Elisa

2012-10-01

55

Antiparasitic Effect of Vitamin B12 on Trypanosoma cruzi  

PubMed Central

A nutritional characteristic of trypanosomatid protozoa is that they need a heme compound as a growth factor. Because of the cytotoxic activity of heme and its structural similarity to cobalamins, we have investigated the in vitro and in vivo effect of vitamin B12 (or cyanocobalamin) on the different forms of Trypanosoma cruzi. Cyanocobalamin showed a marked antiparasitic activity against epimastigotes (50% inhibitory concentration [IC50], 2.42 ?M), amastigotes (IC50, 10.69 ?M), and trypomastigotes (IC50, 9.46 ?M). Anti-epimastigote and -trypomastigote values were 1.7 to 4 times lower than those obtained with the reference drug benznidazole (Bnz). We also found that B12 and hemin do not interact with each other in their modes of action. Our results show that B12 increases intracellular oxidative activity and stimulates both superoxide dismutase (50%) and ascorbate peroxidase (20%) activities, while the activity of trypanothione reductase was not modified. In addition, we found that the antioxidants dithiothreitol and ascorbic acid increase the susceptibility of the parasite to the cytotoxic action of B12. We propose that vitamin B12 exerts its growth-inhibitory effect through the generation of reactive oxygen species. In an in vivo assay, a significant reduction in the number of circulating parasites was found in T. cruzi-infected mice treated with cyanocobalamin and ascorbic acid. The reduction of parasitemia in benznidazole-treated mice was improved by the addition of these vitamins. According to our results, a combination of B12 and Bnz should be further investigated due to its potential as a new therapeutic modality for the treatment of Chagas' disease. PMID:22869565

Ciccarelli, Alejandra B.; Frank, Fernanda M.; Puente, Vanesa; Malchiodi, Emilio L.

2012-01-01

56

Vitamin B12 and pteroylglutamic acid studies in the domestic fowl  

E-print Network

of folinic acid would tend to increase further the list of the functions of vitamin B12 ? Ling and Chow (f51) found that vitamin B12 influenced the glutathione concentrations in the liver and blood of the 2 rat. Vitamin B12 tlirough its effect... B-j g and methionine on the glutathione content of chick blood and liver................................. 51 Chapter 5. Summary ................................ 64 TABLE OF CONTENTS Tables Table 1. Effect of various levels of vitamin B12...

Reid, Bobby Leroy

2013-10-04

57

A review of vitamin B12 in dermatology.  

PubMed

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is important in the hematological and nervous systems, and it has a complex relationship with the skin. Altered cobalamin levels can lead to dermatological manifestations, which may indicate a deficiency or excess of this vitamin. The biochemistry and metabolism of cobalamin is complex, and diseases can be associated with alterations of this metabolic pathway. The cutaneous manifestations of cobalamin deficiency include hyperpigmentation (most commonly); hair and nail changes; and oral changes, including glossitis. Additionally, several dermatologic conditions, including vitiligo, aphthous stomatitis, atopic dermatitis, and acne are related to cobalamin excess or deficiency. The cutaneous complications of cobalamin therapy include acne, rosacea, and allergic site reactions, or anaphylaxis with cobalamin injections. As cobalt is a component of cobalamin, patients with cobalt sensitivity have been reported to have cutaneous manifestations when receiving cobalamin replacement therapy. PMID:25559140

Brescoll, Jennifer; Daveluy, Steven

2015-02-01

58

Folate, vitamin B12 and postmenopausal breast cancer in a prospective study of French women.  

E-print Network

Folate, vitamin B12 and postmenopausal breast cancer in a prospective study of French women. Martin and examine whether the relation is affected by alcohol and intake of vitamin B2 and B12. Methods intake. The decreasing trend was most marked in women with higher folate and vitamin B12 intake. However

Paris-Sud XI, Université de

59

Dietary source of vitamin B(12) intake and vitamin B(12) status in female elderly Koreans aged 85 and older living in rural area.  

PubMed

Recently, we found and analyzed vitamin B(12) in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B(12) intake and its dietary sources and the vitamin B(12) status in the very old elderly Koreans. We measured serum vitamin B(12) level and estimated the amounts of vitamin B(12) intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin B(12) concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin B(12) intake of our subjects was 3.2 microg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 microg/day. On dietary source, 67.3% of dietary vitamin B(12) was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin B(12) concentration was 450.5 pg/mL, and low serum vitamin B(12) (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B(12) intake was significantly lower in subjects with low serum vitamin B(12) (0.79 microg/day) than those with normal serum vitamin B(12) (3.47 microg/day). There were no significant difference in vitamin B(12) intake and its dietary sources and serum vitamin B(12) level between the 85-99 yr-old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B(12) status in very old elderly Koreans. PMID:20607069

Kwak, Chung Shil; Lee, Mee Sook; Lee, Hae Jeung; Whang, Jin Yong; Park, Sang Chul

2010-06-01

60

Uptake and transport of B12-conjugated nanoparticles in airway epithelium?  

PubMed Central

Non-invasive delivery of biotherapeutics, as an attractive alternative to injections, could potentially be achieved through the mucosal surfaces, utilizing nanoscale therapeutic carriers. However, nanoparticles do not readily cross the mucosal barriers, with the epithelium presenting a major barrier to their translocation. The transcytotic pathway of vitamin B12 has previously been shown to ‘ferry’ B12-decorated nanoparticles across intestinal epithelial (Caco-2) cells. However, such studies have not been reported for the airway epithelium. Furthermore, the presence in the airways of the cell machinery responsible for transepithelial trafficking of B12 is not widely reported. Using a combination of molecular biology and immunostaining techniques, our work demonstrates that the bronchial cell line, Calu-3, expresses the B12-intrinsic factor receptor, the transcobalamin II receptor and the transcobalamin II carrier protein. Importantly, the work showed that sub-200 nm model nanoparticles chemically conjugated to B12 were internalised and transported across the Calu-3 cell layers, with B12 conjugation not only enhancing cell uptake and transepithelial transport, but also influencing intracellular trafficking. Our work therefore demonstrates that the B12 endocytotic apparatus is not only present in this airway model, but also transports ligand-conjugated nanoparticles across polarised epithelial cells, indicating potential for B12-mediated delivery of nanoscale carriers of biotherapeutics across the airways. PMID:24008152

Fowler, Robyn; Vllasaliu, Driton; Falcone, Franco H.; Garnett, Martin; Smith, Bryan; Horsley, Helen; Alexander, Cameron; Stolnik, Snow

2013-01-01

61

Combined dietary folate, vitamin B-12, and vitamin B-6 intake influences plasma docosahexaenoic acid concentration in rats  

E-print Network

Background: Folate, vitamin B-12, and vitamin B-6 are essential nutritional components in one-carbon metabolism and are required for methylation capacity. The availability of these vitamins may therefore modify methylation ...

van Wijk, Nick

62

Vitamin B-12 deficiency and hyperhomocysteinemia are partly ameliorated by cobalt and nickel supplementation in pigs.  

PubMed

Vitamin B-12 deficiency and hyperhomocysteinemia alter the metabolism of trace elements. This study tested the hypothesis that there is a reverse relationship in which diets high in iron, copper, nickel and cobalt would influence vitamin B-12 deficiency outcomes including hyperhomocysteinemia. Piglets (German Landrace x Pietrain) were assigned to six groups of 8 and fed one of the following diets for 166 d: a vitamin B-12-adequate and folate-fortified diet (30 microg/kg vitamin B-12 and 0.5 mg/kg folate) with normal trace element concentrations or one of five vitamin B-12-free, folate nonsupplemented diets (0.36 mg/kg), with either normal trace element concentrations or high concentrations of iron (300 mg/kg), copper (30 mg/kg), cobalt (1 mg/kg) or nickel (6 mg/kg). Feed intake and weight gain did not differ significantly among the groups. Vitamin B-12-deficient pigs developed diminished serum and liver concentrations of vitamin B-12 and folate, an accumulation of iron in the liver and hyperhomocysteinemia. The magnitude of changes differed among vitamin B-12-deficient groups. Vitamin B-12-deficient pigs fed 6 mg/kg nickel had distinctly higher vitamin B-12 concentrations in liver and serum and 45% lower serum concentration of homocysteine than the corresponding deficiency group fed 1 mg/kg nickel; iron concentration in liver was completely normalized. Vitamin B-12-deficient pigs fed 1 mg/kg cobalt had 47% lower homocysteine concentrations in serum than the vitamin B-12-deficient group fed 0.13 mg/kg cobalt, but the vitamin B-12 status was unaffected. Supplementation of iron and copper did not affect these variables. The dietary manipulations had no detrimental effects on variables symptomatic of oxidative stress. The findings indicate a collaborative relationship between vitamin B-12 metabolism and the trace elements nickel and cobalt. PMID:11110865

Stangl, G I; Roth-Maier, D A; Kirchgessner, M

2000-12-01

63

Breast milk vitamin B-12 concentrations of Guatemalan women are correlated with maternal but not infant vitamin B12 status at 12 months postpartum  

Technology Transfer Automated Retrieval System (TEKTRAN)

In our previous studies one third of lactating Guatemalan women, infants and children had deficient or marginal serum vitamin B-12 concentrations. Relationships among maternal and infant status and breast milk vitamin B-12, however, have not been investigated in such populations. Our purpose was to ...

64

VITAMIN B-12 SUPPLEMENTATION OF DEFICIENT LACTATING GUATEMALAN WOMEN IMPROVES MATERNAL BUT NOT INFANT STATUS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin B-12 deficiency is common in mothers and infants where maternal intake of animals source foods is low. The first six months post-partum is a critical period of neurological development requiring vitamin B-12. A pilot study was designed to determine the dose of B-12 to the mothers that would ...

65

Development and application of an alpha-face-specific radioimmunoassay for vitamin B12.  

PubMed

The first development of an alpha-face-specific radioimmunoassay for vitamin B12 is described. Sheep, fed a cobalt-deficient diet, and immunized with a conjugate between Co-beta carboxypropyl cobalamin and keyhole limpet hemocyanin, were used to produce antisera. The antisera crossreacted with Co-beta derivatives of vitamin B12, but did not crossreact with the alpha-face vitamin B12 analog cobinamide. The antisera were used to develop a sensitive and reproducible radioimmunoassay that was free from contamination with the nonspecific vitamin B12 binding protein, R-protein. Both the radioimmunoassay and measurements of plasma concentrations of methylmalonic acid were applied to the diagnosis of cobalt/vitamin B12 deficiency in sheep. The assay correlated well with a commercially available radioassay and did not falsely detect normal vitamin B12 concentration in plasma samples containing elevated concentrations of methylmalonic acid. PMID:1280981

Kennedy, D G; Blanchflower, W J; Young, P B; Davidson, W B

1992-11-01

66

Biomarkers of vitamin B-12 status in NHANES: a roundtable summary123456  

PubMed Central

A roundtable to discuss the measurement of vitamin B-12 (cobalamin) status biomarkers in NHANES took place in July 2010. NHANES stopped measuring vitamin B-12–related biomarkers after 2006. The roundtable reviewed 3 biomarkers of vitamin B-12 status used in past NHANES—serum vitamin B-12, methylmalonic acid (MMA), and total homocysteine (tHcy)—and discussed the potential utility of measuring holotranscobalamin (holoTC) for future NHANES. The roundtable focused on public health considerations and the quality of the measurement procedures and reference methods and materials that past NHANES used or that are available for future NHANES. Roundtable members supported reinstating vitamin B-12 status measures in NHANES. They noted evolving concerns and uncertainties regarding whether subclinical (mild, asymptomatic) vitamin B-12 deficiency is a public health concern. They identified the need for evidence from clinical trials to address causal relations between subclinical vitamin B-12 deficiency and adverse health outcomes as well as appropriate cutoffs for interpreting vitamin B-12–related biomarkers. They agreed that problems with sensitivity and specificity of individual biomarkers underscore the need for including at least one biomarker of circulating vitamin B-12 (serum vitamin B-12 or holoTC) and one functional biomarker (MMA or tHcy) in NHANES. The inclusion of both serum vitamin B-12 and plasma MMA, which have been associated with cognitive dysfunction and anemia in NHANES and in other population-based studies, was preferable to provide continuity with past NHANES. Reliable measurement procedures are available, and National Institute of Standards and Technology reference materials are available or in development for serum vitamin B-12 and MMA. PMID:21593512

Pfeiffer, Christine M; Phinney, Karen W; Bailey, Regan L; Blackmore, Sheena; Bock, Jay L; Brody, Lawrence C; Carmel, Ralph; Curtin, L Randy; Durazo-Arvizu, Ramón A; Eckfeldt, John H; Green, Ralph; Gregory, Jesse F; Hoofnagle, Andrew N; Jacobsen, Donald W; Jacques, Paul F; Lacher, David A; Molloy, Anne M; Massaro, Joseph; Mills, James L; Nexo, Ebba; Rader, Jeanne I; Selhub, Jacob; Sempos, Christopher; Shane, Barry; Stabler, Sally; Stover, Patrick; Tamura, Tsunenobu; Tedstone, Alison; Thorpe, Susan J; Johnson, Clifford L; Picciano, Mary Frances

2011-01-01

67

Development and application of an ?-face-specific radioimmunoassay for vitamin B 12  

Microsoft Academic Search

The first development of an ?-face-specific radioimmunoassay for vitamin B12 is described. Sheep, fed a cobalt-deficient diet, and immunized with a conjugate between Co-? carboxypropyl cobalamin and\\u000a keyhole limpet hemocyanin, were used to produce antisera. The antisera crossreacted with Co-? derivatives of vitamin B12, but did not crossreact with the ?-face vitamin B12 analog cobinamide. The antisera were used to

D. Glenn Kennedy; W. John Blanchflower; Paul B. Young; W. Brian Davidson

1992-01-01

68

Intestinal Synthesis and Dietary Nonessentiality of Vitamin B12 for Tilapia nilotica  

Microsoft Academic Search

A feeding experiment with purified diets was conducted in a controlled environment to study intestinal synthesis and dietary essentiality of vitamin B12 in Tilapia nilotica. Intestinal microorganisms in T. nilotica fed a vitamin B12-deficient diet synthesized at least 11.2 ng of vitamin B12 per g of body weight per day. Removal of cobalt from the diet or supplementation with an

Richard T. Lovell; Tasanee Limsuwan

1982-01-01

69

Synthesis and characterization of polypyrrole–magnetite–vitamin B12 hybrid composite electrodes  

Microsoft Academic Search

In this study vitamin B12 covered magnetite nanoparticles have been incorporated into a conducting polypyrrole. This polymer\\u000a was electrochemically synthesized in the presence of the B12-coated magnetite. The adsorption of B12 was demonstrated by the\\u000a decrease in absorbance of the vitamin in the supernatant liquid after B12 has been in contact with magnetite sol overnight.\\u000a The composition of the layers

Csaba Janaky; Balazs Endrodi; Angela Hajdu; Csaba Visy

2010-01-01

70

Competitive chemiluminescent enzyme immunoassay for vitamin B12 analysis in human milk  

Technology Transfer Automated Retrieval System (TEKTRAN)

BACKGROUND Few accurate data exist on the concentration of vitamin B12 in human milk. Binding of the vitamin to haptocorrin (HC) can interfere with the assay if not removed by pretreatment, and very low values can occur in women with poor B12 status. This study evaluated two competitive enzyme bind...

71

Intestinal synthesis and absorption of vitamin B-12 in channel catfish  

SciTech Connect

A feeding experiment conducted in a controlled environment and using a vitamin B12-deficient, but otherwise nutritionally complete, purified diet revealed that intestinal microorganisms in channel catfish synthesized approximately 1.4 ng of vitamin B12 per gram of bodyweight per day. Removal of cobalt from the diet or supplementation with an antibiotic (succinylsulfathiazole) significantly reduced the rate of intestinal synthesis and liver stores of vitamin B12. Radiolabeled vitamin B12 in the blood, liver, kidneys, and spleen of fish fed 60Co in the diet indicated that the intestinally synthesized vitamin was absorbed by the fish. The primary route of absorption was directly from the digestive tract into the blood because coprophagy was prevented in the rearing aquariums and the amount of vitamin B12 dissolved in the aquarium water was too low for gill absorption. Dietary supplementation of vitamin B12 was not necessary for normal growth and erythrocyte formation in channel catfish in a 24-week feeding period. A longer period, however, may have caused a vitamin deficiency since liver-stored vitamin B 12 decreased between the 2nd and 24th weeks.

Limsuwan, T.; Lovell, R.T.

1981-12-01

72

Binding interactions of ?-conglycinin and glycinin with vitamin B12.  

PubMed

Vitamin B12 deficiency is a problem for many elderly people around the world that is caused by food-cobalamin malabsorption syndrome due to gastrointestinal problems. In this study, the molecular interactions of VB12 with two major soy protein fractions, ?-conglycinin (7S) and glycinin (11S), were studied using fluorescence and far-UV circular dichroism spectroscopic techniques. The results show that the fluorescence of 7S and 11S was quenched by VB12 through binding-related quenching after correcting for the inner-filter effect. Both 7S and 11S had a good affinity to VB12 as indicated by their high binding constant 1.252 (±0.085) × 10(4) M(-1) for 7S and 0.952 (±0.04) × 10(4) M(-1) for 11S at 292 K, respectively. Such binding induced a more organized protein confirmation with increased ?-sheet and ?-turn structure components and a more folded tertiary structure. It is deduced that VB12 was bound in the interior of protein three-dimensional network mainly via hydrophobic interactions to form 7S-VB12 and 11S-VB12 complexes. The results suggest that soy protein has potential to be used as carrier of VB12. PMID:24131217

Zhang, Jing; Tian, Zhigang; Liang, Li; Subirade, Muriel; Chen, Lingyun

2013-11-14

73

Vitamin B-12 supplementation of rural Mexican women changes biochemical B-12 status indicators but does not affect hematology or a bone turnover marker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Based on the high prevalence of low serum vitamin B-12 concentrations and low dietary intake of the vitamin in Latin American studies including research in Mexico, it appears that vitamin B-12 deficiency is common. Whether this is associated with adverse effects on human function is unknown. To eval...

74

Persistence of neurological damage induced by dietary vitamin B-12 deficiency in infancy  

PubMed Central

Accepted 9 April 1997? A case is reported of a 14 month old boy with severe dietary vitamin B-12 deficiency caused by his mother's vegan diet. Cinical, electroencephalography (EEG), and haematological findings are described. Cranial magnetic resonance imaging (MRI) showed severe frontal and frontoparietal cranial atrophy. Vitamin B-12 supplements led to a rapid improvement of haematological and neurological symptoms. Serum vitamin B-12 and urinary methylmalonate excretion were normal 10 days after treatment began. After six weeks, EEG was normal and cranial MRI after 10 weeks showed complete disappearance of all structural abnormalities. Cognitive and language development, however, remained seriously retarded at the age of 2 years. It is concluded that infantile vitamin B-12 deficiency induced by maternal vegan diets may cause lasting neurodisability even though vitamin B-12 supplementation leads to rapid resolution of cerebral atrophy and electroencephalographic abnormality.?? PMID:9301352

von Schenck, U.; Bender-Gotze, C.; Koletzko, B.

1997-01-01

75

Metabolie Changes in Golden Hamsters Fed Vitamin B12Deficient Diets12  

Microsoft Academic Search

Various metabolic changes were observed in male hamsters fed vitamin B-12-deficient diets with or without supplements of cobalt, methionine, and a previously untested cobalt-free pseudovitamin B-12. The effects observed after 31 weeks of consuming the vitamin B-12-defìcient diets included a marked increase in the urinary excretion of both methyl- malonic acid and formiminoglutamic acid, slight increases in red blood cell

ROSE Y. L. TSENG; NINA L. COHÃ

76

Über das Vitamin B 12 -Bedürfnis phototropher Schwefelbakterien  

Microsoft Academic Search

1.10 von 19 Chlorobium-Stämmen, die mit einer Vit. B12-haltigen Nährlösung aus verschiedenen Gewässern in Kalifornien, Norwegen und Deutschland isoliert waren, erwiesen sich als Vit. B12-bedürftig.2.Bei Vit. B12-bedürftigen Chlorobium- und Chromatium-Stämmen wurde der Chlorophyllgehalt der Kulturen in Abhängigkeit von der Vit. B12-Konzentration quantitativ bestimmt. Zur Bildung vergleichbarer Erträge benötigten alle untersuchten Chlorobium-Stämme gegenüber den Chromatium-Stämmen etwa zehnmal höhere Vit. B12-Konzentrationen.3.Der Vergleich

Norbert Pfennig; Klaus Dieter Lippert

1966-01-01

77

Vitamin B12 levels in ewe colostrum and milk and in lamb serum  

E-print Network

Short note Vitamin B12 levels in ewe colostrum and milk and in lamb serum JJ Ramos T Saez JP Bueso 1993; accepted 4 February 1994) Summary ― Vitamin B!2 was measured in samples of normal ovine d. Colostrum obtained within 24 h of lambing contained high concentrations of vitamin B!2

Paris-Sud XI, Université de

78

Solid food refusal as the presenting sign of vitamin B 12 deficiency in a breastfed infant  

Microsoft Academic Search

Dietary vitamin B12 (vitB12) deficiency, although common in the elderly, is rare in childhood. We report on an exclusively breastfed 8-month-old infant,\\u000a presenting with persistent refusal of solid foods. Three months later, developmental regression and failure to thrive led\\u000a to the diagnosis of vitB12 deficiency, as a consequence of a subclinical pernicious anaemia with vitB12 deficiency in the mother. Treating

Els Ide; Stephanie Van Biervliet; Joke Thijs; Saskia Vande Velde; Ruth De Bruyne; Myriam Van Winckel

79

The use of blood concentrations of vitamins and their respective functional indicators to define folate and vitamin B12 status  

Technology Transfer Automated Retrieval System (TEKTRAN)

In recent years there has been growing interest in the vitamins folic acid and vitamin B12 because of the realization that the status of these vitamins in populations is less than adequate, and that such inadequacy may be linked to adverse public health outcomes. This concern has prompted the United...

80

A SIMPLIFIED METHOD FOR THE URINARY EXCRETION TEST OF ABSORPTION OF COBALT 60 LABELLED VITAMIN B12  

PubMed Central

It is possible to do both radioiodine uptake studies and urinary excretion tests for absorption of Cobalt 60 vitamin B12 with the same basic equipment. If a spectrometer is used and the samples properly prepared, the latter procedure can be performed quickly, accurately and with a minimum of laboratory equipment. This is a distinct advantage to a small laboratory with limited facilities, and should help to make both of these useful tests available for clinical use. ImagesFigure 1. PMID:13608296

Corbus, Howard F.; Nielson, Henry

1958-01-01

81

Most harmful algal bloom species are vitamin B1 and B12 auxotrophs  

PubMed Central

Eutrophication can play a central role in promoting harmful algal blooms (HABs), and therefore many HAB studies to date have focused on macronutrients (N, P, Si). Although a majority of algal species require exogenous B vitamins (i.e., auxotrophic for B vitamins), the possible importance of organic micronutrients such as B vitamins (B1, B7, B12) in regulating HABs has rarely been considered. Prior investigations of vitamins and algae have examined a relatively small number of dinoflagellates (n = 26) and a paucity of HAB species (n = 4). In the present study, the vitamin B1, B7, and B12 requirements of 41 strains of 27 HAB species (19 dinoflagellates) were investigated. All but one species (two strains) of harmful algae surveyed required vitamin B12, 20 of 27 species required B1, and 10 of 27 species required B7, all proportions higher than the previously reported for non-HAB species. Half-saturation (Ks) constants of several HAB species for B1 and B12 were higher than those previously reported for other phytoplankton and similar to vitamin concentrations reported in estuaries. Cellular quotas for vitamins suggest that, in some cases, HAB demands for vitamins may exhaust standing stocks of vitamins in hours to days. The sum of these findings demonstrates the potentially significant ecological role of B-vitamins in regulating the dynamics of HABs. PMID:21068377

Tang, Ying Zhong; Koch, Florian; Gobler, Christopher J.

2010-01-01

82

[Vitamin B12 and iron deficiencies: from diagnostic to follow-up].  

PubMed

Vitamin B12 and iron deficiencies are common problems in consultations of general internal medicine. They cause different symptoms that can be non-specific. This article makes it possible, from a clinical frame of reference, to answer the following questions: What value of vitamin B12 should we consider a "deficiency", and what is the role of methylmalonate? What is the role of vitamin B12 oral supplements? How should we interpret values of ferritine? How should iron deficiency be investigated? What is the place of intravenous iron administration? PMID:22792601

Bosco, C; Favrat, B; Cheseaux, M

2012-06-20

83

FRACTION OF TOTAL PLASMA VITAMIN B12 BOUND TO TRANSCOBALAMIN CORRELATES WITH COGNITIVE FUNCTION IN ELDERLY LATINOS WITH DEPRESSIVE SYMPTOMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: The fraction of total plasma vitamin B12 bound to transcobalamin (holoTC/B12 ratio) may reflect tissue levels of the vitamin, but its clinical relevance is unclear. Methods: associations between cognitive function and total B12, holoTC, and holoTC/B12 ratio were assessed in a cohort of ...

84

Prevalent vitamin B-12 deficiency in twelve-month-old Guatemalan infants is predicted by maternal B-12 deficiency and infant diet  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marginal (<148 pmol/L) or deficient (148-220 pmol/L) plasma vitamin B-12 concentrations were reported previously in approximately one third of low-income women and children studied in Guatemala. Since vitamin B-12 deficiency can adversely affect infant development and cognitive function, this study ...

85

Cerebral Atrophy in a Vitamin B12-deficient Infant of a Vegetarian Mother  

PubMed Central

ABSTRACT In developed countries, vitamin B12 (cobalamin) deficiency usually occurs in children, exclusively breastfed ones whose mothers are vegetarian, causing low body stores of vitamin B12. The haematologic manifestation of vitamin B12 deficiency is pernicious anaemia. It is a megaloblastic anaemia with high mean corpuscular volume and typical morphological features, such as hyperlobulation of the nuclei of the granulocytes. In advanced cases, neutropaenia and thrombocytopaenia can occur, simulating aplastic anaemia or leukaemia. In addition to haematological symptoms, infants may experience weakness, fatigue, failure to thrive, and irritability. Other common findings include pallor, glossitis, vomiting, diarrhoea, and icterus. Neurological symptoms may affect the central nervous system and, in severe cases, rarely cause brain atrophy. Here, we report an interesting case, a 12-month old infant, who was admitted with neurological symptoms and diagnosed with vitamin B12 deficiency. PMID:25076673

Akin, Fatih; Çaksen, Hüseyin; Böke, Saltuk Bu?ra; Arslan, ?ükrü; Aygün, Serhat

2014-01-01

86

Rapid determination of vitamin B2 and B12 in human urine by isocratic liquid chromatography.  

PubMed

A simple and rapid method for the identification and quantification of vitamin B(2) and B(12) in human urine has been developed using reverse phase high performance liquid chromatography (HPLC) and the peaks identity were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). HPLC separation was performed in single wavelength detector (lambda(365)) mode and separated isocratically using mobile phase methanol: 1mM aqueous TFA (1:4) in C18 column. The calibration graphs plotted with different concentrations of vitamin B(2) and B(12) was linear with a correlation coefficients (r(2))=0.9975 and 0.9985, respectively. The recoveries of vitamin B(2) and B(12) were above 87% and 90%, respectively. The results of this present study suggest that the proposed method may be simple and convenient way of identifying and quantifying vitamin B(2) and B(12) from human urine. PMID:19362629

Mandal, Santi M; Mandal, Mahitosh; Ghosh, Ananta K; Dey, Satyahari

2009-04-27

87

THE EFFECT OF DIETARY COBALT INTAKE ON THE PLASMA VITAMIN B12 CONCENTRATION OF SHEEP  

Microsoft Academic Search

The plasma vitamin B12 concentration of sheep progressively increased as the dietary cobalt level was raised from 0·04 parts per million to 0·34 parts per million. With rations containing more than 0·10 parts per million cobalt (8·1 ?g. Co\\/day) plasma vitamin B12 concentrations of sheep were more variable than those with lower cobalt intakes. This variability may have been due

M Somers; JM Gawthorne

1969-01-01

88

Intestinal synthesis and absorption of vitamin B12 in channel catfish  

Microsoft Academic Search

A feeding experiment conducted in a controlled environment and using a vitamin B12-deficient, but otherwise nutritionally complete, purified diet revealed that intestinal microorganisms in channel catfish synthesized approximately 1.4 ng of vitamin B12 per gram of bodyweight per day. Removal of cobalt from the diet or supplementation with an antibiotic (succinylsulfathiazole) significantly reduced the rate of intestinal synthesis and liver

T. Limsuwan; R. T. Lovell

1981-01-01

89

Vitamin B(12) synthesis and salvage pathways were acquired by horizontal gene transfer to the Thermotogales.  

PubMed

The availability of genome sequences of Thermotogales species from across the order allows an examination of the evolutionary origins of phenotypic characteristics in this lineage. Several studies have shown that the Thermotogales have acquired large numbers of genes from distantly related lineages, particularly Firmicutes and Archaea. Here, we report the finding that some Thermotogales acquired the ability to synthesize vitamin B(12) by acquiring the requisite genes from these distant lineages. Thermosipho species, uniquely among the Thermotogales, contain genes that encode the means to synthesize vitamin B(12) de novo from glutamate. These genes are split into two gene clusters: the corrinoid synthesis gene cluster, that is unique to the Thermosipho and the cobinamide salvage gene cluster. The corrinoid synthesis cluster was acquired from the Firmicutes lineage, whereas the salvage pathway is an amalgam of bacteria- and archaea-derived proteins. The cobinamide salvage gene cluster has a patchy distribution among Thermotogales species, and ancestral state reconstruction suggests that this pathway was present in the common Thermotogales ancestor. We show that Thermosipho africanus can grow in the absence of vitamin B(12), so its de novo pathway is functional. We detected vitamin B(12) in the extracts of T. africanus cells to verify the synthetic pathway. Genes in T. africanus with apparent B(12) riboswitches were found to be down-regulated in the presence of vitamin B(12) consistent with their roles in B(12) synthesis and cobinamide salvage. PMID:22798452

Swithers, Kristen S; Petrus, Amanda K; Secinaro, Michael A; Nesbø, Camilla L; Gogarten, J Peter; Noll, Kenneth M; Butzin, Nicholas C

2012-01-01

90

Evaluation of vitamin B12 effects on DNA damage induced by paclitaxel.  

PubMed

Paclitaxel (PAC) is an anticancer drug that has been shown to generate free radicals leading to irreversible cell injury. Vitamin B12 has antioxidative properties and can protect DNA from free radicals. In this study, we examined the possible genotoxic effect of PAC on DNA as well as the possible protective effect of vitamin B12 on DNA damage induced by paclitaxel. Sister chromatid exchanges (SCEs), chromosomal aberrations (CAs) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were measured in cultured human blood lymphocytes treated with PAC (10 µM) and/or vitamin B12 (2.7 mg/mL). Our results showed that PAC significantly increased the frequencies of SCEs (p < 0.001) and CAs (p < 0.001) in human blood lymphocytes, as compared to controls. These DNA damages, caused by PAC drug, were prevented by pretreatment of cells with vitamin B12. In addition, we showed that PAC induced an increase in 8-OHdG, a marker of oxidative DNA damage, and that this increase was prevented by vitamin B12. Vitamin B12 seems to protect against genotoxicity induced by PAC in human blood lymphocytes. PMID:24215581

Alzoubi, Karem; Khabour, Omar; Khader, Manal; Mhaidat, Nizar; Al-Azzam, Sayer

2014-07-01

91

Influence of vitamin B 12 and light on the formation of chlorosomes in green- and brown-colored Chlorobium species  

Microsoft Academic Search

The specific Bchl a and c content of the vitamin B12-dependent Chlorobium limicola strain 1230 decreased strongly under vitamin B12 limitation. In comparison to a regularly grown culture (20 µg vitamin B12\\/l) the specific Bchl c content of a B12-limited culture was reduced to 20% and the specific Bchl a content to 42%. By ultrathin sections it could be clearly

Sabine Fuhrmann; Jiirg Overmann; Norbert Pfennig; Ulrich Fischer

1993-01-01

92

TENEUR EN VITAMINE B12 DU FOIE ET DU CONTENU DE L'INTESTIN  

E-print Network

V. - TENEUR EN VITAMINE B12 DU FOIE ET DU CONTENU DE L'INTESTIN R. F�VRIER, J. P. VACHEL M. MICHEL relations encore mal connues entre l'action des antibiotiques et le métabolisme de la vitamine Bi2. Pour obtenir des informations plus complètes sur ce point, nous avons effectué des dosages de vitamine Bi2 sur

Boyer, Edmond

93

Folate and vitamin B12 status of adolescent girls in northern Nigeria.  

PubMed Central

The diets of populations in many developing countries are low in folate and vitamin B12 and a deficiency of either of these vitamins results in increased risk for cardiovascular disease and neural tube defects. The rates of neural tube defects in Nigeria are among the highest reported worldwide. Since many girls marry at an early age in northern Nigeria, we therefore determined the folate and vitamin B12 status of adolescent girls between 12 and 16 years of age in Maiduguri, Nigeria. The mean serum folate concentration for subjects was 15.3 +/- 5.2 nmol/L. Whereas only four subjects (2.4%) had serum folate concentrations lower than 6.8 nmol/L, a level indicative of negative folate balance, 9% of the subjects had serum vitamin B12 concentrations at or below 134 pmol/L, the lower limit of the reference range for their age group. Serum homocysteine was measured in 56 of the 162 subjects and the mean level was 15.9 +/- 5.0 mumol/L. The majority of subjects had serum homocysteine concentrations above the upper limit of the reference range for their age group. We conclude that the adolescent girls we studied were at greater risk for vitamin B12 deficiency than folate deficiency. This conclusion is consistent with the fact that their diet included few foods that contained vitamin B12. PMID:10946529

VanderJagt, D. J.; Spelman, K.; Ambe, J.; Datta, P.; Blackwell, W.; Crossey, M.; Glew, R. H.

2000-01-01

94

Vitamins  

MedlinePLUS

... Vitamin D Vitamin E Vitamin K Vitamin B1 ( thiamine ) Vitamin B2 ( riboflavin ) Vitamin B3 ( niacin ) Pantothenic acid ... in the body. Vitamin B12 , like the other B vitamins, is important for metabolism. It also helps form ...

95

Intergenotypic variation of Vitamin B12 and Folate in AD: In north indian population  

PubMed Central

Objectives: Changes in lifestyle habits such as diet modification or supplementation have been indicated as probable protective factors for a number of chronic conditions including Alzheimer's disease (AD). With this background, we aim to hypothesize that whether C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene contributes towards the risk of developing AD and its association with vitamin B12 and folate levels. Materials and Methods: A case-control study comprising of total 200 subjects, within the age group of 50-85 years. Their blood samples were analyzed for serum folate, vitamin B12 levels, and MTHFR C677T polymorphism by restriction fragment length polymorphism (RFLP). Results: The mean plasma levels of vitamin B12 and folate were significantly lower in study group when compared to the control group (P < 0.001). Genotypic and allelic frequency of MTHFR gene in both groups was found to be significant (P < 0.05). The intergenotypic variations of vitamin B12 and folate were found to be significant (P < 0.001). Conclusion: We concluded that the subjects with homozygous mutated alleles are more prone to AD and also pointed out the influence of presence/absence of MTHFR T allelic variants on serum folate and vitamin B12 levels. PMID:25221401

Chhillar, Neelam; Singh, Neeraj Kumar; Banerjee, Basu Dev; Bala, Kiran; Basu, Mitra; Sharma, Deepika

2014-01-01

96

Vitamin B12 deficiency with combined hematological and neuropsychiatric derangements: a case report  

PubMed Central

Introduction Although vitamin B12 deficiency is a well-known cause of hematological and neuropsychiatric illness, the presentation of combined severe pancytopenia, demyelination and prominent psychiatric impairment is rare. Case presentation We present a case of a previously healthy 55-year-old East African man with severe vitamin B12 deficiency (serum vitamin B12 22pmol/L) secondary to pernicious anemia. He had a severe hypoproliferative megaloblastic anemia with hemolysis (hemoglobin 61g/L, mean corpuscular volume 99fL, reticulocytes 0.8%, haptoglobin undetectable), leukopenia (2.7×109/L), thrombocytopenia (96×109/L), ataxia with central demyelination, and megaloblastic madness. The patient’s anemia, myelopathy and psychiatric condition responded well to parenteral vitamin B12 replacement therapy, with significant improvement seen within weeks. Conclusion Hematological manifestations of vitamin B12 deficiency are typically inversely correlated with the presence and severity of neuropsychiatric impairment. Although uncommon, a presentation with severe hematological and neuropsychiatric disease can occur, as illustrated by this case. Its presence may help guide diagnosis as well as provide clinically important prognostic information. PMID:25128288

2014-01-01

97

Vitamin B12 deficiency with intrinsic factor antibodies in an infant with poor growth and developmental delay.  

PubMed

Vitamin B12 deficiency is very rare in infants and may lead to serious hematological and neurodevelopmental abnormalities. The present article describes a case involving a seven-month-old boy with severe vitamin B12 deficiency, likely caused by juvenile pernicious anemia, an entity rarely described. The child presented with feeding intolerance, poor growth and developmental delay. He was noted to have macrocytic anemia, a markedly low serum vitamin B12 level, and elevated homocysteine and methylmalonic acid levels. Antibodies to intrinsic factor were positive. The mother was healthy, with normal vitamin B12 status. Therapy with vitamin B12 supplements led to excellent recovery of symptoms. Vitamin B12 deficiency should be considered in children presenting with failure to thrive, especially when compounded with neurological symptoms. Early diagnosis and adequate treatment is essential to avoid serious complications. PMID:24596481

McNeil, Kathleen; Chowdhury, Dhiman; Penney, Lynette; Rashid, Mohsin

2014-02-01

98

Low Vitamin B12 Levels among Newly-Arrived Refugees from Bhutan, Iran and Afghanistan: A Multicentre Australian Study  

PubMed Central

Background Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian states and territories. Methods In a cross-sectional descriptive study, we collected Vitamin B12, folate and haematological indices on all refugees (n?=?916; response rate 94% of eligible population) who had been in Australia for less than one year, and attended one of the collaborating health services between July 2010 and July 2011. Results 16.5% of participants had Vitamin B12 deficiency (<150 pmol/L). One-third of participants from Iran and Bhutan, and one-quarter of participants from Afghanistan had Vitamin B12 deficiency. Contrary to our hypothesis, low Vitamin B12 levels were more prevalent in males than females. A higher prevalence of low Vitamin B12 was also reported in older age groups in some countries. The sensitivity of macrocytosis in detecting Vitamin B12 deficiency was only 4.6%. Conclusion Vitamin B12 deficiency is an important population health issue in newly-arrived refugees from many countries. All newly-arrived refugees should be tested for Vitamin B12 deficiency. Ongoing research should investigate causes, treatment, and ways to mitigate food insecurity, and the contribution of such measures to enhancing the health of the refugee communities. PMID:23469126

Benson, Jill; Phillips, Christine; Kay, Margaret; Webber, Murray T.; Ratcliff, Alison J.; Correa-Velez, Ignacio; Lorimer, Michelle F.

2013-01-01

99

Lessons to be learned: a case study approach. Vitamin B12 deficiency of nutritional origin.  

PubMed

The case is presented of a 14 year old boy who developed severe anaemia at the onset of puberty caused by nutritional deficiency of vitamin B12 of about 10 years duration. The dietary intake comprised mainly chips, ice-cream, fruit and Coca-Cola--with small amounts of vitamin B12 from occasional slices of chicken meat. His denial of abnormal nutritional intake, supported by his mother, delayed confirmation of the correct diagnosis. However, the true situation was eventually confessed--and following implementation of a normal diet he rapidly improved clinically, the haemoglobin value rose to normal and he subsequently remained well. PMID:9519663

Donaldson, D

1997-10-01

100

Low serum vitamin B12 levels among psychiatric patients admitted in Butabika mental hospital in Uganda  

PubMed Central

Background Psychiatric manifestations have been noted in patients with low serum vitamin B12 levels even in the absence of other neurologic and/or haematologic abnormalities. There is no literature on low serum B12 prevalence among Ugandans with psychiatric illnesses. The aim of this study was to establish the prevalence, risk factors, and clinical manifestations of low serum vitamin B12 among psychiatric patients admitted in a Mental Health Hospital in Uganda. Method Using a cross sectional descriptive study design, 280 in-patients selected by systematic sampling were studied using a standardized protocol. Low serum vitamin B12 was defined as a level?B12 in 28.6% of the participants. Absent vibration sense which was significantly associated (58.3% Vs. 26.7%: OR?=?3.84 (95% C.I. 1.18, 12.49); p-value?=?0.025) with low vitamin B12 was observed among 12 participants. Macro-ovalocytes present among 23 participants on peripheral film were significantly associated with low serum levels (73.9% Vs. 26.2%: OR?=?7.99 (95% C.I. 3.01, 21.19) p-value?B12 levels included psychiatric diagnosis of schizophrenia (AOR 1.74 (95% C.I. 1.00, 3.02); p-value?=?0.049), duration of psychiatric illness?>?or?=?3 years (AOR 2.27 (95% C.I. 1.29, 3.98); p-value?=?0.004), and hospitalization?B12 is common among hospitalized psychiatric patients with the majority having no haematological findings. Associated risk factors included having a psychiatric diagnosis of schizophrenia, a shorter duration of hospitalization and longer duration of psychiatric illness. Female participants were less likely to have low serum vitamin B12 levels. Routine screening for serum vitamin B12 levels should be adopted by all hospitals for admitted psychiatric patients. PMID:24533701

2014-01-01

101

Decreased vitamin B12 availability induces ER stress through impaired SIRT1-deacetylation of HSF1.  

PubMed

Vitamin B12 (cobalamin) is a key determinant of S-adenosyl methionine (SAM)-dependent epigenomic cellular regulations related to methylation/acetylation and its deficiency produces neurodegenerative disorders by elusive mechanisms. Sirtuin 1 deacetylase (SIRT1) triggers cell response to nutritional stress through endoplasmic reticulum (ER) stress. Recently, we have established a N1E115 dopaminergic cell model by stable expression of a transcobalamin-oleosin chimera (TO), which impairs cellular availability of vitamin B12, decreases methionine synthase activity and SAM level, and reduces cell proliferation. In contrast, oleosin-transcobalamin chimera (OT) does not modify the phenotype of transfected cells. Presently, the impaired cellular availability of vitamin B12 in TO cells activated irreversible ER stress pathways, with increased P-eIF-2?, P-PERK, P-IRE1?, ATF6, ATF4, decreased chaperon proteins and increased pro-apoptotic markers, CHOP and cleaved caspase 3, through reduced SIRT1 expression and consequently greater acetylation of heat-shock factor protein 1 (HSF1). Adding either B12, SIRT1, or HSF1 activators as well as overexpressing SIRT1 or HSF1 dramatically reduced the activation of ER stress pathways in TO cells. Conversely, impairing SIRT1 and HSF1 by siRNA, expressing a dominant negative form of HSF1, or adding a SIRT1 inhibitor led to B12-dependent ER stress in OT cells. Addition of B12 abolished the activation of stress transducers and apoptosis, and increased the expression of protein chaperons in OT cells subjected to thapsigargin, a strong ER stress stimulator. AdoX, an inhibitor of methyltransferase activities, produced similar effects than decreased B12 availability on SIRT1 and ER stress by a mechanism related to increased expression of hypermethylated in cancer 1 (HIC1). Taken together, these data show that cellular vitamin B12 has a strong modulating influence on ER stress in N1E115 dopaminergic cells. The impaired cellular availability in vitamin B12 induces irreversible ER stress by greater acetylation of HSF1 through decreased SIRT1 expression, whereas adding vitamin B12 produces protective effects in cells subjected to ER stress stimulation. PMID:23519122

Ghemrawi, R; Pooya, S; Lorentz, S; Gauchotte, G; Arnold, C; Gueant, J-L; Battaglia-Hsu, S-F

2013-01-01

102

[Anemias due to disorder of folate, vitamin B12 and transcobalamin metabolism].  

PubMed

Macrocytic megaloblastic anemia is the most typical but the latest sign of a cobalamin (vitamin B12) and/or folic acid deficiency or of a congenital abnormality of cobalamin and folate metabolism. Macrocytosis in blood and megaloblastosis in bone marrow are the morphological features of a disturbance in cell division related to a defect in DNA biosynthesis. Macrocytosis without anemia, normocytic normochronic anemia with a low reticulocyte cell count or microcytic hypochromic anemia in case of associated iron deficiency do not exclude a vitamin deficiency. Neurological or psychiatric disorders and immune abnormalities have been reported in patients with vitamin B12 or folate deficiencies or in children with congenital abnormalities of these 2 vitamins; such manifestations may even occur without anemia. PMID:8235383

Zittoun, J

1993-06-01

103

Separation of Vitamin B2 and B12 by Impregnate HPTLC Plates with Boric Acid  

E-print Network

Abstract—A high performance thin layer chromatography system (HPTLC) for the separation of vitamin B2 and B12 has been developed. The separation was successfully using a solvent system of methanol, water, ammonia 7.3.1 (V/V) as mobile phase on HPTLC plates impregnated with boric acid. The effect of other mobile phases on the separation of vitamins was also examined. The method is based on different behavior of investigated compounds in impregnated TLC plates with different amount of boric acid. The Rf values of vitamin B2 and B12 are considered on non impregnated and impregnated silica gel HPTLC plate with boric acid. The effect of boric acid in the mobile phase and on HPTLC plates on the RF values of the vitamins has also been studied. Keywords—High performance thin layer chromatography,

Homayon Ahmad Panahi; Hossein Sid Kalal; Atyeh Rahimi

104

Effects of Formulation Variables and Storage Conditions on Light Protected Vitamin B12 Mixed Parenteral Formulations  

PubMed Central

Purpose: In this research the effect of vitamin B1 and B6 on cyanocobalamin stability in commercial light protected parenteral formulations and upon adding stabilizing agents will be investigated and best formulation composition and proper storage condition will be introduced. Methods: In this research some additives such as co solvents and tonicity adjusters, surfactants, antioxidants and chelating agents as well as buffer solutions, were used to improve the stability of the parenteral mixed formulations of B12 in the presence of other B vitamins (B1 and B6). Screening tests and accelerated stability tests were performed according to ICH guidelines Q1A (R2). Results: Shelf life evaluation revealed the best formulation and the proper storage condition. The results indicated the first kinetic models for all tested formulations and the optimum pH value was determined to be 5.8. There was no evidence of B12 loss when mixed with B1 and B6 in a medical syringe at room temperature for maximum of 8 hours. Conclusion: It is necessary to formulate vitamin B12 mixed parenteral solutions using proper phosphate buffers (pH=5.8) and to indicate “Store in refrigerator” on the mixed parenteral formulations of vitamin B12 with other B vitamins, which has not been expressed on the label of tested Brand formulations at the time of this study. PMID:25436187

Monajjemzadeh, Farnaz; Ebrahimi, Fatemeh; Zakeri-Milani, Parvin; Valizadeh, Hadi

2014-01-01

105

Folate, Vitamin B6, Vitamin B12, and Methionine Intakes and Risk of Stroke Subtypes in Male Smokers  

Microsoft Academic Search

The associations of dietary folate, vitamin B6, vitamin B12, and methionine intakes with risk of stroke subtypes were examined among 26,556 male Finnish smokers, aged 50-69 years, enrolled in the Alpha-Tocopherol, Beta- Carotene Cancer Prevention Study. Dietary intake was assessed at baseline by using a validated food frequency questionnaire. During a mean follow-up of 13.6 years, from 1985 through 2004,

Susanna C. Larsson; Satu Mannisto; Mikko J. Virtanen; Jukka Kontto; Demetrius Albanes; Jarmo Virtamo

2008-01-01

106

Combined dietary folate, vitamin B-12, and vitamin B-6 intake influences plasma docosahexaenoic acid concentration in rats  

PubMed Central

Background Folate, vitamin B-12, and vitamin B-6 are essential nutritional components in one-carbon metabolism and are required for methylation capacity. The availability of these vitamins may therefore modify methylation of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) by PE-N-methyltransferase (PEMT) in the liver. It has been suggested that PC synthesis by PEMT plays an important role in the transport of polyunsaturated fatty acids (PUFAs) like docosahexaenoic acid (DHA) from the liver to plasma and possibly other tissues. We hypothesized that if B-vitamin supplementation enhances PEMT activity, then supplementation could also increase the concentration of plasma levels of PUFAs such as DHA. To test this hypothesis, we determined the effect of varying the combined dietary intake of these three B-vitamins on plasma DHA concentration in rats. Methods In a first experiment, plasma DHA and plasma homocysteine concentrations were measured in rats that had consumed a B-vitamin-poor diet for 4?weeks after which they were either continued on the B-vitamin-poor diet or switched to a B-vitamin-enriched diet for another 4?weeks. In a second experiment, plasma DHA and plasma homocysteine concentrations were measured in rats after feeding them one of four diets with varying levels of B-vitamins for 4?weeks. The diets provided 0% (poor), 100% (normal), 400% (enriched), and 1600% (high) of the laboratory rodent requirements for each of the three B-vitamins. Results Plasma DHA concentration was higher in rats fed the B-vitamin-enriched diet than in rats that were continued on the B-vitamin-poor diet (P?=?0.005; experiment A). Varying dietary B-vitamin intake from deficient to supra-physiologic resulted in a non-linear dose-dependent trend for increasing plasma DHA (P?=?0.027; experiment B). Plasma DHA was lowest in rats consuming the B-vitamin-poor diet (P?>?0.05 vs. normal, P?vitamin-high diet (P??0.05 vs. enriched). B-vitamin deficiency significantly increased plasma total homocysteine but increasing intake above normal did not significantly reduce it. Nevertheless, in both experiments plasma DHA was inversely correlated with plasma total homocysteine. Conclusion These data demonstrate that dietary folate, vitamin B-12, and vitamin B-6 intake can influence plasma concentration of DHA. PMID:22647268

2012-01-01

107

Vitamin B12 deficiency presenting as pancytopenia and retinopathy in a young boy-Helicobacter pylori, a novel causative agent.  

PubMed

Deficiency of vitamin B12 (cobalamin) is a well-known cause of megaloblastic anaemia. It is a reversible cause of bone marrow failure and demyelinating nervous system disorder, hence early detection and prompt treatment of vitamin B12 deficiency is essential. After diagnosing vitamin B12 deficiency, tracking down its root cause is important in individualising the treatment approach. Helicobacter pylorirelated (H. pylori) B12 deficiency presenting as pancytopenia in pediatric age groups has been reported. However, vitamin B12 deficiency presenting as retinopathy in paediatric age groups has been rarely reported in the medical literature. We herein present the case of an adolescent male with pancytopenia and retinopathy, secondary to vitamin B12 deficiency-associated H. pylori infection. PMID:24719649

Anitha, Palaniyandi; Sasitharan, Rajendraprasad; Thambarasi, Thalavaisundaram; Krithika, Prabaharan; Mohan, Madhuvanthi; Venkataraman, Paramasivam; James, Saji; Vinoth, Ponnurangam Nagarajan

2014-01-01

108

Competitive chemiluminescent anzyme immunoassay for vitamin B12 analysis in human milk.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent discoveries of matrix interferences by haptocorrin (HC) in human milk and serum show that past analyses of vitamin B12 in samples with high HC content might have been inaccurate (Lildballe et al., 2009; Carmel & Agrawal, 2012). We evaluated two competitive enzyme-binding immunoassays for seru...

109

UTILIZATION OF DIETARY VITAMIN B12 AND COBALT ~: BY MATURE HORSES 1.2  

Microsoft Academic Search

activity per kilogram during the control period and then fed a diet that contained only 1.14 ~g of vitamin B12 activity per kilo- gram. The composition of the experimental diet is presented in table 1. Redistilled water was provided in stainless steel pails and food in aluminum trays. Both were offered ad libitum. Daily food consumption was recorded. Blood, urine

M. C. STILLIONS; S. M. TEETER; W. E. NELSON

110

An autism cohort study of cobalt levels following vitamin B12 injections  

Microsoft Academic Search

The effects of methylcobalamin (vitamin B12) injection (75 µg kg) on cobalt levels in autism spectrum disorders (ASDs) and potential toxic effects of cobalt on human neurons were evaluated. A cohort of ASDs (n = 72) presenting to the Genetic Centers of America were evaluated for the frequency of methylcobalamin injections and cobalt levels using Laboratory Corporation of America (LabCorp)

David A. Geier; Mark R. Geier

2010-01-01

111

Low Initial Vitamin B12 Levels in Helicobacter pylori-Positive Patients on Chronic Hemodialysis  

Microsoft Academic Search

Background:Helicobacter pylori has been identified as a possible cause of vitamin B12 deficiency in the general population. We assessed any potential relationship between low cyanocobalamin serum levels and Helicobacter pylori status in hemodialysis patients and subsequently correlated these results with the existence of anemia (a common complication in hemodialysis patients), and macrocytosis. Methods: In 29 chronic hemodialysis patients, active H.

H. Trimarchi; M. Forrester; J. Schropp; H. Pereyra; E. A. Freixas

2004-01-01

112

Vitamin B12 and its binding proteins in the serum of some wild game species.  

PubMed

The concentration of vitamin B12 and its binding proteins was measured in the impala, nyala, wildebeest, zebra, bushpig, warthog, and rhino, all existing in their natural state. Marked differences were found between some species. The variations observed are probably true species differences, unrelated to environmental factors. PMID:1162511

Green, R; Keep, M E; Colman, N; Metz, J

1975-01-01

113

Vitamin B12 in Obese Adolescents with Clinical Features of Insulin Resistance  

PubMed Central

Emerging evidence indicates an association between obesity, metformin use and reduced vitamin B12 status, which can have serious hematologic, neurologic and psychiatric consequences. This study aimed to examine B12 status in obese adolescents with pre-diabetes and/or clinical features of insulin resistance. Serum B12 was measured using chemiluminescence immunoassay in 103 (43 male, 60 female) obese (mean body mass index (BMI) z-score ± SD (2.36 ± 0.29)), adolescents aged 10 to 17 years, median (range) insulin sensitivity index of 1.27 (0.27 to 3.38) and 13.6% had pre-diabetes. Low B12 (<148 pmol/L) was identified in eight (7.8%) and borderline status (148 to 221 pmol/L) in an additional 25 (24.3%) adolescents. Adolescents with borderline B12 concentrations had higher BMI z-scores compared to those with normal concentrations (2.50 ± 0.22 vs. 2.32 ± 0.30, p = 0.008) or those with low B12 concentration (2.50 ± 0.22 vs. 2.27 ± 0.226, p = 0.041). In conclusion, nearly a third of obese adolescents with clinical insulin resistance had a low or borderline serum B12 status. Therefore, further investigations are warranted to explore the cause and the impact of low B12 status in obese pediatric populations. PMID:25486369

Ho, Mandy; Halim, Jocelyn H.; Gow, Megan L.; El-Haddad, Nouhad; Marzulli, Teresa; Baur, Louise A.; Cowell, Chris T.; Garnett, Sarah P.

2014-01-01

114

J. LENOIR. -NOTE SUR LA DGRADATION From the results obtained after the sur vey of vitamin B12  

E-print Network

of vitamin B12 content during the fabrication and ripening of kefir, the following conclusions can be drawn : The fabrication and ripening of Kefir involve some losses in vitamin B12. In the product being made with milk in which Kefir fungi have been added, such losses reached an average proportion of 22,09 per cent after

Paris-Sud XI, Université de

115

Vitamin B12 Deficiency and Hyperhomocysteinemia Are Partly Ameliorated by Cobalt and Nickel Supplementation in Pigs1  

Microsoft Academic Search

Vitamin B-12 deficiency and hyperhomocysteinemia alter the metabolism of trace elements. This study tested the hypothesis that there is a reverse relationship in which diets high in iron, copper, nickel and cobalt would influence vitamin B-12 deficiency outcomes including hyperhomocysteinemia. Piglets (German Landrace x Pietrain) were assigned to six groups of 8 and fed one of the following diets for

G. I. Stangl; D. A. Roth-Maier; M. Kirchgessner

116

Dietary pectin shortens the biologic half-life of vitamin B-12 in rats by increasing fecal and urinary losses  

SciTech Connect

As little as 5% of pectin added to a fiber-free diet elevates urinary methylmalonic acid (MMA) severalfold in vitamin B-12--deprived rats. The present study examines whether increased urinary MMA reflects lower vitamin B-12 status or occurs only because of fermentation of pectin by intestinal bacteria and increased production of propionate, a precursor of MMA. By monitoring urinary and fecal excretion of {sup 57}Co after a tracer dose of ({sup 57}Co)vitamin B-12, we found the biologic half-life of vitamin B-12 to be 59 d for rats fed a fiber-free diet and only 19 d for rats fed a 5% pectin diet. Also, pectin-fed rats oxidized only 12% of a 1-mmol dose of ({sup 14}C)propionate to {sup 14}CO{sub 2} in 2 h, whereas rats fed the fiber-free diet expired 33% of the dose. Finally, high urinary MMA persisted even after the removal of pectin from the diet. We conclude that dietary pectin accelerates vitamin B-12 depletion in rats, possibly by interfering with enterohepatic recycling of vitamin B-12. By stimulating microbial propionate production, pectin and other fermentable fibers may also contribute to increased urinary MMA in vitamin B-12 deficiency, but a larger propionate pool does not account for the other effects of pectin on vitamin B-12 status.

Cullen, R.W.; Oace, S.M. (Univ. of California, Berkeley (USA))

1989-08-01

117

LOW ERYTHROCYTE FOLATE, BUT NOT PLASMA VITAMIN B-12 OR HOMOCYSTEINE, IS ASSOCIATED WITH DEMENTIA IN ELDERLY LATINOS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The relationship between B vitamin status and cognitive function has been of interest for many years. There is evidence of relationships between intake and status of folate and vitamin B-12 with neurological, cognitive, and memory impairment, but results have been inconsistent. Plasma B-12, erythroc...

118

Insights into dechlorination of PCE and TCE from carbon isotope fractionation by vitamin B12  

NASA Astrophysics Data System (ADS)

Reductive dechlorination of perchloroethylene (PCE) and trichloroethylene (TCE) by vitamin B12 is both a potential remediation technique and an analogue of the microbial reductive dechlorination reaction. Stable carbon isotopic analysis, an effective and powerful tool for the investigation and monitoring of contaminant remediation, was used to characterize the isotopic effects of reductive dechlorination of PCE and TCE by vitamin B12 in laboratory microcosms. 10 mg/L vitamin B12 degraded greater than 90% of an initial concentration of PCE of 20 mg/L. TCE, the primary product of PCE degradation, accounted for between 64 - 72% of the PCE degraded. In experiments with TCE, 147 mg/L vitamin B12 degraded greater than 90% of an initial concentration of TCE of 20 mg/L. Cis-dichloroethene (cDCE), the primary product of TCE degradation, accounted for between 30 - 35% of the TCE degraded. Degradation of both PCE and TCE exhibited first order kinetics. Strong isotopic fractionation of the reactant PCE and of the reactant TCE was observed over the course of degradation. This fractionation could be described by a Rayleigh model with enrichment factors between -16.5 ppm and -15.8 ppm for PCE, and -17.2 ppm and -16.6 ppm for TCE. Fractionation was similar in all four experiments, with a mean enrichment factor of -16.5 +/- 0.6 ppm. These large enrichment factors indicate that isotopic analysis can be used to assess the occurrence of dechlorination of PCE and TCE by vitamin B12 in remediation situations. Significantly, the Rayleigh model could be used to predict the isotopic compositions of the major products of the reaction as well as the reactant, notwithstanding the lack of complete mass balance observed between product and reactant. This evidence suggests that isotopic fractionation is taking place during complexation of the chlorinated ethenes to vitamin B12, as has been suggested for reductive dechlorination by zero valent iron. The differences between e for this reaction and those observed for microbial biodegradation of the chlorinated ethenes suggest that there may be differences in the rate determining step for these two processes. Determining which steps are rate determining during degradation may allow optimization of contaminant remediation.

Slater, G.; Sherwood Lollar, B.; Lesage, S.; Brown, S.

2003-04-01

119

Competitive chemiluminescent enzyme immunoassay for vitamin B12 analysis in human milk.  

PubMed

Recent discoveries of matrix interferences by haptocorrin (HC) in human milk and serum show that past analyses of vitamin B12 in samples with high HC content might have been inaccurate (Lildballe et al., 2009; Carmel & Agrawal, 2012). We evaluated two competitive enzyme-binding immunoassays for serum/plasma (IMMULITE and SimulTRAC-SNB) for B12 analysis in human milk. B12-recovery rates (United States Environmental Protection Agency, 2007) were determined to be 78.9 ± 9.1% with IMMULITE and 225 ± 108% (range 116-553%) using SimulTRAC-SNB, most likely due to the presence of excess HC. HC-interferences were not observed with the IMMULITE assay, rendering previously reported mandatory HC-removal (Lildballe et al., 2009) unnecessary. Linearity continued at low B12-concentrations (24-193 pM; r(2)>0.985). Milk B12 concentrations from Bangladeshi women (72-959 pM) were significantly lower than those from California (154-933 pM; p<0.0001) showing IMMULITE's robustness against the complex milk matrix and its ability to measure low milk B12 concentrations. PMID:24491700

Hampel, Daniela; Shahab-Ferdows, Setareh; Domek, Joseph M; Siddiqua, Towfida; Raqib, Rubhana; Allen, Lindsay H

2014-06-15

120

Folate, Vitamin B12, and Serum Total Homocysteine Levels in Confirmed Alzheimer Disease  

Microsoft Academic Search

Background: Recent studies suggest that vascular dis- ease may contribute to the cause of Alzheimer disease (AD). Since elevated plasma total homocysteine (tHcy) level is a risk factor for vascular disease, it may also be relevant to AD. Objective: To examine the association of AD with blood levels of tHcy, and its biological determinants folate and vitamin B12. Design: Case-control

Robert Clarke; A. David Smith; Kim A. Jobst; Helga Refsum; Lesley Sutton; Per M. Ueland

1998-01-01

121

The effect of cobalt supplementation on the immune response in vitamin B 12 deficient Texel lambs  

Microsoft Academic Search

The effect of cobalt supplementation on the immune reactivity in vitamin B12 deficient lambs was measured by comparing the humoral and cell-mediated immune responses against bovine herpes virus type 1 and Mycobacterium paratuberculosis. In addition, faecal egg counts were performed after natural infection with gastrointestinal nematodes.The experiments were performed with registered Texel twin lambs of the same sex. One lamb

P. Vellema; V. P. M. G. Rutten; A. Hoek; L. Moll; G. H. Wentink

1996-01-01

122

Study on methane fermentation and production of vitamin B 12 from alcohol waste slurry  

Microsoft Academic Search

We studied biogas fermentation from alcohol waste fluid to evaluate the anaerobic digestion process and the production of\\u000a vitamin B12 as a byproduct. Anaerobic digestion using acclimated methanogens was performed using the continuously stirred tank reactor\\u000a (CSTR) and fixed-bed reactor packed with rock wool as carrier material at 55C. We also studied the effects of metal ions\\u000a added to the

Zhenya Zhang; Taisheng Quan; Pomin Li; Yansheng Zhang; Norio Sugiura; Takaaki Maekawa

2004-01-01

123

Recreational Nitrous Oxide Abuse-Induced Vitamin B12 Deficiency in a Patient Presenting with Hyperpigmentation of the Skin  

PubMed Central

Vitamin B12 deficiency causes skin hyperpigmentation, subacute combined degeneration of the spinal cord, and megaloblastic anemia. Although vitamin B12 deficiency rarely occurs in well-nourished, healthy, young people, nitrous oxide (N2O) intoxication is an important cause of vitamin B12 deficiency in this cohort. N2O, a colorless gas used as an anesthetic since the late 19th century because of its euphoric and analgesic qualities, is now used as a recreational drug and is available via the Internet and at clubs. Here, we describe the case of a 29-year-old woman presenting with skin hyperpigmentation as her only initial symptom after N2O abuse for approximately 2 years. N2O intoxication-induced vitamin B12 deficiency was diagnosed based on the skin pigmentation that had manifested over the dorsa of her fingers, toes, and trunk, coupled with myeloneuropathy of the posterior and lateral columns, a low serum vitamin B12 level, an elevated serum homocysteine level, and the N2O exposure revealed while establishing the patient's history. Symptoms improved significantly with vitamin B12 treatment. We recommend that dermatologists consider N2O intoxication-induced vitamin B12 deficiency as a potential cause of skin hyperpigmentation and myeloneuropathy of the posterior and lateral columns in young, otherwise healthy patients. Failure to recognize this presentation may result in inappropriate treatment, thus affecting patients’ clinical outcomes. PMID:23898268

Chiang, Tsung-Ta; Hung, Chih-Tsung; Wang, Wei-Ming; Lee, Jiunn-Tay; Yang, Fu-Chi

2013-01-01

124

Methylcobalamin--a form of vitamin B12 identified and characterised in Chlorella vulgaris.  

PubMed

Vitamin B12 is among the most essential biomolecules required for crucial metabolic processes in humans. Vitamin B12 was extracted from Chlorella vulgaris biomass under aqueous conditions, partially purified by passing the extract through amberlite XAD-2, Sep-Pak columns, and further purified by HPLC. The target peak eluent was subjected to characterisation by tandem mass spectrometry (MS/MS), selected ion recording (SIR) and multiple reaction monitoring (MRM) and identified as methylcobalamin (Me-Cbl). Quantification of Me-Cbl was carried out by microbiological and chemiluminescence methods, and found to be 29.87±2 ?g/100 g and 26.84±2 ?g/100 g dry weight, respectively. The presence of Me-Cbl was further substantiated using gold nanoparticle (AuNPs) based aptamer analysis, and found to be 28.02±2 ?g/100 g dry weight. Good similarity was observed among all the methods. Methylcobalamin, a form of vitamin B12 was identified in C. vulgaris and this finding enhances its use as a nutritional supplement. PMID:25306351

Kumudha, Anantharajappa; Selvakumar, Sagaya; Dilshad, Pullancheri; Vaidyanathan, Gopal; Thakur, Munna Singh; Sarada, Ravi

2015-03-01

125

Folate, vitamin B(6) , vitamin B(12) , methionine and alcohol intake in relation to ovarian cancer risk.  

PubMed

Folate, methionine, vitamin B(6) and vitamin B(12) may influence carcinogenesis due to their roles in the one-carbon metabolism pathway, which is critical for DNA synthesis, methylation and repair. Low intake of these nutrients has been associated with an increased risk of breast, colon and endometrial cancers. Previous studies that have examined the relation between these nutrients and ovarian cancer risk have been inconsistent and have had limited power to examine the relation by histologic subtype. We investigated the association between folate, methionine, vitamin B(6) , vitamin B(12) and alcohol among 1910 women with ovarian cancer and 1989 controls from a case-control study conducted in eastern Massachusetts and New Hampshire from 1992 to 2008. Diet was assessed via food frequency questionnaire. Participants were asked to recall diet one-year before diagnosis or interview. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (95% CIs). We also examined whether the associations varied by ovarian cancer histologies using polytomous logistic regression. We observed an inverse association between dietary vitamin B(6) (covariate-adjusted OR = 0.76, 95% CI 0.64-0.92; p(trend) = 0.002) and methionine intake (covariate-adjusted OR = 0.72, 95% CI = 0.60-0.87; p(trend) < 0.001) and ovarian cancer risk comparing the highest to lowest quartile. The association with dietary vitamin B(6) was strongest for serous borderline (covariate-adjusted OR = 0.49, 95% CI = 0.32-0.77; p(trend) = 0.001) and serous invasive (covariate-adjusted OR = 0.74, 95% CI = 0.58-0.94; p(trend) = 0.012) subtypes. Overall, we observed no significant association between folate and ovarian cancer risk. One-carbon metabolism related nutrients, especially vitamin B(6) and methionine, may lower ovarian cancer risk. PMID:21953625

Harris, Holly R; Cramer, Daniel W; Vitonis, Allison F; DePari, Mary; Terry, Kathryn L

2012-08-15

126

Regulation of the vitamin B12 metabolism and transport in bacteria by a conserved RNA structural element.  

PubMed

Cobalamin in the form of adenosylcobalamin (Ado-CBL) is known to repress expression of genes for vitamin B(12) biosynthesis and be transported by a posttranscriptional regulatory mechanism, which involves direct binding of Ado-CBL to 5'untranslated gene regions (5'UTR). Using comparative analysis of genes and regulatory regions, we identified a highly conserved RNA structure, the B12-element, which is widely distributed in 5'UTRs of vitamin B(12)-related genes in eubacteria. Multiple alignment of approximately 200 B12-elements from 66 bacterial genomes reveals their common secondary structure and several extended regions of sequence conservation, including the previously known B12-box motif. In analogy to the model of regulation of the riboflavin and thiamin biosynthesis, we suggest Ado-CBL-mediated regulation based on formation of alternative RNA structures including the B12-element. In Gram-negative proteobacteria, as well as in cyanobacteria, actinobacteria, and the CFB group, the cobalamin biosynthesis and vitamin B(12) transport genes are predicted to be regulated by inhibition of translation initiation, whereas in the Bacillus/Clostridium group of Gram-positive bacteria, these genes seem to be regulated by transcriptional antitermination. Phylogenetic analysis of the B12-elements reveals a large number of likely duplications of B12-elements in several bacterial genomes. These lineage-specific duplications of RNA regulatory elements seem to be a major evolutionary mechanism for expansion of the vitamin B(12) regulon. PMID:12923257

Vitreschak, Alexey G; Rodionov, Dmitry A; Mironov, Andrey A; Gelfand, Mikhail S

2003-09-01

127

Influence du cobalt et de la vitamine B12 sur la croissance et la survie des cilis du rumen in vitro,  

E-print Network

Influence du cobalt et de la vitamine B12 sur la croissance et la survie des ciliés du rumen, 94010 Créteil. Summary. lnfluence of cobalt and vitamin B12 on growth and survival of rumen ciliates of vitamin B12 was studied on the growth of rumen ciliates in the presence of normal bacterial population

Boyer, Edmond

128

A riboswitch sensor to determine vitamin B12 in fermented foods.  

PubMed

We describe a sensitive and selective method for determination of vitamin B12 content in fermented foods using riboswitch sensor. A riboswitch amplicon from Propionibacterium freudenreichii was cloned in p519NGFP vector in Escherichia coli BL21 (DE3). The expression of green fluorescence protein was revers correlated to the concentrations of adenosylcobalamin. Adenosylcobalamin directly binds to riboswitch region leading to conformational changes in the secondary structure of mRNA, thus inhibiting expression. After various examinations, a standard curve was obtained from 10 to 1000ng/mL of cyanocobalamin. The limit of determination is 10ng/mL. The inter-assay coefficients of variation were 7.5% for the range of 10-1000ng/mL. The recovery of this method was 92.3%. This method has no or less responses to nucleic acid, pseudovitamin B12, vitamin B12 bound to intrinsic factor and haptocorrin. The riboswitch sensor results were similar with HPLC, but they were Ca. 24% lower than the microbiological assay results. PMID:25577115

Zhu, Xuan; Wang, Xiaofeng; Zhang, Chen; Wang, Xiaoqi; Gu, Qing

2015-05-15

129

Effects of cobalt supplementation and vitamin B12 injections on lactation performance and metabolism of Holstein dairy cows.  

PubMed

The objective of this study was to determine lactation performance and metabolism of primiparous and multiparous dairy cows fed different levels and sources (inorganic and organic) of Co or given weekly vitamin B(12) injections. Forty-five primi- and multiparous cows at 60 d prepartum were blocked by expected calving date, and randomly assigned to 1 of 5 treatments in a randomized complete block design with treatments starting at 60 d prepartum. The 5 treatments were (1) no supplemental dietary Co (control, CON), (2) 25mg/d of supplemental dietary Co from Co carbonate (CoCarb), (3) 25mg/d of supplemental dietary Co from Co glucoheptonate (LCoGH), (4) 75 mg/d of supplemental dietary Co from Co glucoheptonate (HCoGH), and (5) CON diet plus weekly 10mg i.m. of vitamin B(12) injections (IB12). Cows remained on their respective treatment until 150 d after calving. Cobalt concentrations (mg/kg of dry matter) in the lactating diets were 1.0, 1.9, 2.3, and 5.1 for CON/IB12, CoCarb, LCoGH, and HCoGH, respectively. Dry matter intake, body weight, and body condition score were not affected by treatment. The LCoGH treatment tended to have greater milk yield than CoCarb, and CON had similar milk yields to the mean of LCoGH and HCoGH. Cobalt supplementation or the use of vitamin B(12) injections did not influence plasma or liver measures of energy metabolism. Injections of vitamin B(12) increased plasma, liver, and milk vitamin B(12) contents. Dietary Co addition did not affect plasma vitamin B(12) concentrations; however, it did increase milk vitamin B(12) concentrations throughout lactation and liver vitamin B(12) at calving with no effect of source or level of Co. Folate status of cows in the study was low and possibly limited the effect of improved vitamin B(12) status on lactation performance. Overall, Co supplementation (inorganic and organic) or vitamin B(12) injections improved measures of vitamin B(12) status, but not lactation performance compared with CON possibly due to Co being above requirements in the CON diet. PMID:23312998

Akins, M S; Bertics, S J; Socha, M T; Shaver, R D

2013-03-01

130

Production potency of folate, vitamin B(12), and thiamine by lactic acid bacteria isolated from Japanese pickles.  

PubMed

We investigated the extracellular production of folate, vitamin B(12), and thiamine in cultures of lactic acid bacteria (LAB) isolated from nukazuke, a traditional Japanese pickle, and the relationships between the vitamin production and such properties of LAB as tolerance to salts, ethanol, etc. Among the 180 isolates of LAB, two strains of Lactobacillus (Lb.) sakei and a strain of Lb. plantarum extracellularly produced high levels of folate (about 100 µg/L). A strain of Lb. coryniformis and one of Lb. plantarum produced about 2 µg/L of vitamin B(12), although the level was not high. No isolates produced a high level of thiamine. The type cultures of LBA (53 strains) did not show any higher production of these vitamins. Some isolates showed tolerance to high concentrations of salts and alcohol, and low initial pH. No significant relationships between folate or vitamin B(12) productions and these properties of LAB were apparent. PMID:23132566

Masuda, Misako; Ide, Mariko; Utsumi, Haruka; Niiro, Tae; Shimamura, Yuko; Murata, Masatsune

2012-01-01

131

Improved propionic acid and 5,6-dimethylbenzimidazole control strategy for vitamin B12 fermentation by Propionibacterium freudenreichii.  

PubMed

An efficient fermentation-strengthening approach was developed to improve the anaerobic production of vitamin B12 by cultivation process optimization with Propionibacterium freudenreichii. The effects of the byproduct propionic acid and the precursor 5,6-dimethylbenzimidazole (DMB) on vitamin B12 biosynthesis were investigated. Byproduct inhibition experiments showed that maintaining propionic acid concentration in broth below 10-20g/L in the early stage and 20-30g/L in the late stage can efficiently improve vitamin B12 biosynthesis. Batch fermentation indicated the occurrence of feed-back inhibition in intracellular intermediate biosynthesis. In addition, the incorporation of the precursor DMB depended on the fermentation level of the vitamin B12 intermediate. High vitamin B12 concentration (58.8mg/L) and production (0.37mg/g) were obtained with an expanded bed adsorption bioreactor by using the propionic acid and DMB control method. The optimum concentration and production of 59.5 and 0.59mg/L h for vitamin B12 production were respectively achieved after five continuous batches. PMID:25455014

Wang, Peng; Zhang, Zhiwei; Jiao, Youjing; Liu, Shouxin; Wang, Yunshan

2015-01-10

132

Discovery of Novel Sources of Vitamin B12 in Traditional Korean Foods from Nutritional Surveys of Centenarians  

PubMed Central

Human longevity can be explained by a variety of factors, among them, nutritional factor would play an important role. In our study of Korean centenarians for their longevity, the apparent nutritional imbalance in the traditional semi-vegetarian diet raised a special attention, especially on vitamin B12 status, supplied by animal foods. Interestingly, we found that the prevalence of vitamin B12 deficient Korean centenarians was not higher compared with those from Western nations with animal-oriented traditional foods. We assumed that there might be some unveiled sources for vitamin B12 in the Korean traditional foods. Screening of vitamin B12 contents has revealed that some traditional soybean-fermented foods, such as Doenjang and Chunggukjang, and seaweeds contain considerable amounts of vitamin B12. Taken together, it can be summarized that the traditional foods, especially of fermentation, might be evaluated for compensation of the nutritional imbalance in the vegetable-oriented dietary pattern by supplying vitamin B12, resulting in maintenance of health status. PMID:21436999

Kwak, Chung Shil; Lee, Mee Sook; Oh, Se In; Park, Sang Chul

2010-01-01

133

The Chilean flour folic acid fortification program reduces serum homocysteine levels and masks vitamin B-12 deficiency in elderly people.  

PubMed

Hyperhomocysteinemia is considered a risk factor for cardiovascular disease and is prevalent in the elderly. Supplementation with folic acid, vitamin B-6 and B-12 lowers homocysteine levels. In January 2000, the Chilean government initiated a flour folic acid fortification program to decrease the occurrence of neural tube defects. The aim of this study was to evaluate the effect of this program on serum homocysteine and folate levels in elderly subjects after 6 mo. A total of 108 elderly people were studied. We measured serum folate, homocysteine and vitamin B-12 levels before the fortification started and 6 mo later. At baseline, folate deficiency (<6.8 nmol/L) was present in 1.8%, vitamin B-12 deficiency (<165 pmol/L) in 27.6% and hyperhomocysteinemia (>14 micromol/L) in 31% of the sample. Six months later, serum folate levels increased from 16.2 +/- 6.2 to 32.7 +/- 7.1 nmol/L (P < 0.001), homocysteine levels decreased from 12.95 +/- 3.7 to 11.43 +/- 3.6 micromol/L (P < 0.001) and vitamin B-12 levels were unchanged. Flour fortification with folic acid had a moderate lowering effect on homocysteine levels. Given that vitamin B-12 deficiency was more common than folate deficiency, it may be more appropriate to add vitamin B-12 to food, at least in foods for this age group. PMID:11823592

Hirsch, Sandra; de la Maza, Pía; Barrera, Gladys; Gattás, Vivian; Petermann, Margarita; Bunout, Daniel

2002-02-01

134

Synthesis of a B ring opened 7,8-seco-vitamin B12 derivative with Grob fragmentation.  

PubMed

A synthetic route toward B ring opened 7,8-seco-cyanocobalamins is described. Hydrolysis of a novel c-lactone vitamin B12 (B12) derivative generates a cobalamin (Cbl) with a ?-bromo alcoholate subunit that reacts in situ via Grob fragmentation to the secocorrin. PMID:23991712

Oetterli, René M; Prieto, Lucas; Spingler, Bernhard; Zelder, Felix

2013-09-20

135

Simultaneous determination of vitamin B12 and its derivatives using some of multivariate calibration 1 (MVC1) techniques  

NASA Astrophysics Data System (ADS)

Resolution of binary mixtures of vitamin B12, methylcobalamin and B12 coenzyme with minimum sample pre-treatment and without analyte separation has been successfully achieved by methods of partial least squares algorithm with one dependent variable (PLS1), orthogonal signal correction/partial least squares (OSC/PLS), principal component regression (PCR) and hybrid linear analysis (HLA). Data of analysis were obtained from UV-vis spectra. The UV-vis spectra of the vitamin B12, methylcobalamin and B12 coenzyme were recorded in the same spectral conditions. The method of central composite design was used in the ranges of 10-80 mg L -1 for vitamin B12 and methylcobalamin and 20-130 mg L -1 for B12 coenzyme. The models refinement procedure and validation were performed by cross-validation. The minimum root mean square error of prediction (RMSEP) was 2.26 mg L -1 for vitamin B12 with PLS1, 1.33 mg L -1 for methylcobalamin with OSC/PLS and 3.24 mg L -1 for B12 coenzyme with HLA techniques. Figures of merit such as selectivity, sensitivity, analytical sensitivity and LOD were determined for three compounds. The procedure was successfully applied to simultaneous determination of three compounds in synthetic mixtures and in a pharmaceutical formulation.

Samadi-Maybodi, Abdolraouf; Darzi, S. K. Hassani Nejad

2008-10-01

136

Relationship of Normal Serum Vitamin B12 and Folate Levels to Cognitive Test Performance in Subtypes of Geriatric Major Depression  

Microsoft Academic Search

This retrospective study evaluated the relationships between normal serum vitamin B12 and folate levels and neuropsy chologic measures in a sample of 60 geriatric inpatients with psychotic depression, nonpsychotic depression, bipolar dis order, and dementia—all consecutively referred for cognitive testing. The psychotic depression subgroup demonstrated numerous significant positive correlations between B12 and cognitive subtests not seen in other diagnostic subgroups,

Iris R. Bell; Joel S. Edman; Joshua Miller; Nancy Hebben; Richard T. Linn; Diane Ray; Herbert L. Kayne

1990-01-01

137

Micronutrient status in female university students: iron, zinc, copper, selenium, vitamin B12 and folate.  

PubMed

Young women are at an increased risk of micronutrient deficiencies, particularly due to higher micronutrient requirements during childbearing years and multiple food group avoidances. The objective of this study was to investigate biomarkers of particular micronutrients in apparently healthy young women. Female students (n = 308; age range 18-35 year; Body Mass Index 21.5 ± 2.8 kg/m2; mean ± SD) were recruited to participate in a cross-sectional study. Blood samples were obtained from participants in the fasted state and analysed for biomarkers of iron status, vitamin B12, folate, homocysteine, selenium, zinc, and copper. The results show iron deficiency anaemia, unspecified anaemia, and hypoferritinemia in 3%, 7% and 33.9% of participants, respectively. Low vitamin B12 concentrations (<120 pmol/L) were found in 11.3% of participants, while 4.7% showed sub-clinical deficiency based on serum methylmalonic acid concentrations >0.34 ?mol/L. Folate concentrations below the reference range were observed in 1.7% (serum) or 1% (erythrocytes) of participants, and 99.7% of the participant had erythrocyte-folate concentrations >300 nmol/L. Serum zinc concentrations <10.7 ?mol/L were observed in 2% of participants. Serum copper and selenium concentrations were below the reference range in 23% and 11% of participants, respectively. Micronutrient deficiencies including iron and vitamin B12, and apparent excess of folate are present in educated Australian female students of childbearing age, including those studying nutrition. The effects of dietary behaviours and food choices on markers of micronutrient status require further investigation. PMID:25401503

Fayet-Moore, Flavia; Petocz, Peter; Samman, Samir

2014-11-01

138

Serum folate, vitamin B-12 and homocysteine and their association with depressive symptoms among US adults  

PubMed Central

Background Several nutritional and physiological factors have been linked to depression in adults including low folate and vitamin B-12 and elevated total homocysteine (tHcy) levels. Methods Nationally representative data on US adults (aged 20–85 years, n=2,524) from the National Health and Nutrition Examination Survey of the period 2005–06 were used. Depressive symptoms were measured with the Patient Health Questionnaire (PHQ) and elevated symptoms were defined as PHQ total score?10. Serum folate, vitamin B-12 and tHcy were mainly expressed as tertiles. Age, sex, race/ethnicity, education, poverty income ratio, marital status, smoking status, physical activity, body mass index and selected nutrient intakes (average of two 24-hr recalls) were considered as potential confounders. Multiple ordinary least square (OLS), logistic and zero-inflated Poisson regression models were conducted in the main analysis. Results Overall, mean PHQ score was significantly higher among women compared to men. Elevated depressive symptoms (PHQ?10) were inversely associated with folate status particularly among women [Fully adjusted odds ratio (Tertiles T3 vs. T1)=0.37 (95% CI = 0.17–0.86)], but not significantly related to tHcy or vitamin B-12. No interaction was noted between the three exposures in affecting depressive symptoms. In older adults (?50 years) and both sexes combined, total homocysteine was positively associated with elevated depressive symptoms [Fully adjusted odds ratio (Tertiles T2 vs. T1)=3.01 (95% CI = 1.01–9.03)], though no significant dose-response relationship was found. Conclusions Future interventions aiming at improving mental health outcomes among US adults should take into account dietary and other factors that would increase levels of serum folate. PMID:20841559

Beydoun, M. A.; Shroff, M. R.; Beydoun, H. A.; Zonderman, A. B.

2010-01-01

139

Reductive dechlorination of a polychlorinated biphenyl congener and hexachlorobenzene by vitamin B12.  

PubMed Central

The polychlorinated biphenyl congener 2,3,4,5,6-pentachlorobiphenyl and hexachlorobenzene were reductively dechlorinated in an aqueous biomimetic model system containing vitamin B12. The products of 2,3,4,5,6-pentachlorobiphenyl dechlorination were 2,3,5,6- and 2,3,4,6-tetrachlorobiphenyl. Hexachlorobenzene dechlorinated to pentachlorobenzene and a mixture of 1,2,4,5- and 1,2,3,5-tetrachlorobenzene. The proton from water was shown to be the source of the hydrogen atom used for the replacement of chlorine on the biphenyl ring. PMID:1575479

Assaf-Anid, N; Nies, L; Vogel, T M

1992-01-01

140

PREVALENCE OF VITAMINS E AND B12 IN DIETARY SUPPLEMENTS REPORTED IN NATIONAL HEALTH AND NUTRITION EVALUATION SURVEY (NHANES)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Objectives: Public health concerns regarding excessive Vitamin E and deficient Vitamin B12 intake warrant evaluation of total dietary intake for these nutrients. A Dietary Supplement Ingredient Database is being developed by the Nutrient Data Laboratory with the Office of Dietary Supplements and oth...

141

Low plasma vitamin B-12 in Kenyan school children is highly prevalent and improved by supplemental animal source foods  

Technology Transfer Automated Retrieval System (TEKTRAN)

The high prevalence of vitamin B-12 deficiency in many regions of the world is becoming recognized as a widespread public health problem, but it is not known to what extent this deficiency results from a low intake of the vitamin or from its malabsorption from food. In rural Kenya, where a previous ...

142

Relationship of normal serum vitamin B12 and folate levels to cognitive test performance in subtypes of geriatric major depression.  

PubMed

This retrospective study evaluated the relationships between normal serum vitamin B12 and folate levels and neuropsychologic measures in a sample of 60 geriatric inpatients with psychotic depression, nonpsychotic depression, bipolar disorder, and dementia--all consecutively referred for cognitive testing. The psychotic depression subgroup demonstrated numerous significant positive correlations between B12 and cognitive subtests not seen in other diagnostic subgroups, especially those of IQ, and verbal and visual memory. Metabolic factors including vitamin B12 may play specific roles in the cognitive dysfunctions of different geropsychiatric disorders. PMID:2206265

Bell, I R; Edman, J S; Miller, J; Hebben, N; Linn, R T; Ray, D; Kayne, H L

1990-01-01

143

Iron, folate and vitamin B12 levels in first trimester pregnancies in the Southwest region of Turkey  

PubMed Central

Objective Iron, folate and vitamin B12 play important roles in the healthy development of the fetus in pregnancy. Preconceptional levels of these micronutrients is influenced by dietary habits. The purpose of this study was to investigate the status of iron, vitamin B12 and folate in first trimester pregnancies in the southwest region of Turkey where the Mediterranean Cuisine, rich in fresh fruit and vegetables is commonly consumed. Material and Methods Two hundred and one low-middle income pregnant women were recruited during their first prenatal visit. Hemoglobin, ferritin, folate and vitamin B12 levels were evaluated and a structured questionnaire was given to gather information including age, gravida, parity, frequency of pregnancy, history of abortion, and intrauterine device usage. Based on WHO and international guidelines, anemia was defined as hemoglobin <11 g/dl, and iron deficiency as ferritin <15 ?g/L. Serum folate and vitamin B12 deficiencies were defined as levels below 3 ng/ml and 200 pg/ml respectively. Results The mean age and gestational week were 26.4±5.3 years and 9±3 weeks respectively. Mean plasma concentrations were 12.8±9.7 g/dl for hemoglobin, 22.7±17.2 ?g/L for ferritin, 12.2±5.6 ng/ml for folate and 266.6±100.2 pg/ml for vitamin B12. Anemia was detected in 4.5% of pregnant women, iron deficiency in 40.3%, vitamin B12 deficiency in 29.8% and folate deficiency in 0.5% of patients. In 10.9% of patients, both vitamin B12 and iron iron deficiency was detected. There was no significant difference for age, body mass index, gravida, parity, frequency of pregnancy, history of abortion, and intrauterine device usage between women with low and normal levels of vitamin B12 and Ferritin (p>0.05). Conclusion Iron and vitamin B12 deficiencies were relatively common in the pregnant population consuming vegetable based diets. Iron and vitamin B12 supplementation in addition to folate must be considered for the wellbeing of the fetus in pregnant women living in areas where dietary patterns are mainly vegetable based. PMID:24591983

Karabulut, Aysun; ?evket, Osman; Acun, Ayhan

2011-01-01

144

Vitamin B12[c-lactone], a biologically inactive corrinoid compound, occurs in cultured and dried lion's mane mushroom (Hericium erinaceus) fruiting bodies.  

PubMed

This study determined the vitamin B12 content of the edible medicinal mushroom Hericium erinaceus, lion's mane mushroom fruiting body, using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Trace levels (0.04-0.36 ?g/100 g dry weight) of vitamin B12 were found in most of the dried mushroom samples, and two samples contained slightly higher levels (0.56 and 1.04 ?g/100 g dry weight, respectively) of vitamin B12. We purified the corrinoid compounds from the extracts of dried lion's mane mushroom fruiting bodies using an immunoaffinity column and identified them as vitamin B12 or vitamin B12[c-lactone] (or both) based on LC/ESI-MS/MS chromatograms. This is the first report on an unnatural corrinoid, vitamin B12[c-lactone], occurring in foods. Vitamin B12[c-lactone] was simple to produce during incubation of authentic vitamin B12 and chloramine-T, an antimicrobial agent, at varying pH values (3.0-7.0) and was completely inactive in the vitamin B12-dependent bacteria that are generally used in vitamin B12 bioassays. PMID:24506286

Teng, Fei; Bito, Tomohiro; Takenaka, Shigeo; Yabuta, Yukinori; Watanabe, Fumio

2014-02-19

145

Supplementation with omega-3 fatty acids during gestation and lactation to a vitamin B12-deficient or -supplemented diet improves pregnancy outcome and metabolic variables in Wistar rats.  

PubMed

Maternal vitamin B12 deficiency leads to an adverse pregnancy outcome and increases the risk for developing diabetes and metabolic syndrome in mothers in later life. Our earlier studies have demonstrated that vitamin B12 and n-3 polyunsaturated fatty acids (PUFA) are interlinked in the one carbon cycle. The present study for the first time examines the effect of maternal n-3 PUFA supplementation to vitamin B12 deficient or supplemented diets on pregnancy outcome, fatty-acid status and metabolic variables in Wistar rats. Pregnant dams were assigned to one of the following groups: control, vitamin B12 deficient, vitamin B12 supplemented, vitamin B12 deficient + n-3 PUFA or vitamin B12 supplemented + n-3 PUFA. The amount of vitamin B12 in the supplemented group was 0.50?gkg(-1) diet and n-3 PUFA was alpha linolenic acid (ALA) 1.68, eicosapentaenoic acid 5.64, docosahexaenoic acid (DHA) 3.15 (g per 100g fatty acids per kg diet). Our findings indicate that maternal vitamin B12 supplementation did not affect the weight gain of dams during pregnancy but reduced litter size and weight and was ameliorated by n-3 PUFA supplementation. Vitamin B12 deficiency or supplementation resulted in a low percentage distribution of plasma arachidonic acid and DHA. n-3 PUFA supplementation to these diets improved the fatty-acid status. Vitamin B12 deficiency resulted in higher homocysteine and insulin levels, which were normalised by supplementation with either vitamin B12 or n-3 PUFA. Our study suggests that maternal vitamin B12 status is critical in determining pregnancy outcome and metabolic variables in dams and that supplementation with n-3 PUFA is beneficial. PMID:24355403

Khaire, Amrita; Rathod, Richa; Kemse, Nisha; Kale, Anvita; Joshi, Sadhana

2015-01-01

146

Association of methylenetetrahydrofolate reductase and methionine synthase polymorphisms with breast cancer risk and interaction with folate, vitamin B6, and vitamin B 12 intakes.  

PubMed

We assessed the association between dietary intake of folate and the MTHFR genotype with breast cancer in a Chinese population, with additional analysis of the interactions of gene polymorphisms and dietary intake of folate, vitamin B6, and vitamin B12. A case-control study was performed, and 535 patients with newly diagnosed breast cancer and 673 controls were enrolled into this study. The MTHFR 667TT genotype (odds ratio (OR)?=?1.82, 95 % confidence interval (CI)?=?1.24-2.97) and T allele (OR 0=?1.48, 95 % CI?=?1.15-1.78) were correlated with a moderately significant increased risk of breast cancer when compared with the CC genotype. Individuals carrying the MTR 2756GG genotype (OR?=?1.66, 95 % CI?=?1.16-2.56) and G allele (OR?=?1.42, 95 % CI?=?1.26-1.81) had a higher risk of breast cancer when compared with subjects with the AA genotype. The MTHFR 667 T allele and MTR 2756 G allele were associated with a higher risk of breast cancer in individuals with low folate intake, vitamin B6, and vitamin B12, but the association disappeared among subjects with moderate and high intake of folate, vitamin B6, and vitamin B12. This case-control study found that the MTHFR C677T and MTR A2756G polymorphisms are associated with risk of breast cancer, and folate, vitamin B6, and vitamin B12 intakes influence these associations. PMID:25217320

Jiang-Hua, Qiao; De-Chuang, Jiao; Zhen-Duo, Lu; Shu-de, Cui; Zhenzhen, Liu

2014-12-01

147

Supplementing lactating dairy cows with a vitamin B12 precursor, 5,6-dimethylbenzimidazole, increases the apparent ruminal synthesis of vitamin B12.  

PubMed

Cobalamin (CBL), the biologically active form of vitamin B12, and its analogs, are produced by bacteria only if cobalt supply is adequate. The analogs differ generally by the nucleotide moiety of the molecule. In CBL, 5,6-dimethylbenzimidazole (5,6-DMB) is the base in the nucleotide moiety. The present study aimed to determine if a supplement of 5,6-DMB could increase utilization of dietary cobalt for synthesis of CBL and change ruminal fermentation, nutrient digestibility, omasal flow of nutrients and ruminal protozoa counts. Eight ruminally cannulated multiparous Holstein cows (mean±standard deviation=238±21 days in milk and 736±47 kg of BW) were used in a crossover design. Cows were randomly assigned to a daily supplement of a gelatin capsule containing 1.5 g of 5,6-DMB via the rumen cannula or no supplement. Each period lasted 29 days and consisted of 21 days for treatment adaptation and 8 days for data and samples collection. Five corrinoids, CBL and four cobamides were detected in the total mixed ration and the omasal digesta from both treatments. The dietary supplement of 5,6-DMB increased (P=0.02) apparent ruminal synthesis of CBL from 14.6 to 19.6 (s.e.m. 0.8) mg/day but had no effect (P>0.1) on apparent ruminal synthesis of the four analogs. The supplement of 5,6-DMB had no effect (P>0.1) on milk production and composition, or on protozoal count, ruminal pH and concentrations of volatile fatty acids and ammonia nitrogen in rumen content. The supplement had also no effect (P>0.1) on intake, omasal flow and apparent ruminal digestibility of dry matter, organic matter, NDF, ADF and nitrogenous fractions. Plasma concentration of CBL was not affected by treatments (P=0.98). Providing a preformed part of the CBL molecule, that is, 5,6-DMB, increased by 34% the apparent ruminal synthesis of CBL by ruminal bacteria but had no effect on ruminal fermentation or protozoa count and it was not sufficient to increase plasma concentrations of the vitamin. Even though the efficiency of cobalt utilization for apparent synthesis of CBL was increased from 2.0% to 2.7% by the 5,6-DMB supplement, this improved efficiency was still very low. Further research is needed to identify the factors affecting efficiency of utilization of cobalt for synthesis of CBL by the bacterial populations in rumen. PMID:25171056

Brito, A; Chiquette, J; Stabler, S P; Allen, R H; Girard, C L

2015-01-01

148

Novel fermentation process strengthening strategy for production of propionic acid and vitamin B12 by Propionibacterium freudenreichii.  

PubMed

An efficient fermentation-strengthening approach was developed to improve the anaerobic production of propionic acid and vitamin B12 by co-fermentation with Propionibacterium freudenreichii. Vitamin B12 production from glucose resulted in relatively high productivity (0.35 mg/L h) but a low propionic acid yield (0.55 g/g). By contrast, glycerol gave a high propionic acid yield (0.63 g/g) but low productivity (0.16 g/L h). Co-fermentation of glycerol and glucose with a gradual addition strategy gave high yields (propionic acid: 0.71 g/g; vitamin B12: 0.72 mg/g) and productivities (propionic acid: 0.36 g/L h; vitamin B12: 0.36 mg/L h). Finally, the integrated feedstock and fermentation system strengthening strategy was demonstrated as an efficient method for the economic production of bio-based propionic acid and vitamin B12. PMID:25261985

Wang, Peng; Jiao, Youjing; Liu, Shouxin

2014-12-01

149

Parallel computing and first-principles calculations: Applications to complex ceramics and Vitamin B12  

NASA Astrophysics Data System (ADS)

A systematic improvement and extension of the orthogonalized linear combinations of atomic orbitals method was carried out using a combined computational and theoretical approach. For high performance parallel computing, a Beowulf class personal computer cluster was constructed. It also served as a parallel program development platform that helped us to port the programs of the method to the national supercomputer facilities. The program, received a language upgrade from Fortran 77 to Fortran 90, and a dynamic memory allocation feature. A preliminary parallel High Performance Fortran version of the program has been developed as well. To be of more benefit though, scalability improvements are needed. In order to circumvent the difficulties of the analytical force calculation in the method, we developed a geometry optimization scheme using the finite difference approximation based on the total energy calculation. The implementation of this scheme was facilitated by the powerful general utility lattice program, which offers many desired features such as multiple optimization schemes and usage of space group symmetry. So far, many ceramic oxides have been tested with the geometry optimization program. Their optimized geometries were in excellent agreement with the experimental data. For nine ceramic oxide crystals, the optimized cell parameters differ from the experimental ones within 0.5%. Moreover, the geometry optimization was recently used to predict a new phase of TiNx. The method has also been used to investigate a complex Vitamin B12-derivative, the OHCbl crystals. In order to overcome the prohibitive disk I/O demand, an on-demand version of the method was developed. Based on the electronic structure calculation of the OHCbl crystal, a partial density of states analysis and a bond order analysis were carried out. The calculated bonding of the corrin ring of OHCbl model was coincident with the big open-ring pi bond. One interesting find of the calculation was that the Co-OH bond was weak. This, together with the ongoing projects studying different Vitamin B12 derivatives, might help us to answer questions about the Co-C cleavage of the B12 coenzyme, which is involved in many important B12 enzymatic reactions.

Ouyang, Lizhi

150

Plasma vitamins B2, B6, B12, and related genetic variants as predictors of colorectal cancer risk  

PubMed Central

Background B-vitamins are essential for one-carbon metabolism and have been linked to colorectal cancer (CRC). Although associations with folate have frequently been studied, studies on other plasma vitamins B2, B6, and B12 and CRC are scarce or inconclusive. Methods Nested case-control study within the European Prospective Investigation into Cancer and Nutrition, including 1365 incident CRC cases and 2319 controls matched for study center, age, and sex. We measured the sum of B2 species riboflavin and flavin mononucleotide, and the sum of B6 species pyridoxal 5?-phosphate, pyridoxal, and 4-pyridoxic acid as indicators for vitamin B2 and B6 status, as well as vitamin B12 in plasma samples collected at baseline. In addition, we determined eight polymorphisms related to one-carbon metabolism. Relative risks (RRs) for CRC were estimated using conditional logistic regression, adjusted for smoking, education, physical activity, BMI, alcohol consumption, and intakes of fiber, red- and processed meat. Results RRs comparing highest to lowest quintile (95% confidence interval, Ptrend) were: 0.71 (0.56–0.91, 0.02) for vitamin B2, 0.68 (0.53–0.87, <0.001) for vitamin B6, and 1.02 (0.80–1.29, 0.19) for vitamin B12. The associations for vitamin B6 were stronger in males who consumed ? 30g alcohol/day. The polymorphisms were not associated with CRC. Conclusions Higher plasma concentrations of vitamins B2 and B6 are associated with a lower CRC risk. Impact This European population-based study is the first to indicate that vitamin B2 is inversely associated with CRC, and is in agreement to previously suggested inverse associations of vitamin B6 with CRC. PMID:20813848

Eussen, Simone JPM; Vollset, Stein Emil; Hustad, Steinar; Midttun, Øivind; Meyer, Klaus; Fredriksen, Åse; Ueland, Per Magne; Jenab, Mazda; Slimani, Nadia; Boffetta, Paolo; Overvad, Kim; Thorlacius-Ussing, Ole; Tjønneland, Anne; Olsen, Anja; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Morois, Sophie; Weikert, Cornelia; Pischon, Tobias; Linseisen, Jakob; Kaaks, Rudolf; Trichopoulou, Antonia; Zilis, Demosthenes; Katsoulis, Michael; Palli, Domenico; Pala, Valeria; Vineis, Paolo; Tumino, Rosario; Panico, Salvatore; Peeters, Petra HM; Bueno-de-Mesquita, H Bas; van Duijnhoven, Fränzel JB; Skeie, Guri; Muñoz, Xavier; Martínez, Carmen; Dorronsoro, Miren; Ardanaz, Eva; Navarro, Carmen; Rodríguez, Laudina; Van Guelpen, Bethany; Palmqvist, Richard; Manjer, Jonas; Ericson, Ulrika; Bingham, Sheila; Khaw, Kay-Tee; Norat, Teresa; Riboli, Elio

2010-01-01

151

CdTe quantum dot as a fluorescence probe for vitamin B(12) in dosage form.  

PubMed

We here report the CdTe quantum dot (CdTe QDs)-based sensor for probing vitamin B12 derivatives in aqueous solution. In this paper, simple and sensitive fluorescence quenching measurements has been employed. The Stern-Volmer constant (KSV), quenching rate constant (kq) and binding constant (K) were rationalized from fluorescence quenching measurement. Furthermore, the fluorescence resonance energy transfer (FRET) mechanism was discussed. This method was applicable over the concentration ranging from 1 to 14?g/mL (VB12) with correlation coefficient of 0.993. The limit of detection (LOD) of VB12 was found to be 0.15?g/mL. Moreover, the present approach opens a simple pathway for developing cost-effective, sensitive and selective QD-based fluorescence sensors/probes for biologically significant VB12 in pharmaceutical sample with mean recoveries in the range of 100-102.1%. PMID:23872019

Vaishnavi, E; Renganathan, R

2013-11-01

152

Apparent ruminal synthesis and intestinal disappearance of vitamin B12 and its analogs in dairy cows.  

PubMed

The aim of the project was to calculate the apparent synthesis or destruction of cobalamin (vitamin B(12)) and its analogs in the rumen as well as their apparent intestinal disappearance in dairy cows. Four lactating cows were fed a diet supplemented with cobalt alone (0.76 mg/kg of DM; control) or with cobalt and vitamin B(12) (cyanocobalamin, 500 mg/d; treated). In addition to cobalamin, the only biologically active molecule for the cow, 7 analogs were identified in duodenal and ileal digesta: cobinamide, which lacks the base, ribose, and phosphate groups; and 6 other molecules in which the base, 5,6-dimethylbenzimidazole, is replaced by cresol, 2-CH(3)-adenine, adenine, 2-CH(3)-S-adenine, or 5-OH-benzimidazole, or an unidentified cobamine. Small amounts of cobalamin and cobinamide were detected in the total mixed ration, but apparent synthesis of all forms took place in rumen. During the control period, cobalamin represented 38% of the total amounts of corrinoids produced in rumen. Approximately 11% of the average daily intake of cobalt was used for apparent ruminal synthesis of corrinoids, of which only 4% was incorporated into cobalamin. Only 20% of the supplement of cyanocobalamin was recovered at the duodenal level; cobinamide appeared to be the major product of degradation of supplementary cyanocobalamin in the rumen. During the control and treatment periods, there was an apparent intestinal disappearance of cobalamin and 5-OH-benzimidazole cobamide only; only the apparent intestinal disappearance of cobalamin differed between the 2 periods. Although cobalamin was not the major form synthesized by ruminal microflora and, even if supplementary cyanocobalamin was extensively destroyed by ruminal microflora, based on calculations of apparent intestinal disappearance, cobalamin seems to be the major form absorbed in the small intestine. PMID:19700714

Girard, C L; Santschi, D E; Stabler, S P; Allen, R H

2009-09-01

153

Vitamin B12 production from crude glycerol by Propionibacterium freudenreichii ssp. shermanii: optimization of medium composition through statistical experimental designs.  

PubMed

A two-step statistical experimental design was employed to optimize the medium for vitamin B(12) production from crude glycerol by Propionibacterium freudenreichii ssp. shermanii. In the first step, using Plackett-Burman design, five of 13 tested medium components (calcium pantothenate, NaH(2)PO(4)·2H(2)O, casein hydrolysate, glycerol and FeSO(4)·7H(2)O) were identified as factors having significant influence on vitamin production. In the second step, a central composite design was used to optimize levels of medium components selected in the first step. Valid statistical models describing the influence of significant factors on vitamin B(12) production were established for each optimization phase. The optimized medium provided a 93% increase in final vitamin concentration compared to the original medium. PMID:22178491

Ko?mider, Alicja; Bia?as, Wojciech; Kubiak, Piotr; Dro?d?y?ska, Agnieszka; Czaczyk, Katarzyna

2012-02-01

154

Should vitamin B12 tablets be included in more Canadian drug formularies? An economic model of the cost-saving potential from increased utilisation of oral versus intramuscular vitamin B12 maintenance therapy for Alberta seniors  

PubMed Central

Objective The aim of this study was to estimate the cost-savings attainable if all patients aged ?65 years in Alberta, Canada, currently on intramuscular therapy were switched to oral therapy, from the perspective of a provincial ministry of health. Setting Primary care setting in Alberta, Canada. Participants Seniors of age 65 years and older currently receiving intramuscular vitamin B12 therapy. Intervention Oral vitamin B12 therapy at 1000??g/day versus intramuscular therapy at 1000??g/month. Primary and secondary outcome measures Cost saving from oral therapy over intramuscular therapy, from the perspective of the Alberta Ministry of Health, including drug costs, dispensing fees, injection administration fees, additional laboratory monitoring and physician visit fees. Results Over 5?years, if all Albertans aged 65 years and older who currently receive intramuscular B12 are switched to oral therapy, our model found that $C13?975?883 can be saved. Even if no additional physician visits are billed for among patients receiving intramuscular therapy, $C8?444?346 could be saved from reduced administration costs alone. Conclusions Oral B12 therapy has been shown to be an effective therapeutic option for patients with vitamin B12 deficiency, yet only three provinces and the Non-Insured Health Benefits program include oral tablets on their formulary rather than the parenteral preparation. To ensure judicious use of limited health resources, clinicians and formulary committees are encouraged to adopt oral B12 therapy as a clinically and cost-effective first-line therapy for vitamin B12 deficiency. PMID:24793247

Houle, Sherilyn K D; Kolber, Michael R; Chuck, Anderson W

2014-01-01

155

Lactobacillus rossiae, a Vitamin B12 Producer, Represents a Metabolically Versatile Species within the Genus Lactobacillus  

PubMed Central

Lactobacillus rossiae is an obligately hetero-fermentative lactic acid bacterium, which can be isolated from a broad range of environments including sourdoughs, vegetables, fermented meat and flour, as well as the gastrointestinal tract of both humans and animals. In order to unravel distinctive genomic features of this particular species and investigate the phylogenetic positioning within the genus Lactobacillus, comparative genomics and phylogenomic approaches, followed by functional analyses were performed on L. rossiae DSM 15814T, showing how this type strain not only occupies an independent phylogenetic branch, but also possesses genomic features underscoring its biotechnological potential. This strain in fact represents one of a small number of bacteria known to encode a complete de novo biosynthetic pathway of vitamin B12 (in addition to other B vitamins such as folate and riboflavin). In addition, it possesses the capacity to utilize an extensive set of carbon sources, a characteristic that may contribute to environmental adaptation, perhaps enabling the strain's ability to populate different niches. PMID:25264826

De Angelis, Maria; Bottacini, Francesca; Fosso, Bruno; Kelleher, Philip; Calasso, Maria; Di Cagno, Raffaella; Ventura, Marco; Picardi, Ernesto; van Sinderen, Douwe; Gobbetti, Marco

2014-01-01

156

Response in Vitamin B12Production and Absorption to Increasing Cobalt Intake in the Sheep 1-2  

Microsoft Academic Search

Three sheep, fitted with intestinal reentrant and rumen cannulas, were used to estimate ruminai production of vitamin B-12 when fed diets differing in cobalt concentrations. The basal diet, which was in pelleted form, consisted of 30% ground corn, 69% ground hay and 1% sodium chloride. At daily cobalt intakes averag ing 0.047, 0.41 and 0.83 mg, mean estimates of vitamin

M. F. HEDRICH; J. M. ELLIOT; ANDJ. E. LOWE

2010-01-01

157

Investigation on the pH-dependent binding of vitamin B12 and lysozyme by fluorescence and absorbance  

NASA Astrophysics Data System (ADS)

The binding reaction between vitamin B12 (B12, cyanocobalamin) and lysozyme (Lys) has been investigated by fluorescence, synchronous fluorescence, ultraviolet-vis (UV) absorbance, and three-dimensional fluorescence. The intrinsic fluorescence of Lys was strongly quenched by the addition of B12 in different pH buffer solutions (pH 3.4, 7.4, and 9.0) and the spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of B12 ( CB12/ CLys < 5) and a combined quenching process at higher concentration of B12 ( CB12/ CLys > 5). The structural characteristics of B12 and Lys were probed, and their binding affinities were determined under different pH conditions (pH 3.4, 7.4, and 9.0). The effect of B12 on the conformation of Lys was analyzed using UV, synchronous fluorescence and three-dimensional fluorescence under different pH conditions. These results indicate that the binding of B12 to Lys causes apparent change in the secondary or tertiary structures of Lys. Furthermore, the effect of Zn 2+ on the binding constant of B12 with Lys under various pH conditions (pH 3.4, 7.4, and 9.0) was also studied.

Li, Daojin; Yang, Yumin; Cao, Xinxiang; Xu, Chen; Ji, Baoming

2012-01-01

158

Mood disorder with mixed, psychotic features due to vitamin b12 deficiency in an adolescent: case report  

PubMed Central

Vitamin B12 is one of the essential vitamins affecting various systems of the body. Reports of psychiatric disorders due to its deficiency mostly focus on middle aged and elderly patients. Here we report a case of vitamin B 12 deficiency in a 16-year old, male adolescent who presented with mixed mood disorder symptoms with psychotic features. Chief complaints were “irritability, regressive behavior, apathy, crying and truancy” which lasted for a year. Premorbid personality was unremarkable with no substance use/exposure or infections. No stressors were present. The patient was not vegetarian. Past medical history and family history was normal. Neurological examination revealed glossitis, ataxia, rigidity in both shoulders, cog-wheel rigidity in the left elbow, bilateral problems of coordination in cerebellar examination, reduced swinging of the arms and masked face. Romberg’s sign was present. Laboratory evaluations were normal. Endoscopy and biopsy revealed atrophy of the gastric mucosa with Helicobacter Pylori colonization. Schilling test was suggestive of malabsorbtion. He was diagnosed with Mood disorder with Mixed, Psychotic Features due to Vitamin B12 Deficiency and risperidone 0.5?mg/day and intramuscular vitamin B12 500 mcg/day were started along with referral for treatment of Helicobacter pylori. A visit on the second week revealed no psychotic features. Romberg’s sign was negative and cerebellar tests were normal. Extrapyramidal symptoms were reduced while Vitamin B12 levels were elevated. Risperidone was stopped and parenteral Vitamin B12 treatment was continued with monthly injections for 3?months. Follow-up endoscopy and biopsy at the first month demonstrated eradication of H. pylori. He was followed monthly for another 6?months and psychiatric symptoms did not recur at the time of last evaluation. Despite limitations, this case may underline the observation that mood disorders with psychotic features especially with accompanying extrapyramidal symptoms lacking a clear etiology may be rare manifestation of vitamin B12 and/or folate deficiency in children and adolescents and be potentially amenable to treatment. PMID:22726236

2012-01-01

159

CO2 and vitamin B12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom  

PubMed Central

Phytoplankton growth can be limited by numerous inorganic nutrients and organic growth factors. Using the subarctic diatom Attheya sp. in culture studies, we examined how the availability of vitamin B12 and carbon dioxide partial pressure (pCO2) influences growth rate, primary productivity, cellular iron (Fe), cobalt (Co), zinc (Zn) and cadmium (Cd) quotas, and the net use efficiencies (NUEs) of these bioactive trace metals (mol C fixed per mol cellular trace metal per day). Under B12-replete conditions, cells grown at high pCO2 had lower Fe, Zn and Cd quotas, and used those trace metals more efficiently in comparison with cells grown at low pCO2. At high pCO2, B12-limited cells had ?50% lower specific growth and carbon fixation rates, and used Fe ?15-fold less efficiently, and Zn and Cd ?3-fold less efficiently, in comparison with B12-replete cells. The observed higher Fe, Zn and Cd NUE under high pCO2/B12-replete conditions are consistent with predicted downregulation of carbon-concentrating mechanisms. Co quotas of B12-replete cells were ?5- to 14-fold higher in comparison with B12-limited cells, suggesting that >80% of cellular Co of B12-limited cells was likely from B12. Our results demonstrate that CO2 and vitamin B12 interactively influence growth, carbon fixation, trace metal requirements and trace metal NUE of this diatom. This suggests the need to consider complex feedback interactions between multiple environmental factors for this biogeochemically critical group of phytoplankton in the last glacial maximum as well as the current and future changing ocean. PMID:21248860

King, Andrew L; Sañudo-Wilhelmy, Sergio A; Leblanc, Karine; Hutchins, David A; Fu, Feixue

2011-01-01

160

Effect of pH on the interaction of vitamin B12 with bovine serum albumin by spectroscopic approaches.  

PubMed

The interaction mechanism between vitamin B12 (B12, cyanocobalamin) and bovine serum albumin (BSA) has been investigated by fluorescence, synchronous fluorescence, ultraviolet-vis (UV) absorbance, and three-dimensional fluorescence. The intrinsic fluorescence of BSA was strongly quenched by the addition of B12 in different pH buffer solutions (pH 2.5, 3.5, 5.0, 7.4, and 9.0) and spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of B12 (C(B12)/C(BSA)<5) and a combined quenching process at higher concentration of B12 (C(B12)/C(BSA)>5). The structural characteristics of B12 and BSA were probed, and their binding affinities were determined under different pH conditions. The results indicated that the binding abilities of B12 to BSA in the acidic and basic pH regions (pH 2.5, 3.5, 5.0, and 9.0) were lower than that at simulating physiological condition (pH 7.4). In addition, the efficiency of energy transfer from tryptophan fluorescence to B12 was found to depend on the binding distance r between the donor and acceptor calculated using Förster's theory. The effect of B12 on the conformation of BSA was analyzed using UV, synchronous fluorescence and three-dimensional fluorescence under different pH conditions. These results showed that the binding of B12 to BSA causes apparent change in the secondary and tertiary structures of BSA. PMID:21955947

Li, Daojin; Zhang, Tian; Xu, Chen; Ji, Baoming

2011-12-01

161

Influence of different dietary levels of zinc on performance, vitamin B12, and blood parameters in lambs.  

PubMed

This experiment was conducted to investigate the influence of different dietary levels of zinc (Zn) on performance, vitamin B12, and blood parameters in lambs. Thirty six cannulated Poll Dorset x Small-tailed Han wether lambs were assigned randomly to four treatment groups: The control group, which was supplemented with 0.30 mg Co/kg dry matter (DM) to the basal diet; and the low-, medium- and high-Zn supplemented groups, supplementation of 50, 100, and 150 mg Zn/kg DM to the control diet, respectively. Lambs were housed in individual pens and the experiment lasted for 70 days. There was no significant difference in body weight gain and feed/gain between different treatment groups. The high-Zn supplemented lambs showed lower vitamin B12 concentrations in both ruminal fluid and plasma, and higher methylmalonic acid and homocysteine concentrations in plasma compared with the control and low-Zn supplemented groups (p < 0.05). No significant difference was observed in these biochemical values between the control, the low-, and the medium-Zn supplemented groups (p > 0.05). Plasma folate concentration, glucose, and heme-dependent blood parameters were not influenced by dietary zinc level. It was concluded that the higher level of zinc supplementation had a negative effect on vitamin B12 in lambs. Higher inclusion level of dietary zinc could inhibit vitamin B12 synthesis in the rumen of lambs. PMID:17607954

Wang, Runlian; Zhu, Xiaoping; Guo, Fucun; Zhang, Wei; Jia, Zhihai

2006-11-01

162

Vitamin B12, Folate, Homocysteine, and Bone Health in Adults and Elderly People: A Systematic Review with Meta-Analyses  

PubMed Central

Elevated homocysteine levels and low vitamin B12 and folate levels have been associated with deteriorated bone health. This systematic literature review with dose-response meta-analyses summarizes the available scientific evidence on associations of vitamin B12, folate, and homocysteine status with fractures and bone mineral density (BMD). Twenty-seven eligible cross-sectional (n = 14) and prospective (n = 13) observational studies and one RCT were identified. Meta-analysis on four prospective studies including 7475 people showed a modest decrease in fracture risk of 4% per 50?pmol/L increase in vitamin B12 levels, which was borderline significant (RR = 0.96, 95% CI = 0.92 to 1.00). Meta-analysis of eight studies including 11511 people showed an increased fracture risk of 4% per ?mol/L increase in homocysteine concentration (RR = 1.04, 95% CI = 1.02 to 1.07). We could not draw a conclusion regarding folate levels and fracture risk, as too few studies investigated this association. Meta-analyses regarding vitamin B12, folate and homocysteine levels, and BMD were possible in female populations only and showed no associations. Results from studies regarding BMD that could not be included in the meta-analyses were not univocal. PMID:23509616

van Wijngaarden, J. P.; Doets, E. L.; Szczeci?ska, A.; Souverein, O. W.; Duffy, M. E.; Dullemeijer, C.; Cavelaars, A. E. J. M.; Pietruszka, B.; van't Veer, P.; Brzozowska, A.; Dhonukshe-Rutten, R. A. M.; de Groot, C. P. G. M.

2013-01-01

163

Cell Metabolism RBP4 Disrupts Vitamin A Uptake Homeostasis  

E-print Network

Cell Metabolism Article RBP4 Disrupts Vitamin A Uptake Homeostasis in a STRA6-Deficient Animal The cellular uptake of vitamin A from its RBP4-bound circulating form (holo-RBP4) is a homeostatic process alleviated by reducing embryonic Rbp4 levels by morpholino oligonucleotide or pharmacological treatments

Palczewski, Krzysztof

164

Folate and Vitamin B12 Transport Systems in the Developing Infant  

Technology Transfer Automated Retrieval System (TEKTRAN)

B vitamin transport systems in infants are not as well studied as those for amino acids and glucose. For most B vitamins, a 2-step process allows for digestion of coenzyme forms of the vitamins in food, followed by specific transport systems for the free vitamin in the intestine. Folate and vitamin ...

165

Nutritional value of meat: the influence of nutrition and physical activity on vitamin B12 concentrations in ruminant tissues.  

PubMed

An important nutritional characteristic of ruminant meat is its high content in vitamin B12. The variability of these contents is not known. Three studies were been set up in order to test the influence of the animal species (2 studies on Charolais steers slaughtered at 30-32 months of age, n = 24 and n = 30 and a third one on lambs slaughtered at 4.5 months of age, n = 21), of the nature of the diet (grass vs. maize silage, lucerne or concentrate diets) and of physical activity (without or with walking) on the vitamin B12 contents of different muscle types (rather oxidative (Rectus Abdominis, RA), intermediate (Longissimus Dorsi, LD), or glycolytic (Semi Tendinosus, ST)) and on the liver. The animals were supplemented in macro and trace minerals according to usual feeding practices in France in order to theoretically avoid any risk of deficiency. For this reason, cobalt allowances, which are necessary for the ruminal synthesis of vitamin B12, could differ among treatments. The results indicate the following: (1) cobalt allowances varied widely among treatments, from (sub-)deficient to plethoric allowances, influencing vitamin B12 contents of the liver, and muscles (only in case of deficiency), (2) the effects of dietary treatments or of physical exercise were essentially related to differences in cobalt allowances, (3) the oxidative type muscle (RA) showed contents which were double those in glycolytic type muscle (RA 10.8 vs. ST 5.0 ng.g(-1)) and (4) vitamin B12 contents of raw muscles were lower than the values indicated in tables of feed composition for humans for cooked meat (0.5 to 1 vs. 2 to 3 microg.100 g(-1)). PMID:16045893

Ortigues-Marty, Isabelle; Micol, Didier; Prache, Sophie; Dozias, Dominique; Girard, Christiane L

2005-01-01

166

Response to Quinlivan: Post-fortification, folate intake in vitamin B12 deficiency is positively related to homocysteine and methylmalonic acid  

Technology Transfer Automated Retrieval System (TEKTRAN)

With cross-sectional data, causes and effects are difficult to distinguish, and Quinlivan suggests that high circulating concentrations of homcysteine (Hcy), methylmalonic acid (MMA), and folate observed among vitamin B12-deficient survey participants all resulted from a lack of vitamin B12 (1). How...

167

Vitamin B-12 and folate status in relation to decline in scores on the Mini-Mental State Examination in the Framingham Heart Study  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biochemical evidence of low vitamin B-12 status is common in seniors, but its clinical relevance is unclear. Vitamin B-12 deficiency can result in rapid, irreversible cognitive decline – a phenomenon that has been linked to high folate status. Our objective was to investigate the cognitive significa...

168

Severe vitamin B12 deficiency with pancytopenia, hepatosplenomegaly and leukoerythroblastosis in two Syrian refugee infants: a challenge to differentiate from acute leukaemia.  

PubMed

Megaloblastic anaemia due to vitamin B12 deficiency is rare in childhood. However, as most cases are due to maternal insufficiency, it is mainly seen in breastfed infants especially when the mother's socioeconomic status is low and the nutrition is not adequate. We present case of two Syrian refugee infants with severe vitamin B12 deficiency with pancytopenia, hepatosplenomegaly and leukoerythroblastosis. PMID:24599434

Belen, Burcu; Hismi, Burcu Ozturk; Kocak, Ulker

2014-01-01

169

Water structure in vitamin B12 coenzyme crystals. II. Structural characteristics of the solvent networks.  

PubMed Central

The geometrical details of the solvent structure in vitamin B12 coenzyme crystals with respect to hydrogen bonding and nonbonded contacts, are described. The individual H-bond geometries varied over wide ranges, similar to those observed in small molecule structures. Large deviations from tetrahedral coordination were found around a majority of the waters. The mutual positions and orientations of the water molecules could not be adequately explained in terms of the H-bonding relationships present in the structure. However, additional investigations, which focused on the short range nonbonded contacts around water positions in a variety of crystal hydrates, revealed several structural regularities (Savage, 1986b). These features relate to the nonbonded O...O, H...O, and H...H interactions, and give rise to a set of repulsive restrictions that are seen to be very much stronger stereochemical restraints than those associated with H-bonding. The short-range restrictions appear largely to govern the local orientational correlations and packing arrangements of the water structure within the coenzyme (and other hydrate) crystals. In more general terms, the inclusion of the nonbonding relationships as well as the attractive H-bonding interactions, leads to a significant increase in our understanding of water structure(s). The repulsive restrictions can be used as stereochemical restraints in the interpretation and refinement of solvent structures within larger hydrate systems, such as protein crystals. They may also be included in potential functions used to simulate solvent structures in aqueous solutions and hydrate systems. PMID:3790697

Savage, H

1986-01-01

170

Biosynthesis of vitamin B12: structure of precorrin-6x octamethyl ester.  

PubMed Central

13C-labeled precorrin-6x is biosynthesized by cell-free protein preparations from Pseudomonas denitrificans in separate experiments using delta-amino[5-13C]levulinic acid and the corresponding delta-amino[4-13C]- and delta-amino[3-13C]levulinic acid-labeled forms in conjunction with S-[methyl-13C]adenosylmethionine for the latter two experiments. These labeled precorrin-6x samples, as their octamethyl esters, are studied by a range of NMR techniques. In addition, nuclear Overhauser effect difference measurements are made on unlabeled precorrin-6x ester to determine connectivities. The structure 6a so established for precorrin-6x ester (i) confirms the results reported in the preceding paper that precorrin-6x has a ring-contracted macrocycle, still carries the C-12 acetate residue, and stands at the oxidation level of a dehydrocorrin; (ii) reveals the unexpected methylation at C-11 not C-12, leading to a structure with separated chromophores; and (iii) implies that methyl migration from C-11 to C-12 occurs when precorrin-6x is converted into hydrogenobyrinic acid. Proposals for the biosynthesis of the corrin macrocycle of hydrogenobyrinic acid and vitamin B12 are made. PMID:2247450

Thibaut, D; Blanche, F; Debussche, L; Leeper, F J; Battersby, A R

1990-01-01

171

Dietary cobalt can promote gastrointestinal bacterial production of vitamin B 12 in sufficient amounts to supply growth requirements of grouper, Epinephelus malabaricus  

Microsoft Academic Search

Two growth trials were conducted to elucidate the dietary essentiality of cobalt (Co) and vitamin B12 for grouper, Epinephelus malabaricus. In Exp. 1, a vitamin B12-free basal diet was supplemented with 0.05, 6.5, 10.7, 20.7, 41.6, 82.7 and 153.1mgCo\\/kg; in Exp. 2, a vitamin B12-free basal diet with 10mgCo\\/kg was supplemented with 0, 8.3, 18.1, 54.0, 87.1 and 193.2?gB12\\/kg diet,

Yu-Hung Lin; Jing-Yun Wu; Shi-Yen Shiau

2010-01-01

172

The effect of Helicobacter pylori on vitamin B 12 blood levels in chronic renal failure patients: a single blind control trial.  

PubMed

Helicobacter pylori (HP) is a common infection worldwide and has been associated with severe morbidity. The level of vitamin B 12 in HP-infected chronic kidney disease (CKD) patients is reported to be lower than in the general population. The present study has been designed to evaluate the vitamin B 12 level in HP-infected CKD patients. We assessed the serum levels of vitamin B 12 in 50 CKD patients with positive HP serology, one and three months after the eradication of HP infection. There were significant differences between the serum levels of vitamin B 12 in the study patients before (806.98 ± 466.82) and after (760.36 ± 433.93) eradication treatment (P <0.001). We conclude that our study suggests the correlation between vitamin B 12 deficiency in CKD patients and the HP infection status. PMID:23816726

Khedmat, Hossein; Amini, Mohsen; Karbasi, Ashraf; Azizi, Reza

2013-07-01

173

Effect of pH on the interaction of vitamin B12 with bovine serum albumin by spectroscopic approaches  

NASA Astrophysics Data System (ADS)

The interaction mechanism between vitamin B12 (B12, cyanocobalamin) and bovine serum albumin (BSA) has been investigated by fluorescence, synchronous fluorescence, ultraviolet-vis (UV) absorbance, and three-dimensional fluorescence. The intrinsic fluorescence of BSA was strongly quenched by the addition of B12 in different pH buffer solutions (pH 2.5, 3.5, 5.0, 7.4, and 9.0) and spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of B12 ( CB12/ CBSA < 5) and a combined quenching process at higher concentration of B12 ( CB12/ CBSA > 5). The structural characteristics of B12 and BSA were probed, and their binding affinities were determined under different pH conditions. The results indicated that the binding abilities of B12 to BSA in the acidic and basic pH regions (pH 2.5, 3.5, 5.0, and 9.0) were lower than that at simulating physiological condition (pH 7.4). In addition, the efficiency of energy transfer from tryptophan fluorescence to B12 was found to depend on the binding distance r between the donor and acceptor calculated using Förster's theory. The effect of B12 on the conformation of BSA was analyzed using UV, synchronous fluorescence and three-dimensional fluorescence under different pH conditions. These results showed that the binding of B12 to BSA causes apparent change in the secondary and tertiary structures of BSA.

Li, Daojin; Zhang, Tian; Xu, Chen; Ji, Baoming

2011-12-01

174

Effects of folic acid and vitamin B12 supplementation on culling rate, diseases, and reproduction in commercial dairy herds.  

PubMed

This study was undertaken to determine the effect of a combined folic acid and vitamin B12 supplement given in early lactation on culling rate, metabolic disorders and other diseases, and reproduction in commercial dairy herds. A total of 805 cows (271 primiparous and 534 multiparous cows) in 15 commercial dairy herds were involved. Every 2mo from February to December 2010 and within each herd, cows were assigned according to parity, previous 305-d milk production, and calving interval to 5mL of either (1) saline 0.9% NaCl (control group) or (2) 320mg of folic acid + 10mg of vitamin B12 (vitamin group). Treatments were administered weekly by intramuscular injections starting 3wk before the expected calving date until 8wk after parturition. A total of 221 cows were culled before the next dry period. Culling rate was not affected by treatment and was 27.5%; culling rate was greater for multiparous (32.2%) than for primiparous cows (18.8%). Within the first 60d in milk (DIM), 47 cows were culled, representing 21.3% of total culling, and no treatment effect was noted. Ketosis incidence based on a threshold ?100µmol/L of ?-hydroxybutyrate in milk was 38.3±2.9% for the vitamin group and 41.8±3.0% for the control group and was not affected by treatment. The combined supplement of folic acid and vitamin B12 did not decrease incidence of retained placenta, displaced abomasum, milk fever, metritis, or mastitis. However, the incidence of dystocia decreased by 50% in multiparous cows receiving the vitamin supplement, although no effect was observed in primiparous cows. The first breeding postpartum for multiparous cows occurred 3.8d earlier with the vitamin supplement compared with controls, whereas no treatment effect was seen for primiparous cows. Days open, first- and second-breeding conception rates, number of breedings per conception, and percentage of cows pregnant at 150 DIM were not affected by treatment. The reduced percentage of dystocia combined with the earlier DIM at first breeding for multiparous cows receiving the combined supplementation in folic acid and vitamin B12 indicates that the vitamin supplement had a positive effect in older cows. PMID:24485680

Duplessis, M; Girard, C L; Santschi, D E; Laforest, J-P; Durocher, J; Pellerin, D

2014-04-01

175

Combined Vitamins B12b and C Induce the Glutathione Depletion and the Death of Epidermoid Human Larynx Carcinoma Cells HEp2  

Microsoft Academic Search

The combination of hydroxocobalamin (vitamin B12b) and ascorbicacid (vitamin C) can cause the death of tumor cells at the concentrationsof the components at which they are nontoxic when administeredseparately. This cytotoxic action on epidermoid human larynx carcinomacells HEp-2 in vitro is shown to be due to the hydrogen peroxidegenerated by the combination of vitamins B12b and C. The drop inthe

Vladimir S. Akatov; Yury V. Evtodienko; Violetta V. Leshchenko; Vera V. Teplova; Margarita M. Potselueva; Alexey G. Kruglov; Enric I. Lezhnev; Raisa I. Yakubovskaya

2000-01-01

176

Genome-wide association study identifies novel loci associated with serum level of vitamin B12 in Chinese men.  

PubMed

Vitamin B12 (VitB12 or cobalamin) is an essential cofactor in several metabolic pathways. Clinically, VitB12 deficiency is associated with pernicious anemia, neurodegenerative disorder, cardiovascular disease and gastrointestinal disease. Although previous genome-wide association studies (GWAS) identified several genes, including FUT2, CUBN, TCN1 and MUT, that may influence VitB12 levels in European populations, common genetic determinants of VitB12 remain largely unknown, especially in Asian populations. Here we performed a GWAS in 1999 healthy Chinese men and replicated the top findings in an independent Chinese sample with 1496 subjects. We identified four novel genomic loci that were significantly associated with serum level of VitB12 at a genome-wide significance level of 5.00 × 10(-8). These four loci were MS4A3 (11q12.1; rs2298585; P= 2.64 × 10(-15)), CLYBL (13q32; rs41281112; P= 9.23 × 10(-10)), FUT6 (19p13.3; rs3760776; P= 3.68 × 10(-13)) and 5q32 region (rs10515552; P= 3.94 × 10(-8)). In addition, we also confirmed the association with the serum level of VitB12 for the previously reported FUT2 gene and identified one novel non-synonymous single-nucleotide polymorphism in FUT2 gene in this Chinese population (19q13.33; rs1047781; P= 3.62 × 10(-36)). The new loci identified offer new insights into the biochemical pathways involved in determining the serum level of VitB12 and provide opportunities to better delineate the role of VitB12 in health and disease. PMID:22367966

Lin, Xiaoling; Lu, Daru; Gao, Yong; Tao, Sha; Yang, Xiaobo; Feng, Junjie; Tan, Aihua; Zhang, Haiying; Hu, Yanling; Qin, Xue; Kim, Seong-Tae; Peng, Tao; Li, Li; Mo, Linjian; Zhang, Shijun; Trent, Jeffrey M; Mo, Zengnan; Zheng, S Lilly; Xu, Jianfeng; Sun, Jielin

2012-06-01

177

The role of metformin on vitamin B12 deficiency: a meta-analysis review.  

PubMed

Metformin is the only biguanide oral hypoglycemic drug, that is used to treat patients with type-2 diabetes mellitus. There are some reports of metformin being associated with decreased serum levels of vitamin B12 (VB12). The objective of this study is to systematically analyze the impact of metformin on the frequency of VB12 deficiency and serum levels of VB12. A search of various databases provided 18 retrospective cohort studies and 11 randomized controlled trials. Pooled estimates of odds ratio with 95 % confidence interval using random effect model were conducted. Studies were examined for heterogeneity, publication bias and sensitivity analysis. Separate analysis of randomized control trials (RCTs) including both low-risk and high-risk bias was also conducted. 29 studies were selected with a total of 8,089 patients. 19 studies were rated intermediate or high quality. Primary outcome suggested increased incidence of VB12 deficiency in metformin group (OR = 2.45, 95 % CI 1.74-3.44, P < 0.0001.) Heterogeneity was relatively high (I (2) = 53 %), with minor publication bias. Secondary outcome suggested lower serum VB12 concentrations in metformin group (Mean difference = -65.8, 95 % CI -78.1 to -53.6 pmol/L, P < 0.00001) with high heterogeneity (I (2) = 98 %,) and low publication bias. RCTs analysis of low-and high-risk group revealed similar trends. We conclude that metformin treatment is significantly associated with an increase in incidence of VB12 deficiency and reduced serum VB12 levels. PMID:25502588

Niafar, Mitra; Hai, Faizi; Porhomayon, Jahan; Nader, Nader Djalal

2015-02-01

178

Role of vitamin B12 on methylmalonyl-CoA mutase activity.  

PubMed

Vitamin B(12) is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods. PMID:22661206

Takahashi-Iñiguez, Tóshiko; García-Hernandez, Enrique; Arreguín-Espinosa, Roberto; Flores, María Elena

2012-06-01

179

Elevated Serum Vitamin B12 Levels in Association With Tumor Markers as the Prognostic Factors Predictive for Poor Survival in Patients With Hepatocellular Carcinoma  

Microsoft Academic Search

Elevated blood vitamin B12 (VitB12) level has recently been identified as a prognostic indicator for advanced cancer patients. The predictive value of blood VitB12 for survival of patients with hepatocellular carcinoma (HCC) remains unclear. Our objective was to examine the determinants of elevated serum VitB12 levels and their associations with prognosis of patients with HCC. The cohort study included 90

Ching-Yih Lin; Chang-Sheng Kuo; Chin-Li Lu; Meng-Ying Wu; Rwei-Fen Syu Huang

2010-01-01

180

Effects of vitamin B 12 on bright light on cognitive and sleep-wake rhythm in Alzheimer-type dementia  

Microsoft Academic Search

The present study investigated the effects of vitamin B12 (VB12) on circadian rhythm in Alzheimer-type dementia (ATD). Twenty-eight ATD patients were treated with bright light therapy (BLT) for 8 weeks. For the latter 4 weeks, half were treated with VB12 with BLT (BLT + VB12). We evaluated the cognitive state with Mini-Mental State Examination and the circadian rhythm with actigraphy

Takao Ito; Hiroshi Yamadera; Ritsuko Ito; Hideaki Suzuki; Kentaro Asayama; Shunkichi Endo

2001-01-01

181

Homocysteine and vitamin B12 status and iron deficiency anemia in female university students from Gaza Strip, Palestine  

PubMed Central

Objective Nutritional deficiencies are very significant to the overall health of humans at all ages and for both genders, yet in infants, children and women of childbearing age these deficiencies can seriously affect growth and development. The present work is aimed to assess homocysteine and vitamin B12 status in females with iron deficiency anemia from the Gaza Strip. Methods Venous blood samples were randomly collected from 240 female university students (18–22 years old) and parameters of the complete blood count, serum ferritin, homocysteine and vitamin B12 were measured. Statistical analysis included the t-test and analysis of variance (ANOVA) using the IBM SPSS software (version 18). Statistical significance was set for p-values <0.05. Results The results revealed that 20.4% of the students have iron deficiency anemia. The mean serum vitamin B12 level in females with iron deficiency anemia (212.9 ± 62.8 pg/mL) was significantly lower than in normal controls (286.9 ± 57.1 pg/mL) and subjects with microcytic anemia and normal ferritin (256.7 ± 71.1 pg/mL). Significantly higher serum homocysteine levels were reported in the iron deficiency anemia group (27.0 ± 4.6 ?mol/L) compared to normal controls (15.5 ± 2.9 ?mol/L) and in subjects with microcytic anemia and normal ferritin (18.1 ± 2.7 ?mol/L). Statistically significant negative correlations were reported for serum homocysteine with serum ferritin, vitamin B12, hemoglobin, and hematocrit levels. Conclusion Important associations were found between serum homocysteine and markers of iron deficiency. Monitoring homocysteine levels might be essential to understand the development of different clinical conditions including anemia. It seems necessary to conduct prospective trials to determine whether treating anemia ameliorates homocysteine levels. PMID:25031061

Sirdah, Mahmoud Mohammed; Yassin, Maged M.; El Shekhi, Sabreen; Lubbad, Abdel Monem

2014-01-01

182

Influence of Different Ratios of Cobalt and Copper Supplementation on Vitamin B 12 Status and Nutrient Utilization in Sheep  

Microsoft Academic Search

The present study is aimed to investigate the effects of different ratios of cobalt (Co) and copper (Cu) supplementation on vitamin B12 status and nutrient utilization in sheep. Twenty wether lambs with an average weight (22.9 ± 0.8) kg were randomly divided into five groups and fed with the control diet which was supplied with 0.3 mg kg-1 DM (dry

Run-lian WANG; Wei ZHANG; Xiao-ping ZHU; Zhi-hai JIA

2010-01-01

183

Continuous methane fermentation and the production of vitamin B 12 in a fixed-bed reactor packed with loofah  

Microsoft Academic Search

A fixed-bed reactor with acclimated methanogens immobilized on a loofah support was studied on a laboratory scale to evaluate the system producing methane from the mixture of CO2 and H2 gas, with the production of vitamin B12 as a by-product. Fermentation using CO2\\/H2 acclimated methanogens was conducted in a jar fermentor with hydraulic retention times (HRTs) of three and six

Yingnan Yang; Zhenya Zhang; Jun Lu; Takaaki Maekawa

2004-01-01

184

Comparative analysis of serum homocysteine, folic acid and Vitamin B 12 levels in patients with noise-induced hearing loss  

Microsoft Academic Search

Objective: The aim of the present study was to determine the levels of homocysteine, folic acid, and Vitamin B12 in subjects with noise-induced hearing loss. Furthermore, possible links between these parameters and noise-induced hearing loss were aimed to be evaluated. Methods: In the present study, blood samples were obtained from all subjects after overnight fasting for biochemical analysis. We examined

Uzeyir Gok; Ihsan Halifeoglu; Halit Canatan; Mucahit Yildiz; M. Ferit Gursu; Biray Gur

2004-01-01

185

Hypomethylation of Serum Blood Clot DNA, but Not Plasma EDTA-Blood Cell Pellet DNA, from Vitamin B12-Deficient Subjects  

PubMed Central

Vitamin B12, a co-factor in methyl-group transfer, is important in maintaining DNA (deoxycytidine) methylation. Using two independent assays we examined the effect of vitamin B12-deficiency (plasma vitamin B12<148 pmol/L) on DNA methylation in women of childbearing age. Coagulated blood clot DNA from vitamin B12-deficient women had significantly (p<0.001) lower percentage deoxycytidine methylation (3.23±0.66%; n?=?248) and greater [3 H]methyl-acceptance (42,859±9,699 cpm; n?=?17) than DNA from B12-replete women (4.44±0.18%; n?=?128 and 26,049±2,814 cpm; n?=?11) [correlation between assays: r?=?–0.8538; p<0.001; n?=?28]. In contrast, uncoagulated EDTA-blood cell pellet DNA from vitamin B12-deficient and B12-replete women exhibited similar percentage methylation (4.45±0.15%; n?=?77 vs. 4.47±0.15%; n?=?47) and [3 H]methyl-acceptance (27,378±4,094 cpm; n?=?17 vs. 26,610±2,292 cpm; n?=?11). Therefore, in simultaneously collected paired blood samples, vitamin B12-deficiency was associated with decreased DNA methylation only in coagulated samples. These findings highlight the importance of sample collection methods in epigenetic studies, and the potential impact biological processes can have on DNA methylation during collection. PMID:23785415

Zhu, Jiang-Hui; Maneval, David R.; Hao, Ling; Li, Zhu; Rasmussen, Sonja A.; Berry, R. J.; Bailey, Lynn B.

2013-01-01

186

Hypomethylation of serum blood clot DNA, but not plasma EDTA-blood cell pellet DNA, from vitamin B12-deficient subjects.  

PubMed

Vitamin B12, a co-factor in methyl-group transfer, is important in maintaining DNA (deoxycytidine) methylation. Using two independent assays we examined the effect of vitamin B12-deficiency (plasma vitamin B12<148 pmol/L) on DNA methylation in women of childbearing age. Coagulated blood clot DNA from vitamin B12-deficient women had significantly (p<0.001) lower percentage deoxycytidine methylation (3.23±0.66%; n?=?248) and greater [3 H]methyl-acceptance (42,859±9,699 cpm; n?=?17) than DNA from B12-replete women (4.44±0.18%; n?=?128 and 26,049±2,814 cpm; n?=?11) [correlation between assays: r?=?-0.8538; p<0.001; n?=?28]. In contrast, uncoagulated EDTA-blood cell pellet DNA from vitamin B12-deficient and B12-replete women exhibited similar percentage methylation (4.45±0.15%; n?=?77 vs. 4.47±0.15%; n?=?47) and [3 H]methyl-acceptance (27,378±4,094 cpm; n?=?17 vs. 26,610±2,292 cpm; n?=?11). Therefore, in simultaneously collected paired blood samples, vitamin B12-deficiency was associated with decreased DNA methylation only in coagulated samples. These findings highlight the importance of sample collection methods in epigenetic studies, and the potential impact biological processes can have on DNA methylation during collection. PMID:23785415

Quinlivan, Eoin P; Crider, Krista S; Zhu, Jiang-Hui; Maneval, David R; Hao, Ling; Li, Zhu; Rasmussen, Sonja A; Berry, R J; Bailey, Lynn B

2013-01-01

187

Insights into the Evolution of Vitamin B12 Auxotrophy from Sequenced Algal Genomes  

E-print Network

over 20% require vitamin B1 (thiamine) and a smaller proportion (5%) require biotin (vitamin B7) (Croft. 2005). Biotin and thiamine auxotrophy are the result of the loss of one or more of the biosynthetic

Goldstein, Raymond E.

188

The effects of vitamin B12 and diclofenac and their combination on cold and mechanical allodynia in a neuropathic pain model in rats  

PubMed Central

The present study was performed to investigate the effects of long-term intraperitoneal (IP) injection of vitamin B12 and diclofenac in separate and combined treatments on cold and mechanical allodynia in a neuropathic pain model in rats. Neuropathic pain was induced by crush injury in right tibial nerve. Acetone spray and von Frey tests were used to obtain cold and mechanical allodynia responses, respectively, on day 11 after nerve crush. Normal saline, vitamin B12 and diclofenac were injected intraperitoneally for 10 consecutive days after surgery. Normal saline treated rats showed cold and mechanical allodynia responses after nerve crush. Vitamin B12 at doses of 50, 100 and 200 µg kg-1 and diclofenac at a dose of 2 mg kg-1 produced antiallodynic effects. Antiallodynic effects were not observed when subanalgesic doses of vitamin B12 (25 µg kg-1) and diclofenac (0.25 mg kg-1) were used together. By increasing the dose of vitamin B12 to an effective dose (100 µg kg-1), antiallodynic effects were observed when compared with diclofenac (0.25 mg kg-1) alone. The results indicated that vitamin B12 and diclofenac produced neuropathic pain suppressing effects. Moreover, a potentiation effect was observed between vitamin B12 and diclofenac.

Tamaddonfard, Esmaeal; Samadi, Farzad; Egdami, Karim

2013-01-01

189

Relation between vitamin B12 and folate status, and hemoglobin concentration and parasitemia during acute malaria infections in Colombia.  

PubMed

Anemia is a common complication of human malaria. Since micronutrient deficiencies are highly prevalent in malaria-endemic areas and appear to contribute to anemia etiology, we conducted a cross-sectional study in Tumaco, Colombia, to examine the associations between plasma vitamin B12 or erythrocyte folate concentrations and hemoglobin (Hb) among 96 adults with predominantly Plasmodium falciparum malaria. Prevalence of folate and vitamin B12 deficiencies was 26.0 and 26.6%, respectively. There was an inverse, linear relation between folate and Hb concentrations. Adjusted difference in Hb between lowest and highest folate quartiles was 1g/dL (p=0.04; p, test for trend=0.01). Vitamin B12 was not associated with Hb concentrations and did not modify the associations between folate and Hb. Incidentally, body mass index (BMI) was inversely associated with parasitemia and risk of clinical malaria. Future longitudinal studies are warranted to determine the potential pathophysiological role of folate in malaria-related anemia. PMID:19931503

Caicedo, Olga; Villamor, Eduardo; Forero, Yibby; Ziade, José; Pérez, Pilar; Quiñones, Francisco; Arévalo-Herrera, Myriam; Herrera, Sócrates

2010-04-01

190

Relation between Vitamin B12 and Folate Status, and Hemoglobin Concentration and Parasitemia during Acute Malaria Infections in Colombia  

PubMed Central

Anemia is a common complication of human malaria. Since micronutrient deficiencies are highly prevalent in malaria-endemic areas and appear to contribute to anemia etiology, we conducted a cross-sectional study in Tumaco, Colombia, to examine the associations between plasma vitamin B12 or erythrocyte folate concentrations and hemoglobin (Hb) among 96 adults with predominantly Plasmodium falciparum malaria. Prevalence of folate and vitamin B12 deficiencies were 26.0% and 26.6%, respectively. There was an inverse, linear relation between folate and Hb concentrations. Adjusted difference in Hb between lowest and highest folate quartiles was 1 g/dL (p = 0.04; p, test for trend = 0.01). Vitamin B12 was not associated with Hb concentrations and did not modify the associations between folate and Hb. Incidentally, body mass index (BMI) was inversely associated with parasitemia and risk of clinical malaria. Future longitudinal studies are warranted to determine the potential pathophysiological role of folate in malaria-related anemia. PMID:19931503

Caicedo, Olga; Villamor, Eduardo; Forero, Yibby; Ziade, José; Pérez, Pilar; Quiñones, Francisco; Arévalo-Herrera, Myriam; Herrera, Sócrates

2010-01-01

191

Serious adverse drug reaction in a woman with hyperemesis gravidarum after first exposure to vitamin B complex containing vitamins B1, B6 and B12.  

PubMed

We report the case of a pregnant woman who suffered from hypotension after first exposure to intravenous administration of a combination drug containing vitamins B1, B6 and B12 (Vitamedin; Daiichi-Sankyo, Tokyo, Japan). A 27-year-old Japanese woman received an intravenous infusion of fluid containing a vitamin B complex due to hyperemesis gravidarum. Thirty minutes after the start of infusion she was found to be in hypotension. The patient had stupor, general sweating, blood pressure of 82/50 mmHg, and low percutaneous oxygen saturation (SpO(2)) of 88%. We immediately stopped the infusion, lifted her legs and administered oxygen. Three minutes after these treatments, she quickly recovered to a good general condition. A skin prick test for vitamin B12 was positive, but tests for B1, B6, mannitol and saline were negative, indicating this adverse reaction was one of drug hypersensitivity due to the vitamin B12 in Vitamedin. Patients should be observed carefully immediately after the administration of Vitamedin. PMID:19751344

Kuwata, Yoshimine; Tsuruoka, Shuichi; Ohkuchi, Akihide; Matsubara, Shigeki; Izumi, Akio; Suzuki, Mitsuaki

2009-08-01

192

Effects of cobalt/vitamin B12 status in ewes on ovum development and lamb viability at birth.  

PubMed

Scottish Blackface ewes from cobalt-deficient farmland were fed a diet containing 0.06 mg cobalt per kg dry matter from approximately 30 days before embryo recovery/transfer until lambing. Ewes remained untreated (-Co; n = 82) or were given an intraruminal cobalt-containing bolus to compensate for the dietary deficit (+Co; n = 82). Ewes used as embryo donors (-Co, n = 17; +Co, n = 16) were artificially inseminated with semen from a single Suffolk sire. Day 6 embryos obtained from -Co and +Co donors were transferred in singleton to -Co and +Co recipients in a 2 x 2 factorial-designed experiment to determine the effects of cobalt/vitamin B12 status during the periconception period (factor 1) and pregnancy (factor 2) on lamb viability at birth. Mean (+/- s.e.m.) circulating concentrations of vitamin B12 in -Co and +Co donors at ovum recovery were 182 +/- 10 and 1288 +/- 64 pmol L(-1), respectively (P < 0.001), and the number of corpora lutea per ewe ovulating was 9.9 +/- 1.6 and 14.4 +/- 1.3, respectively (P < 0.05). Treatment did not affect the proportion of recovered ova that contained >32 cells (viable) or the median stage of development (late morula), but viable ova recovered from -Co v. +Co ewes had a better morphological grade (2.0 +/- 0.1 v. 2.20 +/- 0.04, respectively; P < 0.01). There was no effect of treatment on the proportion of recipient ewes that became pregnant. Circulating concentrations of vitamin B12 were lower in -Co than +Co ewes during pregnancy (P < 0.001) and at birth in lambs born to -Co ewes compared with those born to +Co ewes (P < 0.001). There was no effect of donor or recipient cobalt/vitamin B12 status on lamb birthweight, neonatal vigour or neonatal rectal temperatures, but lambs derived from +Co v. -Co embryo donors were more active in the first 3 days after birth (P < 0.05). Results show that sub-clinical cobalt/vitamin B12 deficiency reduces ovulatory response in superovulated ewes and that periconception nutrition can affect neonatal lamb behaviour. PMID:17524300

Mitchell, Linda M; Robinson, John J; Watt, Robert G; McEvoy, Thomas G; Ashworth, Cheryl J; Rooke, John A; Dwyer, Cathy M

2007-01-01

193

Ultrafast infrared spectral fingerprints of vitamin B12 and related cobalamins.  

PubMed

Vitamin B(12) (cyanocobalamin, CNCbl) and its derivatives are structurally complex and functionally diverse biomolecules. The excited state and radical pair reaction dynamics that follow their photoexcitation have been previously studied in detail using UV-visible techniques. Similar time-resolved infrared (TRIR) data are limited, however. Herein we present TRIR difference spectra in the 1300-1700 cm(-1) region between 2 ps and 2 ns for adenosylcobalamin (AdoCbl), methylcobalamin (MeCbl), CNCbl, and hydroxocobalamin (OHCbl). The spectral profiles of all four cobalamins are complex, with broad similarities that suggest the vibrational excited states are related, but with a number of identifiable variations. The majority of the signals from AdoCbl and MeCbl decay with kinetics similar to those reported in the literature from UV-visible studies. However, there are regions of rapid (<10 ps) vibrational relaxation (peak shifts to higher frequencies from 1551, 1442, and 1337 cm(-1)) that are more pronounced in AdoCbl than in MeCbl. The AdoCbl data also exhibit more substantial changes in the amide I region and a number of more gradual peak shifts elsewhere (e.g., from 1549 to 1563 cm(-1)), which are not apparent in the MeCbl data. We attribute these differences to interactions between the bulky adenosyl and the corrin ring after photoexcitation and during radical pair recombination, respectively. Although spectrally similar to the initial excited state, the long-lived metal-to-ligand charge transfer state of MeCbl is clearly resolved in the kinetic analysis. The excited states of CNCbl and OHCbl relax to the ground state within 40 ps with few significant peak shifts, suggesting little or no homolysis of the bond between the Co and the upper axial ligand. Difference spectra from density functional theory calculations (where spectra from simplified cobalamins with an upper axial methyl were subtracted from those without) show qualitative agreement with the experimental data. They imply the excited state intermediates in the TRIR difference spectra resemble the dissociated states vibrationally (the cobalamin with the upper axial ligand missing) relative to the ground state with a methyl in this position. They also indicate that most of the TRIR signals arise from vibrations involving some degree of motion in the corrin ring. Such coupling of motions throughout the ring makes specific peak assignments neither trivial nor always meaningful, suggesting our data should be regarded as IR spectral fingerprints. PMID:22612868

Jones, Alex R; Russell, Henry J; Greetham, Gregory M; Towrie, Michael; Hay, Sam; Scrutton, Nigel S

2012-06-14

194

Thermolability of mutant MMACHC protein in the vitamin B12-responsive cblC disorder.  

PubMed

Methylmalonic aciduria and homocystinuria, cblC type, is the most common inborn error of cellular vitamin B12 metabolism. We previously showed that the protein carrying the mutation responsible for late-onset cblC (MMACHC-R161Q), treatable with high dose OHCbl, is able to bind OHCbl with wild-type affinity, leaving undetermined the disease mechanism involved [Froese et al., Mechanism of responsiveness, Mol. Genet. Metab. (2009).]. To assess whether the mutation renders the protein unstable, we investigated the thermostability of the wild-type and mutant MMACHC proteins, either unbound or bound to different cobalamins (Cbl), using differential scanning fluorimetry. We found that MMACHC-wt and MMACHC-R161Q are both very thermolabile proteins in their apo forms, with melting temperatures (T(m)) of 39.3+/-1.0 and 37.1+/-0.7 degrees C, respectively; a difference confirmed by unfolding of MMACHC-R161Q but not MMACHC-wt by isothermal denaturation at 35 degrees C over 120 min. However, with the addition of OHCbl, MMACHC-wt becomes significantly stabilized (Delta T(m max)=8 degrees C, half-maximal effective ligand concentration, AC(50)=3 microM). We surveyed the effect of different cobalamins on the stabilization of the wild-type protein and found that AdoCbl was the most stabilizing, exerting a maximum increase in T(m) of approximately 16 degrees C, followed by MeCbl at approximately 13 degrees C, each evaluated at 50 microM cofactor. The other cobalamins stabilized in the order (CN)(2)Cbi>OHCbl>CNCbl. Interestingly, the AC(50)'s for AdoCbl, MeCbl, (CN)(2)Cbi and OHCbl were similar and ranged from 1-3 microM, which compares well with the K(d) of 6 microM for OHCbl [Froese et al., Mechanism of responsiveness, Mol. Genet. Metab. (2009).]. Unlike MMACHC-wt, the mutant protein MMACHC-R161Q is only moderately stabilized by OHCbl (Delta T(m max)=4 degrees C). The dose-response curve also shows a lower effectivity of OHCbl with respect to stabilization, with an AC(50) of 7 microM. MMACHC-R161Q showed the same order of stabilization as MMACHC-wt, but each cobalamin stabilized this mutant protein less than its wild-type counterpart. Additionally, MMACHC-R161Q had a higher AC(50) for each cobalamin form compared to MMACHC-wt. Finally, we show that MMACHC-R161Q is able to support the base-off transition for AdoCbl and CNCbl, indicating this mutant is not blocked in that respect. Taken together, our results suggest that protein stability, as well as propensity for ligand-induced stabilization, contributes to the disease mechanism in late-onset cblC disorder. Our results underscore the importance of cofactor stabilization of MMACHC and suggest that even small increases in the concentration of cobalamin complexed with MMACHC may have therapeutic benefit in children with the late-onset, vitamin responsive cblC disease. PMID:20219402

Froese, D S; Healy, S; McDonald, M; Kochan, G; Oppermann, U; Niesen, F H; Gravel, R A

2010-05-01

195

A blue corrinoid from partial degradation of vitamin B12 in aqueous bicarbonate: spectra, structure, and interaction with proteins of B12 transport.  

PubMed

Cobalamin (Cbl) is a complex cofactor produced only by bacteria but used by all animals and humans. Cyanocobalamin (vitamin B(12), CNCbl) is one commonly isolated form of cobalamin. B(12) belongs to a large group of corrinoids, which are characterized by a distinct red color conferred by the system of conjugated double bonds of the corrin ring retaining a Co(III) ion. A unique blue Cbl derivative was produced by hydrolysis of CNCbl in a weakly alkaline aqueous solution of bicarbonate. This corrinoid was purified and isolated as dark blue crystals. Its spectroscopic analysis and X-ray crystallography revealed B-ring opening with formation of 7,8-seco-cyanocobalamin (7,8-sCNCbl). The unprecedented structural change was caused by cleavage of the peripheral C-C bond between saturated carbons 7 and 8 of the corrin macrocycle accompanied by formation of a C?C bond at C7 and a carbonyl group at C8. Additionally, the C-amide was hydrolyzed to a carboxylic acid. The extended conjugation of the ?-system caused a considerable red shift of the absorbance spectrum. Formation and degradation of 7,8-sCNCbl were analyzed qualitatively. Its interaction with the proteins of mammalian Cbl transport revealed both a slow binding kinetics and a low overall affinity. The binding data were compared to those of other monocarboxylic derivatives and agreed with the earlier proposed scheme for two-step ligand recognition. The obtained results are consistent with the structural models of 7,8-sCNCbl and the transport proteins intrinsic factor and transcobalamin. Potential applications of the novel derivative for drug conjugation are discussed. PMID:21851077

Fedosov, Sergey N; Ruetz, Markus; Gruber, Karl; Fedosova, Natalya U; Kräutler, Bernhard

2011-09-20

196

Folate, vitamin B12, and vitamin B6 status of a group of high socioeconomic status women in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.  

PubMed

Folic acid supplementation and food fortification policies have improved folate status in North American women of child bearing age. Recent studies have reported the possible inadequacy of vitamin B12 and B6 in the etiology of neural tube defects in folate-fortified populations. The aims of this study were to describe folate status and its relationship to supplementation and to assess vitamin B12 and B6 status in a cohort of pregnant women. Supplement intake data were collected in each trimester from the first cohort (n = 599) of the Alberta Pregnancy Outcomes and Nutrition (APrON) study. Red blood cell folate (RBCF) and plasma folate, holotranscobalamin, and pyridoxal 5-phosphate were measured. Overt folate deficiency was rare (3%) but 24% of women in their first trimester had suboptimal RBCF concentration (<906 nmol·L(-1)). The proportion of the cohort in this category declined substantially in second (9%) and third (7%) trimesters. High RBCF (>1360 nmol·L(-1)) was observed in approximately half of the women during each pregnancy trimester. Vitamin B12 and B6 deficiencies were rare (<1% of the cohort). Women consuming folic acid supplements above the upper level had significantly higher RBCF and plasma folate concentrations. In conclusion, the prevalence of vitamin B12 and B6 deficiency was very low. A quarter of the women had suboptimal folate status in the first trimester of pregnancy and over half the women had abnormally high RBCF, suggesting that supplementation during pregnancy is not appropriate in a cohort of women considered to be healthy and a low risk for nutritional deficiencies. PMID:25386981

Fayyaz, Faiqa; Wang, Flora; Jacobs, René L; O'Connor, Deborah L; Bell, Rhonda C; Field, Catherine J

2014-12-01

197

Enantioselective syntheses of ring-C precursors of vitamin B12. Substrate control. A novel Si-assisted elimination of vinyl bromides.  

PubMed

Homochiral ring-C precursors 34 of Vitamin B(12) have been prepared by Ireland-Claisen rearrangement of allyl esters 32, followed by a novel Si-assisted elimination of HBr. [reaction: see text] PMID:14653697

Jacobi, Peter A; Tassa, Carlos

2003-12-11

198

A preliminary study on the teratogenesis of dexamethasone and the preventive effect of vitamin B 12 on murine embryonic palatal shelf fusion in vitro  

Microsoft Academic Search

Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce\\u000a a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the teratogenic effects of Dex, which, however, remains controversial. In this study, we investigated\\u000a the effects of Dex and vitamin B12 on murine embryonic palatal shelf fusion using

Sheng-jun Lu; Wei He; Bing Shi; Tian Meng; Xiao-yu Li; Yu-rong Liu

2008-01-01

199

Application of the SPE reversed phase HPLC/MS technique to determine vitamin B12 bio-active forms in beef.  

PubMed

Vitamin B12 is an animal origin nutrient of a substantial importance in human diet. Its concentration in foodstuffs is low and its chemical forms are diverse, which significantly hampers its precise determination. The determination method of choice is HPLC (high performance liquid chromatography) coupled with inductively-coupled-plasma mass spectrometry (ICP-MS). The main disadvantage of this method is high instrumentation cost and complexity of handling. The aim of this work was to develop a novel approach for determination of vitamin B12 bio-active forms in beef and beef liver. The proposed method comprises the following steps: (i) vitamin B12 is cleaved off from peptides using thermal denaturation in a weakly acidic environment; (ii) sample is cleaned-up using liquid-liquid extraction and reversed phase solid phase extraction; and finally (iii) vitamin B12 is determined using HPLC and single-quadrupole mass spectrometer with ESI source. Vitamin B12 concentrations in various beef meats were in the 2.84-3.95 ?g 100g(-1) range. Average B12 concentration in beef liver was 153,60 ?g 100g(-1) (n = 15). Major forms of B12 present in beef meat include adenosine cobalamin (AdoCbl) and in smaller quantities hydroxycobalamin (OHCbl). Major forms of vitamin B12 present in beef liver include OHCbl (48.2%), AdoCbl (33.8%), methylocobalamin (MeCbl, 16.3%), and cyanocobalamin (CNCbl, 1.7%). Thermal treatment noticeably decreases B12 the content in meat. Depending on conditions of treatment, B12 concentrations in the 1.04-2.20 ?g 100g(-1) range were found in processed meats. PMID:22429804

Szterk, Arkadiusz; Roszko, Marek; Ma?ek, Krystian; Czerwonka, Ma?gorzata; Waszkiewicz-Robak, Bo?ena

2012-08-01

200

Multiple micronutrient-fortified rice affects physical performance and plasma vitamin B-12 and homocysteine concentrations of Indian school children.  

PubMed

Fortifying rice with multiple micronutrients could be a promising strategy for combat micronutrient deficiencies in developing countries. We determined the efficacy of extruded rice grains fortified with multiple micronutrients on the prevalence of anemia, micronutrient status, and physical and cognitive performance in 6- to 12-y-old, low-income school children in Bangalore, India. In a randomized, double-blind, controlled trial, 258 children were assigned to 1 of 3 intervention groups to receive rice-based lunch meals fortified with multiple micronutrients with either low-iron (6.25 mg) or high-iron (12.5 mg) concentrations or identical meals with unfortified rice. The meals were provided 6 d/wk for 6 mo. Anthropometric, biochemical, physical performance, and cognitive assessments were taken at baseline and endpoint. At baseline, study groups were comparable, with 61% of the children being anemic. However, only <10% were deficient in iron, vitamin A, and zinc. After 6 mo, plasma vitamin B-12 and homocysteine concentrations (both P < 0.001) as well as physical performance (P < 0.05) significantly improved in the intervention arms. No between-group differences were observed in hemoglobin concentration, anemia, and deficiencies of other micronutrients or cognitive function after 6 mo, but paired analyses revealed a small reduction in anemia prevalence in children in the low-iron group. The fortified rice was efficacious in improving vitamin B-12 status and physical performance in Indian school children. PMID:22437556

Thankachan, Prashanth; Rah, Jee Hyun; Thomas, Tinku; Selvam, Sumithra; Amalrajan, Vani; Srinivasan, Krishnamachari; Steiger, Georg; Kurpad, Anura V

2012-05-01

201

Vitamin A and Vitamin B-12 Concentrations in Relation to Mortality and Morbidity among Children Born to HIV-Infected Women  

PubMed Central

Vitamin A supplementation starting at 6 months of age is an important child survival intervention; however, not much is known about the association between vitamin A status before 6 months and mortality among children born to HIV-infected women. Plasma concentrations of vitamins A and B-12 were available at 6 weeks of age (n = 576 and 529, respectively) for children born to HIV-infected women and they were followed up for morbidity and survival status until 24 months after birth. Children in the highest quartile of vitamin A had a 49% lower risk of death by 24 months of age compared to the lowest quartile (HR: 0.51, 95% CI: 0.29–0.90; P-value for trend = 0.01). Higher vitamin A levels were protective in the sub-groups of HIV-infected and un-infected children but this was statistically significant only in the HIV-uninfected subgroup. Higher vitamin A concentrations in plasma are protective against mortality in children born to HIV-infected women. PMID:19502599

Bosch, Ronald J.; Hunter, David J.; Manji, Karim; Msamanga, Gernard I.; Fawzi, Wafaie W.

2010-01-01

202

Human gut microbes use multiple transporters to distinguish vitamin B12 analogs and compete in the gut  

PubMed Central

Summary Genomic and metagenomic sequencing efforts, including human microbiome projects, reveal that microbes often encode multiple systems that appear to accomplish the same task. Whether these predictions reflect actual functional redundancies is unclear. We report that the prominent human gut symbiont Bacteroides thetaiotaomicron employs three functional, homologous vitamin B12 transporters that in at least two cases confer a competitive advantage in the presence of distinct B12 analogs (corrinoids). In the mammalian gut, microbial fitness can be determined by the presence or absence of a single transporter. The total number of distinct corrinoid transporter families in the human gut microbiome likely exceeds those observed in B. thetaiotaomicron by an order of magnitude. These results demonstrate that human gut microbes use elaborate mechanisms to capture and differentiate corrinoids in vivo and that apparent redundancies observed in these genomes can instead reflect hidden specificities that determine whether a microbe will colonize its host. PMID:24439897

Degnan, Patrick H.; Barry, Natasha A.; Mok, Kenny C.; Taga, Michiko E.; Goodman, Andrew L.

2014-01-01

203

A Stability-Indicating HPLC Method for the Determination of Nitrosylcobalamin (NO-Cbl), a Novel Vitamin B12 Analog.  

PubMed

Nitrosylcobalamin (NO-Cbl), a novel vitamin B12 analog and anti-tumor agent, functions as a biologic 'Trojan horse', utilizing the vitamin B12 transcobalamin II transport protein and cell surface receptor to specifically target cancer cells. a stability-indicating HPLC method was developed for the detection of NO-Cbl during forced degradation studies. This method utilized an ascentis(®) RP-amide (150 mm × 4.6 mm, 5 ?m) column at 35 °C with a mobile phase (1.0 mL min(-1)) combining a gradient of methanol and an acetate buffer at pH 6.0. Detection wavelengths of 450 and 254 nm were used to detect corrin and non-corrin-based products, respectively. NO-Cbl, synthesized from hydroxocobalamin and pure nitric oxide gas, was subjected to degradative stress conditions including oxidation, hydrolysis and thermal and radiant energy challenge. The method was validated by assessing linearity, accuracy, precision, detection and quantitation limits and robustness. The method was applied successfully for purity assessment of synthesized NO-Cbl and for the determination of NO-Cbl during kinetic studies in aqueous solution and in solid-state degradation assessments. This HPLC method is suitable for the separation of cobalamins in aqueous and methanolic solutions, for routine detection of NO-Cbl and for purity assessment of synthesized NO-Cbl. additionally, this method has potential application in identification and monitoring of diseases involving altered nitric oxide homeostasis where vitamin B12 therapy is utilized to scavenge excess nitric oxide, subsequently resulting in the in vivo production of NO-Cbl. PMID:24855323

Dunphy, Michael J; Sysel, Annette M; Lupica, Joseph A; Griffith, Kristie; Sherrod, Taylor; Bauer, Joseph A

2014-04-01

204

Effects of differences in serum total homocysteine, folate, and vitamin B 12 on cognitive impairment in stroke patients.  

PubMed

BackgroundVascular cognitive impairment-no dementia (VCIND) refers to the early or mild cognitive impairment induced by cerebral vascular injury. Research shows that serum total homocysteine (tHcy) level is an independent risk factor for cerebral vascular disease and may be closely related to cognitive function.Current studies on the tHcy level in VCIND patients are limited, and the relationship of tHcy with cognitive function remains unclear. This study aims to investigate the tHcy levels in patients with VCIND and to determine their correlation with cognitive function, as well as to provide useful clues for preventing and treating VCIND.MethodsThe tHcy, folate, and vitamin B12 levels in 82 patients with VCIND were reviewed retrospectively and compared with those of 80 stroke patients without cognitive impairment and 69 healthy controls by using the Montreal Cognitive Assessment (MoCA) scale and the event-related potential P300 to evaluate cognitive function.ResultsThe tHcy levels in the VCIND group were higher than those in the other two groups, whereas the folate and Vitamin B12 levels in the VCIND group were lower than those of the other two groups. The tHcy levels in the stroke group were higher than those in the control group, and the folate and vitamin B12 levels in the stroke group were lower than those in the control group. The patients in the VCIND group with high tHcy exhibited lower MoCA scores and prolonged P300 latency than those in with normal tHcy. Correlation analysis showed that tHcy level is positively correlated with P300 latency period and negatively correlated with MoCA score.ConclusionThe tHcy levels were significantly higher and the vitamin B12 and folate levels were significantly lower in the patients with VCIND than those in the other groups. The high tHcy levels in the VCIND patients may be correlated with impaired cognitive function. PMID:25433800

Jiang, Bo; Chen, Yumei; Yao, Guoen; Yao, Cunshan; Zhao, Hongmei; Jia, Xiangdong; Zhang, Yunyan; Ge, Junling; Qiu, Enchao; Ding, Chengyun

2014-11-30

205

Sequential changes in plasma methylmalonic acid and vitamin B12 in sheep eating cobalt-deficient grass.  

PubMed

Methylmalonic acid (MMA) concentrations are elevated in plasma as a result of vitamin B12 deficiency. This study reports the sequential changes in plasma MMA in lambs maintained on a cobalt-deficient pasture compared with supplemented controls. The results indicate that MMA is elevated in the early stages of deficiency, preceding the onset of loss of production and clinical signs of disease. It remains elevated as long as the lambs are unsupplemented with cobalt (Co). The most striking clinical sign was a loss of body condition as opposed to weight. The defect in the methylmalonyl CoA mutase is obviously an early defect in cobalt deficiency. PMID:2484236

Rice, D A; McLoughlin, M; Blanchflower, W J; McMurray, C H; Goodall, E A

1989-11-01

206

ORIGINAL ARTICLE Direct exchange of vitamin B12 is demonstrated by  

E-print Network

, they are unable to grow in its absence. Similarly, 20% require thiamine (vitamin B1) and 5% require biotin genus there are both requirers and nonrequirers: the heterokont Navicula pelliculosa requires thiamine

Cicuta, Pietro

207

Vitamin B12-Impaired Metabolism Produces Apoptosis and Parkinson Phenotype in Rats Expressing the Transcobalamin-Oleosin Chimera in Substantia Nigra  

PubMed Central

Background Vitamin B12 is indispensable for proper brain functioning and cytosolic synthesis of S-adenosylmethionine. Whether its deficiency produces effects on viability and apoptosis of neurons remains unknown. There is a particular interest in investigating these effects in Parkinson disease where Levodopa treatment is known to increase the consumption of S-adenosylmethionine. To cause deprivation of vitamin B12, we have recently developed a cell model that produces decreased synthesis of S-adenosylmethionine by anchoring transcobalamin (TCII) to the reticulum through its fusion with Oleosin (OLEO). Methodology Gene constructs including transcobalamin-oleosin (TCII-OLEO) and control constructs, green fluorescent protein-transcobalamin-oleosin (GFP-TCII-OLEO), oleosin-transcobalamin (OLEO-TCII), TCII and OLEO were used for expression in N1E-115 cells (mouse neuroblastoma) and in substantia nigra of adult rats, using a targeted transfection with a Neurotensin polyplex system. We studied the viability and the apoptosis in the transfected cells and targeted tissue. The turning behavior was evaluated in the rats transfected with the different plasmids. Principal Findings The transfection of N1E-115 cells by the TCII-OLEO-expressing plasmid significantly affected cell viability and increased immunoreactivity of cleaved Caspase-3. No change in propidium iodide uptake (used as a necrosis marker) was observed. The transfected rats lost neurons immunoreactive to tyrosine hydroxylase. The expression of TCII-OLEO was observed in cells immunoreactive to tyrosine hydroxylase of the substantia nigra, with a superimposed expression of cleaved Caspase-3. These cellular and tissular effects were not observed with the control plasmids. Rats transfected with TCII-OLEO expressing plasmid presented with a significantly higher number of turns, compared with those transfected with the other plasmids. Conclusions/Significance In conclusion, the TCII-OLEO transfection was responsible for apoptosis in N1E-115 cells and rat substantia nigra and for Parkinson-like phenotype. This suggests evaluating whether vitamin B12 deficit could aggravate the PD in patients under Levodopa therapy by impairing S-adenosylmethionine synthesis in substantia nigra. PMID:20027219

Orozco-Barrios, Carlos Enrique; Battaglia-Hsu, Shyue-Fang; Arango-Rodriguez, Martha Ligia; Ayala-Davila, Jose; Chery, Celine; Alberto, Jean-Marc; Schroeder, Henry; Daval, Jean-Luc

2009-01-01

208

Associations between Intake of Folate, Methionine, and Vitamins B-12, B-6 and Prostate Cancer Risk in American Veterans  

PubMed Central

Prostate cancer (PC) is the second leading cause of cancer death in men. Recent reports suggest that excess of nutrients involved in the one-carbon metabolism pathway increases PC risk; however, empirical data are lacking. Veteran American men (272 controls and 144 PC cases) who attended the Durham Veteran American Medical Center between 2004–2009 were enrolled into a case-control study. Intake of folate, vitamin B12, B6, and methionine were measured using a food frequency questionnaire. Regression models were used to evaluate the association among one-carbon cycle nutrients, MTHFR genetic variants, and prostate cancer. Higher dietary methionine intake was associated with PC risk (OR = 2.1; 95%CI 1.1–3.9) The risk was most pronounced in men with Gleason sum <7 (OR = 2.75; 95%CI 1.32– 5.73). The association of higher methionine intake and PC risk was only apparent in men who carried at least one MTHFR A1298C allele (OR = 6.7; 95%CI = 1.6–27.8), compared to MTHFR A1298A noncarrier men (OR = 0.9; 95%CI = 0.24–3.92) (p-interaction = 0.045). There was no evidence for associations between B vitamins (folate, B12, and B6) and PC risk. Our results suggest that carrying the MTHFR A1298C variants modifies the association between high methionine intake and PC risk. Larger studies are required to validate these findings. PMID:22927849

Vidal, Adriana C.; Grant, Delores J.; Williams, Christina D.; Masko, Elizabeth; Allott, Emma H.; Shuler, Kathryn; McPhail, Megan; Gaines, Alexis; Calloway, Elizabeth; Gerber, Leah; Chi, Jen-Tsan; Freedland, Stephen J.; Hoyo, Cathrine

2012-01-01

209

Higher prevalence of metformin-induced vitamin B12 deficiency in sulfonylurea combination compared with insulin combination in patients with type 2 diabetes: a cross-sectional study.  

PubMed

Long-term and high-dose treatment with metformin is known to be associated with vitamin B12 deficiency in patients with type 2 diabetes. We investigated whether the prevalence of B12 deficiency was different in patients treated with different combination of hypoglycemic agents with metformin during the same time period. A total of 394 patients with type 2 diabetes treated with metformin and sulfonylurea (S+M group, n?=?299) or metformin and insulin (I+M group, n?=?95) were consecutively recruited. The vitamin B12 and folate levels were quantified using the chemiluminescent enzyme immunoassay. Vitamin B12 deficiency was defined as vitamin B12?300 pg/mL without folate deficiency (folate>4 ng/mL). The mean age of and duration of diabetes in the subjects were 59.4±10.5 years and 12.2±6.7 years, respectively. The mean vitamin B12 level of the total population was 638.0±279.6 pg/mL. The mean serum B12 levels were significantly lower in the S+M group compared with the I+M group (600.0±266.5 vs. 757.7±287.6 pg/mL, P<0.001). The prevalence of vitamin B12 deficiency in the metformin-treated patients was significantly higher in the S+M group compared with the I+M group (17.4% vs. 4.2%, P?=?0.001). After adjustment for various factors, such as age, sex, diabetic duration, duration or daily dose of metformin, diabetic complications, and presence of anemia, sulfonylurea use was a significant independent risk factor for B12 deficiency (OR?=?4.74, 95% CI 1.41-15.99, P?=?0.012). In conclusion, our study demonstrated that patients with type 2 diabetes who were treated with metformin combined with sulfonylurea require clinical attention for vitamin B12 deficiency and regular monitoring of their vitamin B12 levels. PMID:25299054

Kang, Donghoon; Yun, Jae-Seung; Ko, Sun-Hye; Lim, Tae-Seok; Ahn, Yu-Bae; Park, Yong-Moon; Ko, Seung-Hyun

2014-01-01

210

Effects of folate and vitamin B12 on cognitive function in adult and elderly  

Technology Transfer Automated Retrieval System (TEKTRAN)

Age-related neurocognitive disorders, primarily Alzheimer’s disease (AD) and Parkinson’s disease (PD), have a major impact on health and well-being. Separate lines of evidence have suggested that B vitamin status may be associated with risk and progression of AD and PD. This report summarizes the ev...

211

Metabolic interrelationships between folic acid, vitamin B12 and the citrovorum factor  

E-print Network

citrovorum factor (rep rin t )....................................................................... Conversion of folic acid to citrovorum factor by avian liver homogenates. I . Influence of reducing agents and anaerobiosis................................................................... 7 Manometric studies on oxidation of choline by avian liver homogenates (rep rin t )............. Chapter 5* Conversion of folic acid to citrovorum factor by avian liver homogenates, I I . Influence of dietary vitamin B a n d folic a c id...

Doctor, Vasant Manilal

2013-10-04

212

Vitamin B12 diffusion and binding in crosslinked poly(acrylic acid)s and poly(acrylic acid-co-N-vinyl pyrrolidinone)s.  

PubMed

The diffusion mechanism of vitamin B12 in two types of crosslinked hydrogels, poly(acrylic acid) (cPAA) and copolymers of acrylic acid and N-vinyl pyrrolidinone (cP(AA-NVP)) was studied. The PAA and P(AA-NVP) synthesized by three different degrees of crosslinking have limited water absorption capabilities ranging from 3% to 18%. In the copolymers permeability of B12 is controlled by both intramolecular and intermolecular hydrogen-bonding between the pyrrolidinone and carboxylic acid side chains. The diffusion kinetic data in two types of polymers were best described by Peppas models instead of Higuchi models. Permeation from both crosslinked PAA and P(AA-co-NVP) copolymers followed a Super Case II transport mechanism, most likely driven by macromolecular chain relaxation and swelling of hydrophilic polymers. A special FTIR spectroscopic method for drug binding study, FTIR difference spectroscopy, is used to probe the strong interactions between vitamin B12 and the side chains of the hydrogels. The FTIR differential spectra of B12 in PAA hydrogels revealed dramatic changes of the spectral marker bands of B12 after binding in the crosslinked gels, indicating significant interactions occurring in the amide and phosphate moieties of B12. Such interactions retard the diffusion of vitamin B12. PMID:19138732

Jin, Lei; Lu, Ping; You, Huanhuan; Chen, Qiang; Dong, Jian

2009-04-17

213

Some histological manifestations in the vitamin B b12 sdeficient newborn rat  

E-print Network

&dna;, . and spieen 1n duced by a materw?l v1tamin Rl? deficiency 1? the ?suborn albino rat, 4 secondary porno a Ips to co"lpga e the '?Jot'. , +t dif faro loca bot'i&en the hearts, livorn and '. . Tdnevs of novborn offspring oi' v'to oin Q 2 deficient mothers... newborn albino rats of a strain Inintained 25 years at the college, Females which had been reared on a soybean oQ. cnai diet (PQ44) . M+t was very low in vitamin SI2 were used as the matavnal pueuts. The coapositf?n of this diet is given belowi Xahim...

Jones, Carroll Christian

2012-06-07

214

Conformational cycle of the vitamin B12 ABC importer in liposomes detected by double electron-electron resonance (DEER).  

PubMed

Double electron-electron resonance is used here to investigate intermediates of the transport cycle of the Escherichia coli vitamin B12 ATP-binding cassette importer BtuCD-F. Previously, we showed the ATP-induced opening of the cytoplasmic gate I in TM5 helices, later confirmed by the AMP-PNP-bound BtuCD-F crystal structure. Here, other key residues are analyzed in TM10 helices (positions 307 and 322) and in the cytoplasmic gate II, i.e. the loop between TM2 and TM3 (positions 82 and 85). Without BtuF, binding of ATP induces detectable changes at positions 307 and 85 in BtuCD in liposomes. Together with BtuF, ATP triggers the closure of the cytoplasmic gate II in liposomes (reported by both positions 82 and 85). This forms a sealed cavity in the translocation channel in agreement with the AMP-PNP·BtuCD-F x-ray structure. When vitamin B12 and AMP-PNP are simultaneously present, the extent of complex formation is reduced, but the short 82-82 interspin distance detected indicates that the substrate does not affect the closed conformation of this gate. The existence of the BtuCD-F complex under these conditions is verified with spectroscopically orthogonal nitroxide and Gd(III)-based labels. The cytoplasmic gate II remains closed also in the vanadate-trapped state, but it reopens in the ADP-bound state of the complex. Therefore, we suggest that the substrate likely trapped in ATP·BtuCD-F can be released after ATP hydrolysis but before the occluded ADP-bound conformation is reached. PMID:24362024

Joseph, Benesh; Korkhov, Vladimir M; Yulikov, Maxim; Jeschke, Gunnar; Bordignon, Enrica

2014-02-01

215

Vision changes after spaceflight are related to alterations in folate- and vitamin B-12-dependent one-carbon metabolism.  

PubMed

Approximately 20% (7 of 38) of astronauts on International Space Station (ISS) missions have developed measurable ophthalmic changes after flight. This study was conducted to determine if the folate- and vitamin B-12-dependent 1-carbon metabolic pathway is altered in these individuals. Since 2006, we have conducted experiments on the ISS to evaluate nutritional status and related biochemical indices of astronauts before, during, and after flight. Data were modeled to evaluate differences between individuals with ophthalmic changes (n = 5) and those without them (n = 15), all of whom were on ISS missions of 48-215 d. We also determined whether mean preflight serum concentrations of the 1-carbon metabolites and changes in measured cycloplegic refraction after flight were associated. Serum homocysteine (Hcy), cystathionine, 2-methylcitric acid (2MCA), and methylmalonic acid concentrations were 25-45% higher (P < 0.001) in astronauts with ophthalmic changes than in those without them. These differences existed before, during, and after flight. Preflight serum concentrations of Hcy and cystathionine, and mean in-flight serum folate, were correlated with change (postflight relative to preflight) values in refraction (P < 0.05), and preflight serum concentrations of 2MCA tended to be associated (P = 0.06) with ophthalmic changes. The biochemical differences observed in crewmembers with vision issues strongly suggest that their folate- and vitamin B-12-dependent 1-carbon transfer metabolism was affected before and during flight. The consistent differences in markers of 1-carbon metabolism between those who did and those who did not develop changes in vision suggest that polymorphisms in enzymes of this pathway may interact with microgravity to cause these pathophysiologic changes. PMID:22298570

Zwart, Sara R; Gibson, C Robert; Mader, Thomas H; Ericson, Karen; Ploutz-Snyder, Robert; Heer, Martina; Smith, Scott M

2012-03-01

216

Direct exchange of vitamin B12 is demonstrated by modelling the growth dynamics of algal-bacterial cocultures.  

PubMed

The growth dynamics of populations of interacting species in the aquatic environment is of great importance, both for understanding natural ecosystems and in efforts to cultivate these organisms for industrial purposes. Here we consider a simple two-species system wherein the bacterium Mesorhizobium loti supplies vitamin B12 (cobalamin) to the freshwater green alga Lobomonas rostrata, which requires this organic micronutrient for growth. In return, the bacterium receives photosynthate from the alga. Mathematical models are developed that describe minimally the interdependence between the two organisms, and that fit the experimental observations of the consortium. These models enable us to distinguish between different mechanisms of nutrient exchange between the organisms, and provide strong evidence that, rather than undergoing simple lysis and release of nutrients into the medium, M. loti regulates the levels of cobalamin it produces, resulting in a true mutualism with L. rostrata. Over half of all microalgae are dependent on an exogenous source of cobalamin for growth, and this vitamin is synthesised only by bacteria; it is very likely that similar symbiotic interactions underpin algal productivity more generally. PMID:24522262

Grant, Matthew A A; Kazamia, Elena; Cicuta, Pietro; Smith, Alison G

2014-07-01

217

Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification  

Technology Transfer Automated Retrieval System (TEKTRAN)

Historic data on folic acid treatment of pernicious anemia suggested that high-level fortification would delay diagnosis or exacerbate effects of vitamin B12 deficiency, which affects many seniors. This idea is controversial, however, because observational data are few and inconclusive and experime...

218

Metabolic evidence of vitamin B-12 deficiency, including high homocysteine and methylmalonic acid and low holotranscobalamin, is more pronounced in older adults with elevated plasma folate  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: An analysis of data from the National Health and Nutrition Examination Survey indicated that in older adults exposed to folic acid fortification, the combination of low serum vitamin B-12 and elevated folate is associated with higher concentrations of homocysteine and methylmalonic acid ...

219

In vitamin B12 deficiency, higher serum folate is assoicated with increased total homocysteine (tHcy) and methlmalonic acid (MMA) concentrations  

Technology Transfer Automated Retrieval System (TEKTRAN)

In a recent study of older participants (age >/= 60 y) in the 1999-2002 National Health and Nutrition Examination Survey (NHANES), we showed that a combination of high serum folate and low vitamin B-12 status was associated with higher prevalence of cognitive impairment and anemia than other combina...

220

The Chilean Flour Folic Acid Fortification Program Reduces Serum Homocysteine Levels and Masks Vitamin B12 Deficiency in Elderly People1  

Microsoft Academic Search

Hyperhomocysteinemia is considered a risk factor for cardiovascular disease and is prevalent in the elderly. Supplementation with folic acid, vitamin B-6 and B-12 lowers homocysteine levels. In January 2000, the Chil- ean government initiated a flour folic acid fortification pro- gram to decrease the occurrence of neural tube defects. The aim of this study was to evaluate the effect of

Sandra Hirsch; Pia de la Maza; Gladys Barrera; Vivian Gattas; Margarita Petermann; Daniel Bunout

221

Basic haematological parameters, serum gamma-glutamyl-transferase activity, and erythrocyte folate and serum vitamin B12 levels during carbamazepine and oxcarbazepine therapy.  

PubMed

Basic haematologic parameters and serum gamma-glutamyl-transferase (GGT) activity were evaluated in a five-year prospective follow-up study of 25 patients with newly diagnosed epilepsy starting treatment with carbamazepine. In addition, we evaluated the effects of replacing carbamazepine by oxcarbazepine on these parameters, erythrocyte folate concentrations and serum vitamin B12 levels in 12 male patients with epilepsy. The mean white blood cell count (WBC) and red blood cell count decreased after 2 months carbamazepine therapy, and remained at this lower level during the first 5 years of medication. The mean erythrocyte volume (MCV) and the serum GGT activity increased progressively during carbamazepine treatment. The serum GGT activity decreased after replacing carbamazepine by oxcarbazepine indicating a normalization of the liver P450 enzyme system induction. Concomitantly, the erythrocyte folate concentrations and serum levels of vitamin B12 increased, and the WBC increased and MCV decreased. It is probable that the changes in folate metabolism and serum vitamin B12 concentrations are due to normalization of the liver P450 enzyme system induction after the change of medication. The haematologic changes during carbamazepine medication, and their normalization after replacing carbamazepine by oxcarbazepine are possibly related to changes in folate and vitamin B12 metabolism. PMID:9203249

Isojärvi, J I; Pakarinen, A J; Myllylä, V V

1997-06-01

222

Metabolic Vitamin B12 Status on a Mostly Raw Vegan Diet with Follow-Up Using Tablets, Nutritional Yeast, or Probiotic Supplements  

Microsoft Academic Search

Background: Pure vegetarian diets might cause cobalamin deficiency due to lack of dietary intake. It was hypothesized that a population following a vegan diet consuming mostly raw fruits and vegetables, carrot juice, and dehydrated barley grass juice would be able to avoid vitamin B12 deficiency naturally. Methods: Subjects were recruited at a health ministers’ reunion based on adherence to the

Michael S. Donaldson

2000-01-01

223

Preliminary Evidence for Cell Membrane Amelioration in Children with Cystic Fibrosis by 5-MTHF and Vitamin B12 Supplementation: A Single Arm Trial  

PubMed Central

Background Cystic fibrosis (CF) is one of the most common fatal autosomal recessive disorders in the Caucasian population caused by mutations of gene for the cystic fibrosis transmembrane conductance regulator (CFTR). New experimental therapeutic strategies for CF propose a diet supplementation to affect the plasma membrane fluidity and to modulate amplified inflammatory response. The objective of this study was to evaluate the efficacy of 5-methyltetrahydrofolate (5-MTHF) and vitamin B12 supplementation for ameliorating cell plasma membrane features in pediatric patients with cystic fibrosis. Methodology and Principal Findings A single arm trial was conducted from April 2004 to March 2006 in an Italian CF care centre. 31 children with CF aged from 3 to 8 years old were enrolled. Exclusion criteria were diabetes, chronic infections of the airways and regular antibiotics intake. Children with CF were supplemented for 24 weeks with 5-methyltetrahydrofolate (5-MTHF, 7.5 mg /day) and vitamin B12 (0.5 mg/day). Red blood cells (RBCs) were used to investigate plasma membrane, since RBCs share lipid, protein composition and organization with other cell types. We evaluated RBCs membrane lipid composition, membrane protein oxidative damage, cation content, cation transport pathways, plasma and RBCs folate levels and plasma homocysteine levels at baseline and after 24 weeks of 5-MTHF and vitamin B12 supplementation. In CF children, 5-MTHF and vitamin B12 supplementation (i) increased plasma and RBC folate levels; (ii) decreased plasma homocysteine levels; (iii) modified RBC membrane phospholipid fatty acid composition; (iv) increased RBC K+ content; (v) reduced RBC membrane oxidative damage and HSP70 membrane association. Conclusion and Significance 5-MTHF and vitamin B12 supplementation might ameliorate RBC membrane features of children with CF. Trial Registration ClinicalTrials.gov NCT00730509 PMID:19277125

Scambi, Cinzia; De Franceschi, Lucia; Guarini, Patrizia; Poli, Fabio; Siciliano, Angela; Pattini, Patrizia; Biondani, Andrea; La Verde, Valentina; Bortolami, Oscar; Turrini, Francesco; Carta, Franco; D'Orazio, Ciro; Assael, Baroukh M.; Faccini, Giovanni; Bambara, Lisa M.

2009-01-01

224

Crystal structure of putative CbiT from Methanocaldococcus jannaschii: an intermediate enzyme activity in cobalamin (vitamin B12) biosynthesis  

PubMed Central

Background In the anaerobic pathway of cobalamin (vitamin B12) synthesis, the CbiT enzyme plays two roles, as a cobalt-precorrin-7 C15-methyltransferase and a C12-decarboxylase, to produce the intermediate, cobalt-precorrin 8. Results The primary structure of the hypothetical protein MJ0391, from Methanocaldococcus jannaschii, suggested that MJ0391 is a putative CbiT. Here, we report the crystal structure of MJ0391, solved by the MAD procedure and refined to final R-factor and R-free values of 19.8 & 27.3%, respectively, at 2.3 Å resolution. The asymmetric unit contains two NCS molecules, and the intact tetramer generated by crystallographic symmetry may be functionally important. The overall tertiary structure and the tetrameric arrangements are highly homologous to those found in MT0146/CbiT from Methanobacterium thermoautotrophicum. Conclusions The conservation of functional residues in the binding site for the co-factor, AdoMet, and in the putative precorrin-7 binding pocket suggested that MJ0391 may also possess CbiT activity. The putative function of MJ0391 is discussed, based on structural homology. PMID:23688113

2013-01-01

225

Comparison of directly compressed vitamin B12 tablets prepared from micronized rotary-spun microfibers and cast films.  

PubMed

Abstract Fiber-based dosage forms are potential alternatives of conventional dosage forms from the point of the improved extent and rate of drug dissolution. Rotary-spun polymer fibers and cast films were prepared and micronized in order to direct compress after homogenization with tabletting excipients. Particle size distribution of powder mixtures of micronized fibers and films homogenized with tabletting excipients were determined by laser scattering particle size distribution analyzer. Powder rheological behavior of the mixtures containing micronized fibers and cast films was also compared. Positron annihilation lifetime spectroscopy was applied for the microstructural characterization of micronized fibers and films. The water-soluble vitamin B12 release from the compressed tablets was determined. It was confirmed that the rotary spinning method resulted in homogeneous supramolecularly ordered powder mixture, which was successfully compressed after homogenization with conventional tabletting excipients. The obtained directly compressed tablets showed uniform drug release of low variations. The results highlight the novel application of micronized rotary-spun fibers as intermediate for further processing reserving the original favorable powder characteristics of fibrous systems. PMID:25190153

Sebe, István; Bodai, Zsolt; Eke, Zsuzsanna; Kállai-Szabó, Barnabás; Szabó, Péter; Zelkó, Romána

2014-09-01

226

Effect of folic acid and vitamin B12 on pemetrexed antifolate chemotherapy in nutrient lung cancer cells.  

PubMed

Pemetrexed (MTA) is a multitargeted antifolate drug approved for lung cancer therapy. Clinically, supplementation with high doses of folic acid (FA) and vitamin B12 (VB12) lowers MTA cytotoxicities. An antagonistic effect of FA/VB12 on MTA efficacy has been proposed. However, patients who receive FA/VB12 show better tolerance to MTA with improved survival. The aims of this study are to investigate the modulation of FA and VB12 on MTA drug efficacy in human nonsmall cell lung cancer (NSCLC) cell lines. The sensitivities of cells, apoptosis, and MTA-regulated proteins were characterized to determine the possible effects of high doses of FA and VB12 on MTA efficacy. MTA has the lowest efficacy under 10% serum conditions. However, supplementation with FA and VB12 individually and additively reversed the insensitivity of NSCLC cells to MTA treatment with 10% serum. The enhanced sensitivities of cells following FA/VB12 treatment were correlated with increasing apoptosis and were specific to MTA but not to 5-fluorouracil (5-FU). Enhanced sensitivity was also associated with p21(WAF1/Cip1) expression level. Our results revealed no antagonistic effect of high doses of FA/VB12 on MTA efficacy in cancer cells grown in nutrient medium. Furthermore, these data may partially explain why supplementation of FA and VB12 resulted in better survival in MTA-treated patients. PMID:23984356

Yang, Tsung-Ying; Chang, Gee-Chen; Hsu, Shih-Lan; Huang, Yi-Rou; Chiu, Ling-Yen; Sheu, Gwo-Tarng

2013-01-01

227

Selective intestinal malabsorption of vitamin B12 displays recessive Mendelian inheritance: Assignment of a locus to chromosome 10 by linkage  

SciTech Connect

Juvenile megaloblastic anemia caused by selective intestinal malabsorption of vitamin B12 has been considered a distinct condition displaying autosomal recessive inheritance. It appears to have a worldwide distribution, and comparatively high incidences were reported 30 years ago in Finland and Norway. More recently, the Mendelian inheritance of the condition has been questioned because almost no new cases have occurred in these populations. Here we report linkage studies assigning a recessive-gene locus for the disease to chromosome 10 in previously diagnosed multiplex families from Finland and Norway, proving the Mendelian mode of inheritance. The locus is tentatively assigned to the 6-cM interval between markers D10S548 and D10S466, with a multipoint maximum lod score (Z{sub max}) of 5.36 near marker D10S1477. By haplotype analysis, the healthy sibs in these families did not appear to constitute any examples of nonpenetrance. We hypothesize that the paucity of new cases in these populations is due either to a dietary effect on the gene penetrance that has changed with time, or to a drop in the birth rate in subpopulations showing enrichment of the mutation, or to both of these causes. 38 refs., 4 figs., 2 tabs.

Aminoff, M.; Tahvanainen, E.; Chapelle, A. de la [Univ. of Helsinki (Finland)] [and others

1995-10-01

228

Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older hispanics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: A common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues. Methods: TC genotype and its associations with i...

229

Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older Hispanics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: A common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues. Methods: TC genotype and its associations with i...

230

Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin  

SciTech Connect

There is need for an improved test of human ability to assimilate dietary vitamin B{sub 12}. Assaying and understanding absorption and uptake of B{sub 12} is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of {sup 14}C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ({sup 14}C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B{sub 12} in the range of normal dietary intake. The B{sub 12} used was quantitatively labeled with {sup 14}C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B{sub 12} or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with {sup 14}C-DMB specifically labeled in the C2 position, cells produced {sup 14}C-B{sub 12} of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified {sup 14}C-B{sub 12} was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B{sub 12} assimilation.

Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

2006-01-26

231

Measured Electron Spin Relaxation Rates in Frozen Solutions of Azurin, VITAMIN-B12R, and Nitrosyl Ferrous Myoglobin.  

NASA Astrophysics Data System (ADS)

Rates in frozen glycerin/water solutions at temperatures between 1.4 K and 20 K are reported for a copper-containing protein, azurin, and a cobalt-containing biomolecular complex, vitamin B_{rm 12r}, the paramagnetic product of the photolysis of coenzyme B_{12}. Results are interpreted in terms of a spectral dimensionality. Rates are also reported for nitrosyl ferrous myoglobin in frozen water solution, which exhibits a dominant one-phonon relaxation process up to 20 K and thus does not reveal spectral dimensionality. The anomalous variation of rate with temperature observed in several iron-containing proteins is not conspicuous here. In a model two-phonon mechanism of relaxation, temperature dependence is fixed by a spectral dimensionality, m, which specifies the variation of vibrational density of states with frequency rho(nu ) ~ nu ^{rm m-1} and is named in analogy with the Debye density of states in 1-, 2-, and 3-dimensional crystals. At sufficiently high temperatures, a non-resonant two-phonon process (Raman) should dominate the relaxation of a paramagnetic ion unless low-lying (under ^{~}70 cm^ {-1}) electronic states are present, as in many rare earths and in high spin ferric complexes, including many ferric proteins. The temperature dependence of the Raman rate for a Kramers ion (odd number of electrons) is T^{rm 3+2m} if temperature is sufficiently lower than Theta = hnu_{rm max} /k, the Debye temperature. The values of m from relaxation data on frozen solutions of a protein have sometimes been dependent upon solvent conditions. The maximum values of m for heme proteins, iron-sulfur proteins, and one copper -and-iron-containing protein, have ranged from about 1.3 to 1.8. Pulse saturation/recovery was used. The recoveries were not exponential, but rates were estimated from semilogarithmic displays of signals or from numerical fitting. The temperature dependence of the rates for azurin between 1.5 K and 22 K can be fit with a spectral dimensionality of 3 and a rather low Debye temperature near 69 K, in contrast to iron proteins. Relaxation of vitamin B_{ rm 12r} differed between samples, indicating varied photolysis or freezing. The Raman relaxation was well fit by a simple power law in temperature, but the values of m varied from 1.14 to 1.48 between samples.

Muench, Philip James

232

The vitamin B12 analog cobinamide is an effective hydrogen sulfide antidote in a lethal rabbit model  

PubMed Central

Background and purpose Hydrogen sulfide (H2S) is a highly toxic gas for which no effective antidotes exist. It acts, at least in part, by binding to cytochrome c oxidase, causing cellular asphyxiation and anoxia. We investigated the effects of three different ligand forms of cobinamide, a vitamin B12 analog, to reverse sulfide (NaHS) toxicity. Methods New Zealand white rabbits received a continuous intravenous (IV) infusion of NaHS (3 mg/min) until expiration or a maximum 270 mg dose. Animals received six different treatments, administered at the time when they developed signs of severe toxicity: Group 1—saline (placebo group, N = 9); Group 2—IV hydroxocobalamin (N = 7); Group 3—IV aquohydroxocobinamide (N = 6); Group 4—IV sulfitocobinamide (N = 6); Group 5—intramuscular (IM) sulfitocobinamide (N = 6); and Group 6—IM dinitrocobinamide (N = 8). Blood was sampled intermittently, and systemic blood pressure and deoxygenated and oxygenated hemoglobin were measured continuously in peripheral muscle and over the brain region; the latter were measured by diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS). Results Compared with the saline controls, all cobinamide derivatives significantly increased survival time and the amount of NaHS that was tolerated. Aquohydroxocobinamide was most effective (261.5 ± 2.4 mg NaHS tolerated vs. 93.8 ± 6.2 mg in controls, p < 0.0001). Dinitrocobinamide was more effective than sulfitocobinamide. Hydroxocobalamin was not significantly more effective than the saline control. Conclusions Cobinamide is an effective agent for inhibiting lethal sulfide exposure in this rabbit model. Further studies are needed to determine the optimal dose and form of cobinamide and route of administration. PMID:24716792

BRENNER, M.; BENAVIDES, S.; MAHON, S. B.; LEE, J.; YOON, D.; MUKAI, D.; VISEROI, M.; CHAN, A.; JIANG, J.; NARULA, N.; AZER, S. M.; ALEXANDER, C.; BOSS, G. R.

2014-01-01

233

Effects of low concentrations of dietary cobalt on liveweight gains, haematology, serum vitamin B(12) and biochemistry of Omani goats.  

PubMed

Seventy-three, 10-week-old, newly weaned Omani goats of three different breeds, namely Dhofari (D), Batinah (B) and Jebel Akhdar (JA) were randomly divided into a control (n=38) and a treated group (n=35) for an experimental period of 10 months. Goats in both groups were fed 150 g/day per head of a pelleted concentrate, based on body weight and their requirements and Rhodes grass hay ad libitum, containing 0.12 and 0.10 mg/kg DM cobalt, respectively. Goats in the treated group also received bi-monthly subcutaneous injections of 2000 microg hydroxycobalamin. In contrast to the treated goats, the control animals of all breeds experienced a severe decrease in their serum vitamin B(12) levels, developed pale mucous membranes, appeared scruffy and two breeds (D and B) had significantly lower weight gains from month 5. Untreated kids of all breeds had significant decreases in their red blood cell counts and erythrocyte indices after approximately four months. Controls developed low total serum protein levels whilst activities of alkaline phosphatase and aspartate aminotransferase significantly increased. Although it is widely assumed that goats are more resistant to cobalt deficiency than sheep this is apparently not true for Omani goats. Based on experimental data from previously reported studies and those from the present study it can be concluded that the reduction in weight gains in D and B goats is related to their lower digestibility coefficients for dry matter, crude protein and energy while the increase in alkaline phosphatase and aspartate aminotransferase are associated with developing hepatic lipidosis. PMID:16324857

Al-Habsi, Khalid; Johnson, Eugene H; Kadim, Isam T; Srikandakumar, Anandarajah; Annamalai, Kanthi; Al-Busaidy, Rashid; Mahgoub, Osman

2007-01-01

234

One-step induction of neurons from mouse embryonic stem cells in serum-free media containing vitamin B12 and heparin.  

PubMed

We present a simple method for neural cell fate specification directly from mouse embryonic stem cells (ES cells) in serum-free conditions in the absence of embryoid body formation. Dissociated ES cells were cultured in serum-free media supplemented with vitamin B12 and heparin, but without any expensive cytokines. After 14 days in culture, beta-tubulin type III (TuJ1) and tyrosine hydroxylase (TH)-positive colonies were detected by immunocytochemical examinations. In addition, specific gene analyses by RT-PCR demonstrated expression of an early central nerve system, mature neuron, and midbrain dopaminergic neuron-specific molecules (i.e., nestin, middle molecular mass neurofilament protein, Nurr1, and TH, respectively). Dopamine was also detected in the culture media by reverse-phase HPLC analysis. These facts indicate that addition of vitamin B12/heparin to serum-free culture media induced neurons from ES cells, which included cells that released dopamine. Other supplements, such as putrescine, biotin, and Fe2+, could not induce neurons from ES cells by themselves, but produced synergistic effects with vitamin B12/heparin. The rate of TuJ1+/TH+ colony formation was increased threefold and the amounts of dopamine released increased 1.5-fold by the addition of a mixture of putrescine, biotin, and Fe2+ to vitamin B12/heparin culture media. Our method is a simple tool to differentiate ES cells to dopaminergic neurons for the preparation of dopamine-releasing cells for the cell transplantation therapy of Parkinson's disease. In addition, this method can facilitate the discovery of soluble factors and genes that can aid in the induction of the ES cell to its neural fate. PMID:16719047

Yamazoe, Hironori; Kobori, Masato; Murakami, Yoshinobu; Yano, Keiichi; Satoh, Mitsuo; Mizuseki, Kenji; Sasai, Yoshiki; Iwata, Hiroo

2006-01-01

235

Influence of dietary cobalt source and concentration on performance, vitamin B12 status, and ruminal and plasma metabolites in growing and finishing steers1,2  

Microsoft Academic Search

Sixty Angus steers, averaging 274 kg, were used to evaluate the effects of Co source and con- centration on performance, vitamin B12 status, and metabolic characteristics of steers. Treatments con- sisted of 0 (control, analyzed 0.04 mg Co\\/kg), 0.05, 0.10, and 1.0 mg of supplemental Co\\/kg of DM from CoCO3 or 0.05 and 0.10 mg of supplemental Co\\/kg of DM

M. E. Tiffany; J. W. Spears; L. Xi; J. Horton; Kemin Americas

2010-01-01

236

Changes in serum concentrations of methylmalonic acid and vitamin B12 in cobalt-supplemented ewes and their lambs on two cobalt-deficient properties  

Microsoft Academic Search

AIM: To determine concurrent changes in serum methylmalonic acid (MMA) and vitamin B12 concentrations of ewes and their lambs on cobalt-deficient properties, subsequent to cobalt supplementation.METHODS: Three experiments were carried out on two farms. Groups of ewes (n=25?50) were either supplemented with cobalt bullets during late pregnancy, 23–47 days before the mean lambing date, or left unsupplemented. In two experiments,

TM Gruner; JR Sedcole; JM Furlong; ND Grace; SD Williams; G Sinclair; AR Sykes

2004-01-01

237

Comparative effects of low levels of dietary cobalt and parenteral injections of Vitamin B 12 on body dimensions in different breeds of Omani goats  

Microsoft Academic Search

The effect of low levels of dietary cobalt and parenteral Vitamin B12 supplementation on live body weight and the body dimensions of three breeds of Omani intact male goats, namely Batina (14 goats), Dhofari (14 goats) and Jabal Al-Akdhar (14 goats). The animals were fed Rhodes grass hay and a commercial diet containing 0.10 and 0.12mg\\/kgDM of cobalt, respectively, from

I. T. Kadim; O. Mahgoub; D. Al-Ajmi; K. R. Al-Habsi; E. H. Johnson

2006-01-01

238

The vitamin B 1 , B 2 , B 6 , B 12 , and E contents of hard red spring wheat as influenced by fertilization and cultivar  

Microsoft Academic Search

To evaluate the effects of fertilization and cultivar on the content of vitamins B1, B2, B6, B12, and E in wheat, seven fertility treatments with three levels of N (0, 56, and 280 kg\\/ha), two levels of P (0 and 122 kg\\/ha), and two levels of K (0 and 465 kg\\/ha) were applied on split plots to two relatively unrelated

Paul W. Syltie; William C. Dahnke

1983-01-01

239

Development and validation of PCR, PLS, and TLC densitometric methods for the simultaneous determination of vitamins B(1), B(6) AND B(12) in pharmaceutical formulations.  

PubMed

This work represents the simultaneous determination of thiamine hydrochloride (B(1)), pyridoxine hydrochloride (B(6)) and cyanocobalamine (B(12)) by two different methods namely spectrophotometry multivariate calibration and densitometry. The spectrophotometric numerical method depends on the use of spectrophotometric data coupled to PLS and PCR multivariate calibration methods for the simultaneous determination of (B(1)) and (B(6)) in the presence of (B(12)) in laboratory prepared mixtures and commercial tablets. A calibration set was prepared, where the three vitamins were modeled using a full factorial 23 with three center points experimental design. This calibration set was used to build the PLS and PCR models. The models were validated by testing their predictive ability on a validation set where low RMSEP, RSEP % were obtained for both models. Figures of merit were determined using the net analyte signal concept. The proposed models were applied successfully to simultaneous determination of B1 and B6 in presence of a low concentration of B12 in pharmaceutical dosage forms that contain simple excipients. The TLC densitometric method was based on the use of a developing system of chloroform: ethanol: water: acetic acid solution (2: 8: 2: 0.5 v/v) to separate the three vitamins. The separated spots were scanned at 242nm, 291nm and 360nm for B(1), B(6) and B(12) respectively. The proposed method was applied successfully to simultaneous determination of the three vitamins in their pure powder form in the range 0.1-1.5 (µg/spot), 0.5-3.5 (µg/spot), 0.1-1.5 (µg/spot) for B(1), B(6), and B(12) respectively and in their pharmaceutical formulations. PMID:20884455

Elzanfaly, Eman S; Nebsen, Marianne; Ramadan, Nesreen K

2010-10-01

240

Novel in situ product removal technique for simultaneous production of propionic acid and vitamin B12 by expanded bed adsorption bioreactor.  

PubMed

A new type of in situ product removal (ISPR) technique of expanded bed adsorption (EBA) bioreactor was studied to simultaneously produce extracellular propionic acid and intracellular vitamin B12 by Propionibacterium freudenreichii CICC 10019. Resin screening experiments showed that the ZGA330 resin have the best biocompatibility and highest adsorption for propionic acid. Through the EBA bioreactor, propionic acid could be recovered efficiently by semi-continuous recirculation of the unfiltered broth, which eliminated the feedback inhibition of propionic acid. Fed-batch fermentation was carried out using the EBA system, resulting in a propionic acid concentration of 52.5 g L(-1) and vitamin B12 concentration of 43.04 mg L(-1) at 160 h, which correspond to product yields of 0.66 g g(-1) and 0.54 mg g(-1), respectively. The present study suggests that the EBA bioreactor can be utilized for the simple and economical production of propionic acid and vitamin B12 in a single fermentation process. PMID:22082511

Wang, Peng; Wang, Yunshan; Liu, Yongdong; Shi, Hong; Su, Zhiguo

2012-01-01

241

Determining the Effect of Gutkha on Serum Levels of Vitamin B12 and Folic Acid as Compared to Smoking among Chronic Periodontitis Subjects : A Cross-Sectional Study  

PubMed Central

Background: Periodontitis, being a common inflammatory disease has a multifactorial origin , with smoking and gutkha as few of the causative entities. The role of smoking as a risk factor for periodontitis is been well documented in literature. Cigarette smoke also affects vitamin B12 and folic acid mechanisms. Nutritionally derived vitamin B12 occurs mainly as either hydroxycobalamin or deoxyadenosycobalmin. Folic acid is also heat sensitive and water soluble, closely linked to vitamin B12 in its metabolism. However, effect of smokeless tobacco in form of gutkha on serum levels of vitamin B12 and folic acid is yet to be explored. Aims and Objectives: To estimate and correlate serum vitamin B12 (VB12) and folic acid (FA) levels among periodontally healthy subjects and Chronic Periodontitis (CP) subjects with habit of smoking and gutkha chewing. Materials and Methods: The study included 111 subjects ranging in age from 18 to 60 y. Participants were divided into four groups: 30 healthy subjects (Group I), 29 subjects with CP (Group II), 25 smokers with CP (Group III) and 27 gutkha chewers with CP (Group IV). Clinical parameters included pocket probing depth (PPD), clinical attachment level (CAL) & gingival index (GI) following which VB12 and FA levels were estimated through UV-spectrophotometry method and data was analysed using Statistical Package for Social Scientists software, Mann-Whitney U-test and Pearson correlation coefficient. p-values less than 0.05 were considered as significant. Results : Pairwise comparison by Mann-Whitney U-test showed an increase in the serum VB12 in Group IV when compared to Group I (p=0.01) and Group II (p=0.01). Although serum FA levels were found to be low in Group III (7.61 ug/ml) & Group IV (8.64 ug/ml), Group III was found to be statistically significant (P=0.046). The clinical parameters GI, PPD and CAL among the four groups of patients were also statistically significant (p < 0.05). Conclusion: The study results suggested that among the patients with periodontal disease, serum VB12 levels are directly related while serum FA levels are inversely related to inflammation and tissue destruction in periodontium as occurred in Group IV. PMID:25654040

Warad, Shivaraj; Kalburgi, Nagaraj B; Kalburgi, Veena C; Koregol, Arati C; Patanashetti, Jyoti; Rao, Subramaniam; Kokatnur, M. Vijayalaxmi

2014-01-01

242

Methylmalonic acid quantified in dried blood spots provides a precise, valid, and stable measure of functional vitamin B-12 status in healthy women.  

PubMed

Methylmalonic acid (MMA) is a sensitive and specific functional biomarker of vitamin B-12 status, commonly assessed in plasma or serum. Dried blood spots (DBSs) allow simpler and more cost-efficient blood sampling than plasma. To facilitate convenient testing for vitamin B-12 deficiency in large-scale surveys and in population groups from remote areas, we developed a method for MMA quantification in DBSs and tested its applicability as well as the long-term stability of MMA in DBSs at various temperatures. MMA was extracted from an 8-mm DBS punch with water:methanol (95:5, v:v) and methyl-d3-malonic acid as the internal standard. After sample cleanup by ultrafiltration and hexane extraction, MMA was quantified by using reversed-phase LC-tandem mass spectrometry. Extraction conditions were optimized to maximize the detection signal and achieve DBS extract concentrations above the lowest limit of quantification (signal-to-noise ratio ? 10) of 10 nmol/L. Recovery was between 93% and 96%. Intra- and interassay variation (CV%) for DBS MMA was 0.49% and 2.3%, respectively. Calibrators showed linearity (R(2) = 0.998) between 10 and 10,000 nmol/L. In 94 healthy women, MMA concentrations in DBS extract (min-max: 10.2-80.5 nmol/L) and plasma (min-max: 68-950 nmol/L) were correlated (? = 0.90) (P < 0.001). MMA concentrations in DBSs were stable at room temperature for 1 wk, in the refrigerator for 8 wk, and at -80°C for at least 1 y. This simple and robust method allows quantification of MMA in DBSs of healthy individuals. The linear relation between plasma and DBS MMA suggests that DBS MMA could predict plasma MMA, the current reference indicator for functional vitamin B-12 deficiency. With the advantages of minimally invasive specimen collection and no need for laborious blood processing steps, this method has the potential to be a reliable, convenient, and field-applicable alternative for assessment of vitamin B-12 status. PMID:25143369

Schroder, Theresa H; Quay, Teo A W; Lamers, Yvonne

2014-10-01

243

Cobryketone derived from vitamin B12 via palladium-catalyzed cleavage of the sp3-sp3 carbon-carbon bond.  

PubMed

Heptamethyl cobyrinate was transformed into hexamethyl 8-nor-cobyrinate. The crucial step involved the synthesis of new, vitamin B12 derived cobryketone via palladium-catalyzed cleavage of the sp(3)-sp(3) carbon-carbon bond with the liberation of the ketone. The replacement of sp(3) carbon atom with sp(2) (C?O) at the 8-position produces a bathochromic shift of all absorption bands and makes ? and ? bands equal as a consequence of the expansion of the existing conjugated system of double bonds. PMID:23544362

Kurco?, Sylwester; Proinsias, Keith ó; Gryko, Dorota

2013-04-19

244

Vitamin B6  

MedlinePLUS

... only vitamin B6, or vitamin B6 with other B vitamins, are also available. Am I getting enough vitamin ... Heart disease Some scientists had thought that certain B vitamins (such as folic acid, vitamin B12, and vitamin ...

245

Electronically Excited States of Vitamin B12: Benchmark Calculations Including Time-Dependent Density Functional Theory and Correlated Ab Initio Methods  

E-print Network

Time-dependent density functional theory (TD-DFT) and correlated ab initio methods have been applied to the electronically excited states of vitamin B12 (cyanocobalamin or CNCbl). Different experimental techniques have been used to probe the excited states of CNCbl, revealing many issues that remain poorly understood from an electronic structure point of view. Due to its efficient scaling with size, TD-DFT emerges as one of the most practical tools that can be used to predict the electronic properties of these fairly complex molecules. However, the description of excited states is strongly dependent on the type of functional used in the calculations. In the present contribution, the choice of a proper functional for vitamin B12 was evaluated in terms of its agreement with both experimental results and correlated ab initio calculations. Three different functionals, i.e. B3LYP, BP86, and LC-BLYP, were tested. In addition, the effect of relative contributions of DFT and HF to the exchange-correlation functional ...

Kornobis, Karina; Wong, Bryan M; Lodowski, Piotr; Jaworska, Maria; Andruniów, Tadeusz; Rudd, Kenneth; Kozlowski, Pawel M; 10.1021/jp110914y

2011-01-01

246

Immunohistochemical Quantification of the Vitamin B12 Transport Protein (TCII), Cell Surface Receptor (TCII-R) and Ki-67 in Human Tumor Xenografts  

PubMed Central

Background/Aim Cancer cells have an essential demand for vitamin B12 (cobalamin) to enable cellular replication. The present pilot study quantified the immunohistochemical expression of vitamin B12 transport protein (Transcobalamin II; TCII), cell surface receptor (Transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in human tumor xenografts. Materials and Methods Tissue microarray slides containing 34 xenograft tumor tissues were immunohistochemically stained using TCN2 (anti-TCII), CD320 (anti-TCII-R) and MIB-1 (anti-Ki-67) antibodies. Representatively stained areas of all slides were digitally imaged and protein expression was quantified using ImageJ software plugins. Results All xenograft tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Correlation between TCII/TCII-R and Ki-67 expression was not significant in xenograft tissues. Conclusion Proliferating cancer cells express measurable levels of TCII and TCII-R. Immunohistochemical quantification of these markers may be useful as a tool for detection of tumors, tailored selection of anti-tumor therapies and surveillance for evidence of recurrent disease. PMID:24122983

Sysel, Annette M.; Valli, Victor E.; Nagle, Ray B.; Bauer, Joseph A.

2014-01-01

247

Serum Level of Homocysteine, Folate and Vitamin-B12 in Epileptic Patients Under Carbamazepine and Sodium Valproate Treatment: A Systematic Review and Meta-Analysis  

PubMed Central

Background Numerous studies have shown that long term treatment with anticonvulsants may be an important risk factor for the onset of atherosclerosis, or worsening of its symptoms. There are many contradictory reports regarding these effects. Objectives We performed a systematic review and meta-analysis of the published studies in order to see whether the atherogenic outcomes could be related to any serum biochemical abnormalities. Materials and Methods Published articles indexed in PubMed, ISI web of science, Science Direct and Scopus databases from 1990 to 2011 were retrieved using a comprehensive search strategy. After omitting the unrelated articles and duplicates, articles met the eligibility criteria for critical appraisal were included in the analysis. Data were summarized in standard data abstraction forms and subjected to analysis by STATA software. Results Finally, ten published studies were included in the meta-analysis. Results showed that carbamazepine and sodium valproate consumption are associated with a significant elevation of the serum homocysteine levels. On the other hand, medication with carbamazepine is associated with a reduction of the level of folate in the serum and that of sodium valproate is associated with a reduction of serum level of vitamin B12. Conclusions According to the results of this study, as carbamazepine and valproate sodium consumption can result in elevated serum levels of homocysteine and decreased levels of folate and vitamin B12, and the atherogenic effect of increased serum homocysteine level is well established, the patients under these medications should be monitored for possible atherogenic effects. PMID:23984007

Gorjipour, Fazel; Asadi, Yasin; K. Osguei, Nushin; Effatkhah, Marjan; Samadikuchaksaraei, Ali

2013-01-01

248

Control of prostate cancer associated with withdrawal of a supplement containing folic acid, L-methyltetrahydrofolate and vitamin B12: a case report  

PubMed Central

Introduction This is the first report of possible direct stimulation of hormone-resistant prostate cancer or interference of docetaxel cytotoxicity of prostate cancer in a patient with biochemical relapse of prostatic-specific antigen. This observation is of clinical and metabolic importance, especially at a time when more than 80 countries have fortified food supplies with folic acid and some contemplate further fortification with vitamin B12. Case presentation Our patient is a 71-year-old Caucasian man who had been diagnosed in 1997 with prostate cancer, stage T1c, and Gleason score 3+4 = 7. His primary treatment included intermittent androgen deprivation therapy including leuprolide + bicalutamide + deutasteride, ketoconazole + hydrocortisone, nilandrone and flutamide to resistance defined as biochemical relapse of PSA. While undergoing docetaxel therapy to treat a continually increasing prostate-specific antigen level, withdrawal of 10 daily doses of a supplement containing 500 ?g of vitamin B12 as cyanocobalamin, as well as 400 ?g of folic acid as pteroylglutamic acid and 400 ?g of L-5-methyltetrahydrofolate for a combined total of 800 ?g of mixed folates, was associated with a return to a normal serum prostatic-specific antigen level. Conclusion This case report illustrates the importance of the effects of supplements containing large amounts of folic acid, L-5-methyltetrahydrofolate, and cyanocobalamin on the metabolism of prostate cancer cells directly and/or B vitamin interference with docetaxel efficacy. Physicians caring for patients with prostate cancer undergoing watchful waiting, hormone therapy, and/or chemotherapy should consider the possible acceleration of tumor growth and/or metastasis and the development of drug resistance associated with supplement ingestion. We describe several pathways of metabolic and epigenetic interactions that could affect the observed changes in serum levels of prostate-specific antigen. PMID:21867542

2011-01-01

249

The effect of vitamin B 12 and various levels of iodine in the diet of growing chicks and mature hens  

E-print Network

THF. EFFEC'I OF VITAMIN 8, , AND VARIOUS EKVK Lo OF IODINE IN THE DIET OF GBOV. ING CHICKS AND MAT URE HENS EDV ABD MACK SANTA A 'I'HgoIS oubmitted to tbe Gt aduate ochooi of tbe Agricultural and hiecbanical College of f'"xae in pertial fulf...Hhnent of tbe retlufremcnte for tbe dogree MASTER OF oCII. NCE ht a j o r oubject: sultry ociencc August 1957 'I HE E FFECT OF VITAMIN 9 . AND VABIUU& cEV E 1 o 12 OF IODINE IN THE DIET C F GI'On ING CHICKS AND MA'l UHE HENS A THEnle t DV. AND MAC K BA N...

Banta, Edward Mack

2012-06-07

250

Vitamin B12, antibiotics and unidentified factors in the nutrition of the turkey poult and mature chicken  

E-print Network

of microorganisms snd sn increase in the enterococci of the intestine, The sdm1nistrstion of penic1111n either orally or in]acted '1 -resulted in s marked increase in the number of penicillin resistant organisms. This work wss carried out on vitamin depleted... on the Intestinal flora of the fowl. When these facts were considered it seemed desirable to determine the effect oi' several antibiotics when tested undez' the same conditions on the growth rate in the turkey poult. Since the mode of action of these substances...

Reid, Bobby Leroy

1952-01-01

251

Drug release profiles and microstructural characterization of cast and freeze dried vitamin B12 buccal films by positron annihilation lifetime spectroscopy.  

PubMed

Solvent cast and freeze dried films, containing the water-soluble vitamin B12 as model drug were prepared from two polymers, sodium alginate (SA), and Carbopol 71G (CP). The proportion of the CP was changed in the films. The microstructural characterization of various samples was carried out by positron annihilation lifetime spectroscopy (PALS). The drug release kinetics of untreated and stored samples was evaluated by the conventionally applied semi-empirical power law. Correlation was found between the changes of the characteristic parameters of the drug release and the ortho-positronium (o-Ps) lifetime values of polymer samples. The results indicated that the increase of CP concentration, the freeze-drying process and the storage at 75% R.H. decreased the rate of drug release. The PALS method enabled the distinction between the micro- and macrostructural factors influencing the drug release profile of polymer films. PMID:24269613

Szabó, Barnabás; Kállai, Nikolett; Tóth, Gerg?; Hetényi, Gergely; Zelkó, Romána

2014-02-01

252

Neoproterozoic Oxygenation of Earth Surface Environments Reflected in the Late Evolution of the O2-Dependent Vitamin B12 Biosynthesis Pathway  

NASA Astrophysics Data System (ADS)

There are multiple lines of evidence for a significant rise of O2 in the Earth's atmosphere ~2.4 Ga. A second oxygenation event in the Neoproterozoic is not as well constrained. These changes in environmental redox affected the abundances of bioessential elements. Trace elements such as Co, Fe, and Ni were likely favored in the early evolution of metalloenzymes, prior to the first oxidation event. Consistent with this expectation, vitamin B12 is a Co-containing biomolecule whose biosynthesis is thought to have evolved prior to the origin of oxygenic photosynthesis and the first rise in O2. However, biochemical characterization of the many enzymes involved in B12 biosynthesis has revealed two distinct pathways: an O2-independent pathway and an O2-dependant pathway. The major difference between these pathways involves the timing of the insertion of Co. We examined the amino acid sequences of enzymes in the B12 biosynthesis pathway from a set of 100 phylogenetically diverse microbial genomes, focusing on enzymes exclusive to each pathway as well as enzymes shared by both. Molecular clock and phylogenetic analyses were performed on alignments of the sequences obtained from these study genomes. This approach focused on functional genes rather than the phylogeny of microbes in an attempt to understand the evolution of the pathway itself, rather than its presence in individual phylogenetic groups. Clear differences in age are apparent between representatives of each pathway. The O2-independent pathway and enzymes shared in both pathways show the most ancient last common ancestors. In contrast, the enzymes associated exclusively with the O2-dependent pathway diverged from a common ancestor less than a billion years ago. Phylogenetic analysis suggests that these enzymes were recruited from other biochemical pathways. From these results it seems likely that the evolution of the O2-dependent pathway occurred long after the initial evolution of the B12 biosynthesis. This conclusion provides evidence independent of the geological record as to the timing and existence of a second great oxidation event in Earth history.

Saito, M. A.; Bertrand, E. M.; Anbar, A.

2008-12-01

253

Calcidiol and vitamin D binding protein uptake by LLC-PK/sub 1/ cells  

SciTech Connect

The process by which target cells take up vitamin D and its metabolites is not known. The authors studied the uptake of both /sup 3/H-calcidiol and /sup 125/I-Vitamin D Binding Protein (DBP) by LLC-PK/sub 1/ cells. Uptake was directly related to their extracellular concentrations. In the presence of 55 serum in the growth media cells previously incubated with 10 nM calcitriol for 4 hr had a greater uptake of calcidiol than those cells not incubated with calcitriol. This effect of calcitriol on calcidiol uptake was absent when cells were grown in hormone-supplemented, serum-free media, despite these cells having a cytosolic calcitriol receptor. Equal uptake of calcidiol occurred when DBP was absent and when DBP was present in a one to one molar ratio to calcidiol. With a 1:1 ratio of DBP to calcidiol and a measured K/sub D/ of 2 x 10/sup -8/M, the uptake of calcidiol could not be accounted for by uptake of the free ligand alone. A large excess of DBP (100:1) in relation to calcidiol suppressed uptake of calcidiol by approx. 90%. The authors have not been able to identify a saturable, specific uptake of either calcidiol or DBP despite DBP appearing to facilitate calcidiol uptake.

Keenan, M.J.; Holmes, R.P.

1986-03-01

254

Comparison of two modes of vitamin B12 supplementation on neuroconduction and cognitive function among older people living in Sandiago, Chile: A cluster randomized controlled trial. A study protocol(ISRCTN 02694183)  

Technology Transfer Automated Retrieval System (TEKTRAN)

BACKGROUND: Older people have a high risk of vitamin B12 deficiency; this can lead to varying degrees of cognitive and neurological impairment. CBL deficiency may present as macrocytic anemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older peo...

255

Expression of Genes Encoding Enzymes Involved in the One Carbon Cycle in Rat Placenta is Determined by Maternal Micronutrients (Folic Acid, Vitamin B12) and Omega-3 Fatty Acids  

PubMed Central

We have reported that folic acid, vitamin B12, and omega-3 fatty acids are interlinked in the one carbon cycle and have implications for fetal programming. Our earlier studies demonstrate that an imbalance in maternal micronutrients influence long chain polyunsaturated fatty acid metabolism and global methylation in rat placenta. We hypothesize that these changes are mediated through micronutrient dependent regulation of enzymes in one carbon cycle. Pregnant dams were assigned to six dietary groups with varying folic acid and vitamin B12 levels. Vitamin B12 deficient groups were supplemented with omega-3 fatty acid. Placental mRNA levels of enzymes, levels of phospholipids, and glutathione were determined. Results suggest that maternal micronutrient imbalance (excess folic acid with vitamin B12 deficiency) leads to lower mRNA levels of methylene tetrahydrofolate reductase (MTHFR) and methionine synthase , but higher cystathionine b-synthase (CBS) and Phosphatidylethanolamine-N-methyltransferase (PEMT) as compared to control. Omega-3 supplementation normalized CBS and MTHFR mRNA levels. Increased placental phosphatidylethanolamine (PE), phosphatidylcholine (PC), in the same group was also observed. Our data suggests that adverse effects of a maternal micronutrient imbalanced diet may be due to differential regulation of key genes encoding enzymes in one carbon cycle and omega-3 supplementation may ameliorate most of these changes. PMID:25003120

Khot, Vinita; Kale, Anvita; Joshi, Asmita; Chavan-Gautam, Preeti; Joshi, Sadhana

2014-01-01

256

Pulse radiolysis studies of the reactions of nitrogen dioxide with the vitamin B12 complexes cob(II)alamin and nitrocobalamin.  

PubMed

Although now recognized to be an important reactive nitrogen species in biological systems that modifies the structures of proteins, DNA and lipids, there are few studies on the reactivity of NO2, including the reactions between NO2 and transition metal complexes. We report kinetic studies on the reactions of NO2 with two forms of vitamin B12 - cob(II)alamin and nitrocobalamin. UV-visible spectroscopy and HPLC analysis of the product solution show that NO2 cleanly oxidizes the metal center of cob(II)alamin to form nitrocobalamin, with a second-order rate constant of (3.5±0.3)×10(8)M(-1)s(-1) (pH7.0 and 9.0, room temperature, I=0.20M). The stoichiometry of the reaction is 1:1. No reaction is detected by UV-visible spectroscopy and HPLC analysis of the product solution when nitrocobalamin is exposed to up to 2.0molequiv. NO2. PMID:25450018

Dassanayake, Rohan S; Cabelli, Diane E; Brasch, Nicola E

2014-10-01

257

Biosynthesis of vitamin B12: the preparative multi-enzyme synthesis of precorrin-3A and 20-methylsirohydrochlorin (a 2,7,20-trimethylisobacteriochlorin).  

PubMed Central

The Bacillus subtilis genes hemB, hemC and hemD, encoding respectively the enzymes porphobilinogen synthase, hydroxymethylbilane synthase and uroporphyrinogen III synthase, have been expressed in Escherichia coli using a single plasmid construct. An enzyme preparation from this source converts 5-aminolaevulinic acid (ALA) preparatively and in high yield into uroporphyrinogen III. The Pseudomonas denitrificans genes cobA and cobI, encoding respectively the enzymes S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase (SUMT) and S-adenosyl-L-methionine:precorrin-2 methyltransferase (SP2MT), were also expressed in E. coli. When SUMT was combined with the coupled-enzyme system that produces uroporphyrinogen III, precorrin-2 was synthesized from ALA, and when SP2MT was also added the product from the coupling of five enzymes was precorrin-3A. Both of these products are precursors of vitamin B12, and they can be used directly for biosynthetic experiments or isolated as their didehydro octamethyl esters in > 40% overall yield. The enzyme system which produces precorrin-3A is sufficiently stable to allow long incubations on a large scale, affording substantial quantities (15-20 mg) of product. PMID:8546704

Stamford, N P; Crouzet, J; Cameron, B; Alanine, A I; Pitt, A R; Yeliseev, A A; Battersby, A R

1996-01-01

258

Intricacies of Redoxome Function Demonstrated with a Simple In vitro Chemiluminescence Method, with Special Reference to Vitamin B12 as Antioxidant  

PubMed Central

The homeostatic control of the redox system (the redoxome) in mammalian cells depends upon a large number of interacting molecules, which tend to buffer the electronegativity of cells against oxidants or reductants. Some of these components kill – at high concentration – microbes and by-stander normal cells, elaborated by professional phagocytes. We examined whether a simple, in vitro chemiluminescence set-up, utilizing redox components from human polymorphonuclear neutrophils (PMN) and red blood cells (RBC), could clarify some unexplained workings of the redoxome. PMN or purified myeloperoxidase (MPO) triggers formation of reactive oxygen species (ROS), quantified by light emission from oxidized luminol. Both PMN and RBC can generate abundant amounts of ROS, necessitating the presence of a high-capacity redoxome to keep the cellular electronegativity within physiological limits. We obtained proof-of-principle evidence that our assay could assess redox effects, but also demonstrated the intricacies of redox reactions. Simple dose–responses were found, as for the PMN proteins S100A9 (A9) and S100A8 (A8), and the system also revealed the reducing capacity of vitamin B12 (Cbl) and lutein. However, increased concentrations of oxidants in the assay mixture could decrease the chemiluminescence. Even more remarkable, A9 and NaOCl together stimulated the MPO response, but alone they inhibited MPO chemiluminescence. Biphasic responses were also recorded for some dose–response set-ups and are tentatively explained by a ‘balance hypothesis’ for the redoxome. PMID:25345916

Bøyum, A; Forstrøm, R J; Sefland, I; Sand, K L; Benestad, H B

2014-01-01

259

An unblinded, randomised phase II study of platinum-based chemotherapy with vitamin B12 and folic acid supplementation in the treatment of lung cancer with plasma homocysteine blood levels as a biomarker of severe neutropenic toxicity  

PubMed Central

Background Vitamin B12 and folic acid (referred to as vitamin supplementation) improves the toxicity profile of pemetrexed containing regimens. Low baseline vitamin B12 and folate levels are reflected in a raised total homocysteine level (HC). Studies have suggested that pretreatment HC levels predict neutropenia toxicity. We have tested supplementation with vitamin B12 and folate in non-pemetrexed platinum-based regimens to decrease treatment-related toxicity and looked for a correlation between toxicity and change in homocysteine levels. Patient and method Eighty-three patients with advanced lung cancer and malignant mesothelioma were randomly assigned to receive platinum-based chemotherapy with (arm A) or without (arm B) vitamin B12 and folic acid supplementation. The primary end point was grade 3/4 neutropenia and death within 30?days of treatment. Secondary end points included quality of life, overall survival (OS) and the relationship between baseline and post supplementation HC levels and toxicity. Results In the intention-to-treat population, no significant difference was seen between the two groups with respect to chemotherapy-induced grade 3/4 neutropenia and death within 30?days of chemotherapy (36% vs 37%; p=0.966, emesis (2% vs 6%; p=0.9) or OS (12.3?months vs 7?months; p=0.41). There was no significant difference in survival rates by baseline HC level (p=0.9). Decrease in HC with vitamin supplementation was less frequent than expected. High baseline HC levels decreased with vitamin supplementation in only 9/36 (25%) patients (successful supplementation). Post hoc analysis showed that patients in arm A who were successfully supplemented (9/36=25%) had less neutropenic toxicity (0% vs 69%; p=0.02) compared to unsupplemented patients. Conclusions The addition of vitamin B12 and folic acid to platinum-containing regimens did not overall improve the toxicity, quality of life or OS. Rates of grade 3/4 neutropenia at 36/37% was as predicted. Further studies to increase the rate of successful supplementation and to further test the biomarker potential of post supplementation HC levels in predicting chemotherapy-induced neutropenia in platinum-based chemotherapy are warranted. Trial registration number: EudracCT 2005-002736-10 ISRCTN8734355. PMID:25553247

Minchom, A R; Saksornchai, K; Bhosle, J; Gunapala, R; Puglisi, M; Lu, S K; Nimako, K; Coward, J; Yu, K C; Bordi, P; Popat, S; O'Brien, M E R

2014-01-01

260

Lecithin:Retinol Acyltransferase Is Critical for Cellular Uptake of Vitamin A from Serum Retinol-binding Protein*  

PubMed Central

Vitamin A (all-trans-retinol) must be adequately distributed within the mammalian body to produce visual chromophore in the eyes and all-trans-retinoic acid in other tissues. Vitamin A is transported in the blood bound to retinol-binding protein (holo-RBP), and its target cells express an RBP receptor encoded by the Stra6 (stimulated by retinoic acid 6) gene. Here we show in mice that cellular uptake of vitamin A from holo-RBP depends on functional coupling of STRA6 with intracellular lecithin:retinol acyltransferase (LRAT). Thus, vitamin A uptake from recombinant holo-RBP exhibited by wild type mice was impaired in Lrat?/? mice. We further provide evidence that vitamin A uptake is regulated by all-trans-retinoic acid in non-ocular tissues of mice. When in excess, vitamin A was rapidly taken up and converted to its inert ester form in peripheral tissues, such as lung, whereas in vitamin A deficiency, ocular retinoid uptake was favored. Finally, we show that the drug fenretinide, used clinically to presumably lower blood RBP levels and thus decrease circulating retinol, targets the functional coupling of STRA6 and LRAT to increase cellular vitamin A uptake in peripheral tissues. These studies provide mechanistic insights into how vitamin A is distributed to peripheral tissues in a regulated manner and identify LRAT as a critical component of this process. PMID:22637576

Amengual, Jaume; Golczak, Marcin; Palczewski, Krzysztof; von Lintig, Johannes

2012-01-01

261

Vitamins  

MedlinePLUS

... and folate) Vitamin C Vitamin D Vitamin E Vitamin K You can usually get all your vitamins from ... foods you eat. Your body can also make vitamins D and K. People who eat a vegetarian diet may need ...

262

Methyl Vitamin B12 but not methylfolate rescues a motor neuron-like cell line from homocysteine-mediated cell death  

SciTech Connect

Homocysteine is an excitatory amino acid implicated in multiple diseases including amyotrophic lateral sclerosis (ALS). Information on the toxicity of homocysteine in motor neurons is limited and few studies have examined how this toxicity can be modulated. In NSC-34D cells (a hybrid cell line derived from motor neuron-neuroblastoma), homocysteine induces apoptotic cell death in the millimolar range with a TC{sub 50} (toxic concentration at which 50% of maximal cell death is achieved) of 2.2 mM, confirmed by activation of caspase 3/7. Induction of apoptosis was independent of short-term reactive oxygen species (ROS) generation. Methyl Vitamin B12 (MeCbl) and methyl tetrahydrofolate (MTHF), used clinically to treat elevated homocysteine levels, were tested for their ability to reverse homocysteine-mediated motor neuron cell death. MeCbl in the micromolar range was able to provide neuroprotection (2 h pretreatment prior to homocysteine) and neurorescue (simultaneous exposure with homocysteine) against millimolar homocysteine with an IC{sub 50} (concentration at which 50% of maximal cell death is inhibited) of 0.6 {mu}M and 0.4 {mu}M, respectively. In contrast, MTHF (up to 10 {mu}M) had no effect on homocysteine-mediated cell death. MeCbl inhibited caspase 3/7 activation by homocysteine in a time- and dose-dependent manner, whereas MTHF had no effect. We conclude that MeCbl is effective against homocysteine-induced cell death in motor neurons in a ROS-independent manner, via a reduction in caspase activation and apoptosis. MeCbl decreases Hcy induced motor neuron death in vitro in a hybrid cell line derived from motor neuron-neuroblastoma and may play a role in the treatment of late stage ALS where HCy levels are increased in animal models of ALS.

Hemendinger, Richelle A., E-mail: richelle.hemendinger@carolinashealthcare.org; Armstrong, Edward J.; Brooks, Benjamin Rix

2011-03-15

263

[Circadian rhythm disturbance after radiotherapy for brain tumor in infantile period--clinical effect of L-thyroxine and vitamin B12].  

PubMed

We reported here 19-year-old man suffering from circadian sleep-wake (S-W) rhythm disturbance after total tumor resection and whole brain irradiation. This 19-year-old man was diagnosed as having astrocytoma in the right temporal lobe by CT scan and angiography at the age of 6 months. After total tumor resection and whole brain irradiation (60Co 60 Gy), he showed profound psychomotor retardation, endocrinologic dysfunction including hypothyroidism and growth hormone deficiency, and sleep-wake rhythm disturbance. At the age of 19, brain MRI revealed asymmetrical low intensity in the hypothalamic region. On endocrinological examination panhypopituitarism due to primary hypothalamic lesion was evident. His S-W rhythm was disturbed showing a dispersed type sleep, i.e., sleep periods were dispersedly distributed throughout the 24 hours. So he showed a lethargic tendency in the daytime. All-day polysomnography revealed abnormal sleep structure such as the absence of sleep spindle and hump, peripheral apnea, snoring and low oxygen saturation. After L-thyroxine supplementation his daily activity improved gradually. The decrease in short time sleep and tendency of a free-running rhythm were observed and oxygen saturation improved remarkably. Peripheral apnea and snoring disappeared. The wakening effect of L-thyroxine administration may be due to improvement of hypothyroidism symptom such as myxoedematous pharynx. In addition, it seems related to the alteration of the central S-W rhythm regulation, because free-running rhythm appeared after L-thyroxine administration. Vitamin B12 (VB12), which has been reported to be effective for sleep-wake rhythm disorders, was not effective for our patient's free-running rhythm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8217401

Kubota, M; Shinozaki, M; Sasaki, H

1993-08-01

264

Superoxide-dependent uptake of vitamin C in human glioma cells.  

PubMed

Glioblastomas are lethal brain tumors that resist current cytostatic therapies. Vitamin C may antagonize the effects of reactive oxygen species (ROS) generating therapies; however, it is often used to reduce therapy-related side effects despite its effects on therapy or tumor growth. Because the mechanisms of vitamin C uptake in gliomas are currently unknown, we evaluated the expression of the sodium-vitamin C cotransporter (SVCT) and facilitative hexose transporter (GLUT) families in human glioma cells. In addition, as microglial cells can greatly infiltrate high-grade gliomas (constituting up to 45% of cells in glioblastomas), the effect of TC620 glioma cell interactions with microglial-like HL60 cells on vitamin C uptake (Bystander effect) was determined. Although glioma cells expressed high levels of the SVCT isoform-2 (SVCT2), low functional activity, intracellular localization and the expression of the dominant-negative isoform (dnSVCT2) were observed. The increased glucose metabolic activity of glioma cells was evident by the high 2-Deoxy-d-glucose and dehydroascorbic acid (DHA) uptake rates through the GLUT isoform-1 (GLUT1), the main DHA transporter in glioblastoma. Co-culture of glioma cells and activated microglial-like HL60 cells resulted in extracellular ascorbic acid oxidation and high DHA uptake by glioma cells. This Bystander effect may explain the high antioxidative potential observed in high-grade gliomas. This study strongly suggests that the Bystander effect, that is, glioma cell interaction with oxidant-producing microglia, could be an important mechanism for glioma vitamin C loading in the absence of functional sodium-vitamin C cotransporter 2 (SVCT2) expression. The high cellular vitamin C load in glioma cells results from a high uptake of extracellular dehydroascorbic acid (DHA) generated by neighboring microglia. This Bystander effect may explain the high antioxidative potential observed in high-grade gliomas, considering that high-grade gliomas may be the only neoplasm where oxidant-producing microglia can almost equal the number of tumor cells. PMID:23859461

Rodríguez, Federico S; Salazar, Katterine A; Jara, Nery A; García-Robles, María A; Pérez, Fernando; Ferrada, Luciano E; Martínez, Fernando; Nualart, Francisco J

2013-12-01

265

A novel spectral resolution and simultaneous determination of multicomponent mixture of Vitamins B1, B6, B12, Benfotiamine and Diclofenac in tablets and capsules by derivative and MCR-ALS.  

PubMed

A novel method was developed for spectral resolution and further determination of five-component mixture including Vitamin B complex (B1, B6, B12 and Benfotiamine) along with the commonly co-formulated Diclofenac. The method is simple, sensitive, precise and could efficiently determine the five components by a complementary application of two different techniques. The first is univariate second derivative method that was successfully applied for determination of Vitamin B12. The second is Multivariate Curve Resolution using the Alternating Least Squares method (MCR-ALS) by which an efficient resolution and quantitation of the quaternary spectrally overlapped Vitamin B1, Vitamin B6, Benfotiamine and Diclofenac sodium were achieved. The effect of different constraints was studied and the correlation between the true spectra and the estimated spectral profiles were found to be 0.9998, 0.9983, 0.9993 and 0.9933 for B1, B6, Benfotiamine and Diclofenac, respectively. All components were successfully determined in tablets and capsules and the results were compared to HPLC methods and they were found to be statistically non-significant. PMID:25645231

Hegazy, Maha A; Abdelwahab, Nada S; Fayed, Ahmed S

2015-04-01

266

THE INFLUENCE OF TRACE-MINERALIZE D SALT UPON THE VITAMIN B12 AND FOLIC ACID CONTENT OF GOAT'S MILK 1  

Microsoft Academic Search

was observed to be 4.2 ~, per liter immediately following parturition and was observed to drop rapidly to the low level of 0.18 ~ per liter after 3 weeks. Since Harper, Richard and Collins (3) reported that the vitamin BI_~ level of ewe's milk could be increased by the addition of cobalt or trace-minerals (containing cobalt) to the ewe's diet,

R. A. COLLINS; E. BOLDT; A. ELVEHJEM; E. B. HART

267

Biosynthesis and uptake of thiamine (vitamin B1) in bloodstream form Trypanosoma brucei brucei and interference of the vitamin with melarsen oxide activity.  

PubMed

Bloodstream forms of Trypanosoma brucei brucei were cultivated in the presence and absence of thiamine (vitamin B1) and pyridoxine (vitamin B6). The vitamins do not change growth behaviour, indicating that Trypanosoma brucei is prototrophic for the two vitamins even though in silico no bona-fide thiamine-biosynthetic genes could be identified in the T. brucei genome. Intracellularly, thiamine is mainly present in its diphosphate form. We were unable to detect significant uptake of [3H]thiamine and structural thiamine analogues such as pyrithiamine, oxithiamine and amprolium were not toxic for the bloodstream forms of T. brucei, indicating that the organism does not have an efficient uptake system for thiamine and its analogues. We have previously shown that, in the fission yeast Saccharomyces pombe, the toxicity of melarsen oxide, the pharmacologically active derivative of the frontline sleeping sickness drug melarsoprol, is abolished by thiamine and the drug is taken up by a thiamine-regulated membrane protein which is responsible for the utilization of thiamine. We show here that thiamine also has weak effects on melarsen oxide-induced growth inhibition and lysis in T. brucei. These effects were consistent with a low affinity of thiamine for the P2 adenosine transporter that is responsible for uptake of melaminophenyl arsenicals in African trypanosomes. PMID:16375907

Stoffel, Sabine A; Rodenko, Boris; Schweingruber, Anne-Marie; Mäser, Pascal; de Koning, Harry P; Schweingruber, M Ernst

2006-02-01

268

Neurologic aspects of cobalamin (B12) deficiency.  

PubMed

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. Particularly important for optimal functioning of the nervous system is cobalamin (vitamin B12). Cobalamin deficiency is particularly common in the elderly and after gastric surgery. Many patients with clinically expressed cobalamin deficiency have intrinsic factor-related malabsorption such as that seen in pernicious anemia. The commonly recognized neurological manifestations of cobalamin deficiency include a myelopathy with or without an associated neuropathy. This review deals with neurological aspects of vitamin B12 deficiency and attempts to highlight recent developments. PMID:24365360

Kumar, Neeraj

2014-01-01

269

Uptake of /sup 75/Se-selenite by brush border membrane vesicles from chick duodenum stimulated by vitamin D  

SciTech Connect

Brush border membrane vesicles were isolated from mucosal homogenates of duodena from normal, rachitic and vitamin D-treated rachitic chicks using a discontinuous sucrose gradient, and further purified by glycerol gradient centrifugation. In vitro uptake of 75Se-selenite by purified brush border membrane vesicles was studied using a rapid filtration technique. The time course of 75Se uptake was non-linear; rapid initial binding was followed by a gradual decrease in the rate of uptake until an equilibrium value was reached at 60-120 min. The initial binding at 36 s was not affected by selenite concentration in the incubation buffer, while the fractional rate of uptake between the 36 s and 2 min time periods was clearly lower with 1 mM Se than with 4-100 microM Se. 75Se uptake did not show any dependency on the external Na-gradient, nor could it be inhibited by other anions (arsenate, phosphate). Treatment of rachitic chicks either with cholecalciferol (500 Iu, 72 h) or with 1,25(OH)2-cholecalciferol (0.5 microgram given 16 h prior to isolation of the vesicles) significantly enhanced 75Se uptake. A threefold excess of mannitol in the outside buffer reduced 75Se uptake by vesicles from vitamin D-deficient and D-treated chicks 60% and 35% respectively, but had no effect on vesicles from vitamin D-treated chicks preloaded with 75Se. Neither saponin treatment nor excess cold selenite could release the label from the vesicles preloaded with 75Se. These data are compatible with the hypothesis that selenite easily crosses the brush border membrane into the intravesicular space and, once inside, is tightly bound by the membrane.

Mykkanen, H.M.; Wasserman, R.H.

1989-02-01

270

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B6, B12, D, and E  

PubMed Central

A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids, and polyphenols. Recommendations are given regarding which methods are most justified for answering bioaccessibility or bioavailability related questions for specific nutrients. The need for more validation studies in which in vivo results are compared to in vitro results is also discussed. PMID:22934067

Etcheverry, Paz; Grusak, Michael A.; Fleige, Lisa E.

2012-01-01

271

Intestinal absorption of vitamins.  

PubMed

This article provides an overview of advances in understanding the cellular and molecular mechanisms and regulation of intestinal absorption processes of vitamins. The vitamins covered are the water-soluble vitamins folic acid, cobalamin (vitamin B12), biotin, pantothenic acid, and thiamine (vitamin B1) and the lipid-soluble vitamin A. For folate, significant advances have been made in regard to i) digestion of dietary folate polyglutamates to folate monoglutamates by the cloning of the responsible enzyme; ii) identification of the cDNA responsible for the intestinal folate transporter; iii) delineation of intracellular mechanisms that regulate small intestinal folate uptake; and iv) identification and characterization of a specific, pH-dependent, carrier-mediated system for folate uptake at the luminal (apical) membrane of human colonocytes. Studies on cobalamine have focused on cellular and molecular characterization of the intrinsic factor and its receptor. Studies on biotin transport in the small intestine have shown that the uptake process is shared by another water-soluble vitamin, pantothenic acid. Furthermore, a Na-dependent, carrier-mediated biotin uptake system that is also shared with pantothenic acid has been identified at the apical membrane of human colonocytes. This carrier is believed to be responsible for the absorption of the bacterially synthesized biotin and pantothenic acid in the large intestine. Also, preliminary studies have reported the cloning of a biotin transporter from the small intestine. As for thiamine intestinal transport, a study has shown thiamine uptake by small intestinal biopsy specimens to be via a carrier-mediated, Na-independent mechanism, which appears to be up-regulated in thiamine deficiency. Studies on vitamin A intestinal absorption have shown the existence of a receptor-mediated mechanism for the uptake of retinol bound to retinol-binding protein in the small intestine of suckling rats. Another study has shown that retinoic acid increases the mRNA level of the cellular retinol binding protein II and the rate of retinol uptake by Caco-2 intestinal epithelial cells. The study suggested that retinoids may play a role in the regulation of vitamin A intestinal absorption. PMID:17023940

Said, H M; Kumar, C

1999-03-01

272

Associations between vitamin D-binding protein isotypes, circulating 25(OH)D levels, and vitamin D metabolite uptake in colon cancer cells.  

PubMed

Vitamin D metabolites have been extensively studied as cancer chemopreventive agents. Gc-globulin (GC) isotypes, based on rs7041 and rs4588 diplotypes, have varying affinities for 1?,25-dihydroxyvitamin D (1,25(OH)2D) and 25-hydroxyvitamin D (25(OH)D), which may affect circulating metabolite concentration as well as delivery at the cellular level. We evaluated associations between GC isotype and circulating vitamin D metabolite concentrations in 403 ursodeoxycholic acid (UDCA) clinical trial participants. Metabolite uptake was evaluated in human colon cancer (HCT-116) cells treated with ethanol vehicle, 1,25(OH)2D, or 25(OH)D, and with plasma from individuals with known GC isotype. Mammalian-2-hybrid and vitamin D-responsive element-based luciferase assays were used to measure the vitamin D receptor pathway activation as a marker for metabolite uptake. Regression analysis demonstrated significantly lower serum 25(OH)D concentration for clinical trial participants with 1F_2, 1S_2, or 2_2 isotypes (P < 0.01) compared with 1S_1S. Consistent with these in vivo observations, cellular data revealed that 25(OH)D uptake varied less by GC isotype only at the higher concentration tested (P = 0.05), while 1,25(OH)2D uptake differed markedly by GC isotype across concentration and assay (P < 0.01). The 1F_1S and 1F_2 isotypes produced the greatest reporter gene induction with 1,25(OH)2D treatment and, while activation varied less with 25(OH)D, the 2_2 isotype demonstrated increased induction at the lower concentration. These results suggest that vitamin D metabolite concentration and delivery to colon cells may vary not only by GC isotype, but also that certain isotypes may more effectively deliver 1,25(OH)2D versus 25(OH)D. Overall, these results may help identify populations at risk for cancer and potential recipients of targeted chemoprevention. PMID:24472850

Hibler, Elizabeth A; Jacobs, Elizabeth T; Stone, Angelika Dampf; Sardo, Christine L; Galligan, Michael A; Jurutka, Peter W

2014-04-01

273

Vitamin E TPGS coated liposomes enhanced cellular uptake and cytotoxicity of docetaxel in brain cancer cells.  

PubMed

The aim of this work was to develop a drug delivery system of liposomes, which are coated with D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS), a PEGylated vitamin E, with docetaxel as a model drug for enhanced treatment of brain tumour in comparison with the nude liposomes as well as with the so-called stealth liposomes, i.e. those coated with polyethylene glycol (PEG), which have been intensive investigated in the literature. Docetaxel or coumarin-6 loaded liposomes were prepared by the solvent injection method and characterized for their particle size, polydispersity, zeta potential and drug encapsulation efficiency. C6 glioma cells were employed as an in vitro model to access cellular uptake and cytotoxicity of the drug or coumarin-6 loaded liposomes. The particle size of the PEG or TPGS coated liposomes was ranged between 126 and 191nm. High-resolution field-emission transmission electron microscopy (FETEM) confirmed the coating of TPGS on the liposomes. The IC50 value, which is the drug concentration needed to kill 50% cells in a designated time period, was found to be 37.04±1.05, 31.04±0.75, 7.70±0.22, and 5.93±0.57?g/ml for the commercial Taxotere(®), the nude, PEG coated and TPGS coated liposomes, respectively after 24h culture with C6 glioma cells. The TPGS coated liposomes showed great advantages in vitro than the PEG coated liposomes. PMID:22001537

Muthu, Madaswamy S; Kulkarni, Sneha A; Xiong, Jiaqing; Feng, Si-Shen

2011-12-15

274

Uptake and degradation of filamentous actin and vitamin D-binding protein in the rat.  

PubMed Central

Tissue uptake and degradation of 125I-tyramine-cellobiose-labelled filamentous actin, vitamin D-binding protein (DBP) and actin-DBP complex were studied in the rat. Actin and actin-DBP complex were cleared from plasma at a faster rate than was DBP. About 40% of injected actin was recovered in the liver between 10 and 30 min after administration. Of the total radioactivity recovered in the liver, about 35% and 40% was detected in parenchymal and endothelial cells respectively when labelled actin or DBP-actin complex was injected intravenously. When labelled DBP alone was injected, approx. 55% of the radioactivity recovered in liver was in the Kupffer cells. These results suggest that actin is targeting the DBP-actin complex to the endothelial and parenchymal liver cells. Filamentous actin was also taken up in large amounts and at a rapid rate in parenchymal as well as non-parenchymal liver cells in vitro. Our data indicate that the rat has a mechanism to clear actin and the DBP-actin complex from plasma and that both parenchymal and non-parenchymal liver cells are involved in this process. PMID:2001239

Dueland, S; Nenseter, M S; Drevon, C A

1991-01-01

275

Differential regulation of hepatic transcription factors in the Wistar rat offspring born to dams fed folic acid, vitamin B12 deficient diets and supplemented with omega-3 fatty acids.  

PubMed

Nutritional status of the mother is known to influence various metabolic adaptations required for optimal fetal development. These may be mediated by transcription factors like peroxisome proliferator activated receptors (PPARs), which are activated by long chain polyunsaturated fatty acids. The objective of the current study was to examine the expression of different hepatic transcription factors and the levels of global methylation in the liver of the offspring born to dams fed micronutrient deficient (folic acid and vitamin B12) diets and supplemented with omega-3 fatty acids. Female rats were divided into five groups (n = 8/group) as follows; control, folic acid deficient (FD), vitamin B12 deficient (BD) and omega-3 fatty acid supplemented groups (FDO and BDO). Diets were given starting from pre-conception and continued throughout pregnancy and lactation. Pups were dissected at the end of lactation. Liver tissues were removed; snap frozen and stored at -80°C. Maternal micronutrients deficiency resulted in lower (p<0.05) levels of pup liver docosahexaenoic acid (DHA) and arachidonic acid (ARA) as compared to the control group. Pup liver PPAR? and PPAR? expression was lower (p<0.05) in the BD group although there were no differences in the expression of SREBP-1c, LXR? and RXR? expression. Omega-3 fatty acids supplementation to this group normalized (p<0.05) levels of both PPAR? and PPAR? but reduced (p<0.05) SREBP-1c, LXR? and RXR? expression. There was no change in any of the transcription factors in the pup liver in the FD group. Omega-3 fatty acids supplementation to this group reduced (p<0.05) PPAR?, SREBP-1c and RXR? expression. Pup liver global methylation levels were higher (p<0.01) in both the micronutrients deficient groups and could be normalized (p<0.05) by omega-3 fatty acid supplementation. Our novel findings suggest a role for omega-3 fatty acids in the one carbon cycle in influencing the hepatic expression of transcription factors in the offspring. PMID:24587285

Meher, Akshaya; Joshi, Asmita; Joshi, Sadhana

2014-01-01

276

Differential Regulation of Hepatic Transcription Factors in the Wistar Rat Offspring Born to Dams Fed Folic Acid, Vitamin B12 Deficient Diets and Supplemented with Omega-3 Fatty Acids  

PubMed Central

Nutritional status of the mother is known to influence various metabolic adaptations required for optimal fetal development. These may be mediated by transcription factors like peroxisome proliferator activated receptors (PPARs), which are activated by long chain polyunsaturated fatty acids. The objective of the current study was to examine the expression of different hepatic transcription factors and the levels of global methylation in the liver of the offspring born to dams fed micronutrient deficient (folic acid and vitamin B12) diets and supplemented with omega-3 fatty acids. Female rats were divided into five groups (n?=?8/group) as follows; control, folic acid deficient (FD), vitamin B12 deficient (BD) and omega-3 fatty acid supplemented groups (FDO and BDO). Diets were given starting from pre-conception and continued throughout pregnancy and lactation. Pups were dissected at the end of lactation. Liver tissues were removed; snap frozen and stored at ?80°C. Maternal micronutrients deficiency resulted in lower (p<0.05) levels of pup liver docosahexaenoic acid (DHA) and arachidonic acid (ARA) as compared to the control group. Pup liver PPAR? and PPAR? expression was lower (p<0.05) in the BD group although there were no differences in the expression of SREBP-1c, LXR? and RXR? expression. Omega-3 fatty acids supplementation to this group normalized (p<0.05) levels of both PPAR? and PPAR? but reduced (p<0.05) SREBP-1c, LXR? and RXR? expression. There was no change in any of the transcription factors in the pup liver in the FD group. Omega-3 fatty acids supplementation to this group reduced (p<0.05) PPAR?, SREBP-1c and RXR? expression. Pup liver global methylation levels were higher (p<0.01) in both the micronutrients deficient groups and could be normalized (p<0.05) by omega-3 fatty acid supplementation. Our novel findings suggest a role for omega-3 fatty acids in the one carbon cycle in influencing the hepatic expression of transcription factors in the offspring. PMID:24587285

Meher, Akshaya; Joshi, Asmita; Joshi, Sadhana

2014-01-01

277

Nitric oxide negatively regulates AKT1-mediated potassium uptake through modulating vitamin B6 homeostasis in Arabidopsis.  

PubMed

Nitric oxide (NO), an active signaling molecule in plants, is involved in numerous physiological processes and adaptive responses to environmental stresses. Under high-salt conditions, plants accumulate NO quickly, and reorganize Na(+) and K(+) contents. However, the molecular connection between NO and ion homeostasis is largely unknown. Here, we report that NO lowers K(+) channel AKT1-mediated plant K(+) uptake by modulating vitamin B6 biosynthesis. In a screen for Arabidopsis NO-hypersensitive mutants, we isolated sno1 (sensitive to nitric oxide 1), which is allelic to the previously noted mutant sos4 (salt overly sensitive 4) that has impaired Na(+) and K(+) contents and overproduces pyridoxal 5'-phosphate (PLP), an active form of vitamin B6. We showed that NO increased PLP and decreased K(+) levels in plant. NO induced SNO1 gene expression and enzyme activity, indicating that NO-triggered PLP accumulation mainly occurs through SNO1-mediated vitamin B6 salvage biosynthetic pathway. Furthermore, we demonstrated that PLP significantly repressed the activity of K(+) channel AKT1 in the Xenopus oocyte system and Arabidopsis root protoplasts. Together, our results suggest that NO decreases K(+) absorption by promoting the synthesis of vitamin B6 PLP, which further represses the activity of K(+) channel AKT1 in Arabidopsis. These findings reveal a previously unidentified pivotal role of NO in modulating the homeostasis of vitamin B6 and potassium nutrition in plants, and shed light on the mechanism of NO in plant acclimation to environmental changes. PMID:25355908

Xia, Jinchan; Kong, Dongdong; Xue, Shaowu; Tian, Wang; Li, Nan; Bao, Fang; Hu, Yong; Du, Jing; Wang, Yu; Pan, Xiaojun; Wang, Lei; Zhang, Xiaochen; Niu, Guoqi; Feng, Xue; Li, Legong; He, Yikun

2014-11-11

278

Uptake of (/sup 3/H)vitamin D/sub 3/ from low and high density lipoproteins by cultured human fibroblasts  

SciTech Connect

The plasma distribution and cellular uptake of (/sup 3/H)vitamin D/sub 3/ was studied in vitro using cultured human fibroblasts. Incubation of (/sup 3/H)vitamin D/sub 3/ (cholecalciferol) with plasma followed by sequential ultracentrifugal fractionation of the lipoproteins indicated that 2-4% of the radioactivity associated with the very low density lipoprotein (VLDL), 12% with low density lipoprotein (LDL), and approximately 60% with the high density lipoprotein (HDL). The remaining radioactivity, 25%, was associated with the sedimented plasma fractions. By comparison, an average of 86% of the radioactivity from (/sup 3/H) 1,25-dihydroxycholecalciferol associated with the sedimented plasma fractions. The uptake of (/sup 3/H)vitamin D/sub 3/ from plasma, LDL, or HDL was studied in cultured human cells; uptake by normal fibroblasts was greatest from LDL and least from plasma. The cellular association of vitamin D/sub 3/ was time, concentration, and temperature dependent. At a concentration of 50 ..mu..g LDL/ml of medium, the uptake of (/sup 3/H)vitamin D/sub 3/ from LDL at 37/sup 0/C was rapid and reached a maximum at approximately 4 hr; it was slower from HDL but continued to increase slowly up to 24 hr. The significance of these in vitro findings is uncertain since much of the vitamin D/sub 3/ absorbed from the intestine reportedly associates with chylomicrons and is rapidly taken up by the liver.

Shireman, R.B.; Williams, D.; Remsen, J.F.

1986-03-01

279

Vitamin B12 and Folate Test  

MedlinePLUS

... by insufficient dietary intake, inadequate absorption, or by increased need as seen in pregnancies. Insufficient intake is uncommon in the United States because many foods and drinks are supplemented with ...

280

Vitamin B12 als biologisch aktive Modellsubstanz  

NASA Astrophysics Data System (ADS)

A critical review on corrinoid biochemistry and physiology is presented. This includes: chemical synthesis of biologically important organocorrinoids and the correlation between their structures and coenzymatic activity; forms, distribution and transport of physiologically active corrinoids; methylcobalamin- and adenosylcobalamin-dependent enzymatic reactions and their physiological functions; and steric course of the adenosylcobalamin-dependent enzymatic rearrangements. Special attention is paid to the mechanisms of adenosylcobalamin-dependent enzymatic reactions.

Zagalak, Boles?aw

1982-02-01

281

1,25(OH)2Vitamin D inhibits foam cell formation and suppresses macrophage cholesterol uptake in patients with type 2 diabetes  

PubMed Central

Background Cardiovascular disease is the leading cause of death among diabetics. Vitamin D deficiency is associated with increased risk of cardiovascular disease in this population. To determine the mechanism by which vitamin D deficiency mediates accelerated cardiovascular disease in patients with diabetes, we investigated the effects of active vitamin D on macrophage cholesterol deposition. Methods and Results We obtained macrophages from 76 obese, diabetic, hypertensive patients with vitamin D deficiency (25-hydroxyvitamin D < 80 nmol/L)(group A) and four control groups: obese, diabetic, hypertensive patients with normal vitamin D (group B, n=15), obese, non-diabetic, hypertensive patients with vitamin D deficiency (group C, n=25), and non-obese, non-diabetic, non-hypertensive patients with vitamin D deficiency (group D, n=10) or sufficiency (group E, n=10). The same patient’s macrophages from all groups were cultured in vitamin D-deficient or 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) supplemented media and exposed to modified low-density lipoprotein cholesterol. 1,25(OH)2D3 suppressed foam cell formation by reducing acetylated or oxidized low-density lipoprotein cholesterol uptake in diabetics only. Conversely, deletion of the vitamin D receptor in macrophages from diabetic patients accelerated foam-cell formation induced by modified LDL. 1,25(OH)2D3 downregulation of c-Jun N-terminal kinase activation reduced PPAR? expression, suppressed CD36 expression, and prevented oxLDL-derived cholesterol uptake. In addition, 1,25(OH)2D3 suppression of macrophage endoplasmic reticulum stress improved insulin signaling, downregulated SR-A1expression, and prevented oxLDL and AcLDL-derived cholesterol uptake. Conclusion These results identify reduced vitamin D receptor signaling as a potential mechanism underlying increased foam-cell formation and accelerated cardiovascular disease in diabetics. PMID:19667238

Oh, Jisu; Weng, Sherry; Felton, Shaili K.; Bhandare, Sweety; Riek, Amy; Butler, Boyd; Proctor, Brandon M.; Petty, Marvin; Chen, Zhouji; Schechtman, Kenneth B.; Bernal-Mizrachi, Leon; Bernal-Mizrachi, Carlos

2011-01-01

282

Relationship of membrane-bound sulfhydryl groups to vitamin D-stimulated uptake of ( sup 75 Se)Selenite by the brush border membrane vesicles from chick duodenum  

SciTech Connect

The uptake of selenite by purified brush border membrane vesicles isolated from duodena of rachitic or vitamin D-treated chicks was studied by using radioactive selenite and a rapid filtration technique. Cholecalciferol treatment (500 IU at 72 h) significantly enhanced selenite uptake, a response that decreased when the vesicles were stored at room temperature for 2.5 h prior to the uptake measurement. Preincubation of the vesicles in 1.0 mmol/L H2O2 reduced (75Se)selenite uptake, indicating the involvement of oxidizable groups in the uptake reaction. Iodoacetic acid (IAA), a sulfhydryl-blocking reagent, at 1-2 mmol/L concentration eliminated the difference in selenite uptake due to cholecalciferol and had no effect on vesicles from rachitic animals. A higher concentration of IAA (10 mmol/L) enhanced selenite uptake manyfold and increased the absolute difference due to cholecalciferol treatment. Single intravenous doses of 100 IU cholecalciferol, 100 IU ergocalciferol, or 0.1 micrograms 1,25-dihydroxycholecalciferol also stimulated selenite uptake, suggesting a general response to vitamin D compounds. Normal animals given a single dose of 1,25-dihydroxycholecalciferol 12 h prior to killing also responded. Treatments that enhanced the uptake of (75Se)selenite also increased the amount of membrane-bound sulfhydryl groups, suggesting the involvement of membrane-bound sulfhydryl groups in the vitamin D response. A significant increase in selenite uptake by intravenous 1,25-dihydroxycholecalciferol occurred within 10 min. This rapid effect provides a new tool to probe early biochemical effects of vitamin D on intestinal epithelium.

Mykkanen, H.M.; Wasserman, R.H. (Cornell Univ., Ithaca, NY (USA))

1990-08-01

283

A relationship between vitamin B sub 12 , folic acid, ascorbic acid, and mercury uptake and methylation  

SciTech Connect

Ingestion of megadoses of certain vitamins appears to influence the in vivo methylation of mercuric chloride in guinea pigs. The addition of megadoses of vitamin B{sub 12} fed either singularly or in combination with folic acid resulted in increased methylmercury concentrations in the liver. Moreover, percent methylmercury levels were significantly increased with B{sub 12} treatment in the liver (B{sub 12} only and B{sub 12}/folic acid) and brain (B{sub 12}/vitamin C). Incorporation of high levels of folic acid into the dietary regime also increased the methylmercury concentration particularly in the liver and hair tissues. The addition of vitamin C in the diet, particularly in combination with B{sub 12} (brain) or folic acid (muscle) resulted in increased methylmercury levels in these tissues and percent methylmercury values with B{sub 12} in the muscle and brain tissue.

Zorn, N.E.; Smith, J.T. (Univ. of Tennessee, Knoxville (USA))

1990-01-01

284

Enteropathogenic Escherichia coli inhibits intestinal vitamin B1 (thiamin) uptake: studies with human-derived intestinal epithelial Caco-2 cells.  

PubMed

Infection with the gram-negative enteropathogenic Escherichia coli (EPEC), a food-borne pathogen, represents a significant risk to human health. Whereas diarrhea is a major consequence of this infection, malnutrition also occurs especially in severe and prolonged cases, which may aggravate the health status of the infected hosts. Here we examined the effect of EPEC infection on the intestinal uptake of the water-soluble vitamin B1 (thiamin) using an established human intestinal epithelial Caco-2 cell model. The results showed that infecting Caco-2 cells with wild-type EPEC (but not with nonpathogenic E. coli, killed EPEC, or filtered supernatant) leads to a significant (P < 0.01) inhibition in thiamin uptake. Kinetic parameters of both the nanomolar (mediated by THTR-2) and the micromolar (mediated by THTR-1) saturable thiamin uptake processes were affected by EPEC infection. Cell surface expression of hTHTR-1 and -2 proteins, (determined by the biotinylation method) showed a significantly (P < 0.01) lower expression in EPEC-treated cells compared with controls. EPEC infection also affected the steady-state mRNA levels as well as promoter activity of the SLC19A2 and SLC19A3 genes. Infecting Caco-2 cells with EPEC mutants that harbor mutations in the escN gene (which encodes a putative ATPase for the EPEC type III secretion system, TTSS) or the espA, espB, or espD genes (which encode structural components of the TTSS) did not affect thiamin uptake. On the other hand, mutations in espF and espH genes (which encode effector proteins) exhibited partial inhibition in thiamin uptake. These results demonstrate for the first time that EPEC infection of human intestinal epithelial cells leads to inhibition in thiamin uptake via effects on physiological and molecular parameters of hTHTR-1 and -2. Furthermore, the inhibition appears to be dependent on a functional TTSS of EPEC. PMID:19628653

Ashokkumar, Balasubramaniem; Kumar, Jeyan S; Hecht, Gail A; Said, Hamid M

2009-10-01

285

RBP4 Disrupts Vitamin A Uptake Homeostasis in a STRA6-Deficient Animal Model for Matthew-Wood Syndrome  

PubMed Central

SUMMARY The cellular uptake of vitamin A from its RBP4-bound circulating form (holo-RBP4) is a homeostatic process that evidently depends on the multidomain membrane protein STRA6. In humans, mutations in STRA6 are associated with Matthew-Wood syndrome, manifested by multisystem developmental malformations. Here we addressed the metabolic basis of this inherited disease. STRA6-dependent transfer of retinol from RBP4 into cultured NIH 3T3 fibroblasts was enhanced by lecithin:retinol acyltransferase (LRAT). The retinol transfer was bidirectional, strongly suggesting that STRA6 acts as a retinol channel/transporter. Loss-of-function analysis in zebrafish embryos revealed that Stra6 deficiency caused vitamin A deprivation of the developing eyes. We provide evidence that, in the absence of Stra6, holo-Rbp4 provokes nonspecific vitamin A excess in several embryonic tissues, impairing retinoic acid receptor signaling and gene regulation. These fatal consequences of Stra6 deficiency, including craniofacial and cardiac defects and microphthalmia, were largely alleviated by reducing embryonic Rbp4 levels by morpholino oligonucleotide or pharmacological treatments. PMID:18316031

Isken, Andrea; Golczak, Marcin; Oberhauser, Vitus; Hunzelmann, Silke; Driever, Wolfgang; Imanishi, Yoshikazu; Palczewski, Krzysztof; von Lintig, Johannes

2008-01-01

286

Mielopatia por deficiência de vitamina B12 apresentando-se como mielite transversa  

Microsoft Academic Search

Vitamin B12 deficiency may induce neuropathy, myelopathy, dementia and optic neuropathy. The diagnosis is established by vitamin B12, homocysteine and methylmalonic acid measurements. Myelin and axon destruction in the white matter of the spinal cord are observed. The posterior column of the cervical and thoracic level is the most common involved area. The involvement of the anterior column is restricted

Luiz Felipe Rocha Vasconcellos; Rosalie Branco Corrêa; Leila Chimelli; Fernanda Nascimento; Adriane Baptista Fonseca; Janaina Nagel; Sergio Augusto Pereira Novis; Maurice Vincent

2002-01-01

287

Alternatives to vitamin B1 uptake revealed with discovery of riboswitches in multiple marine eukaryotic lineages.  

PubMed

Vitamin B1 (thiamine pyrophosphate, TPP) is essential to all life but scarce in ocean surface waters. In many bacteria and a few eukaryotic groups thiamine biosynthesis genes are controlled by metabolite-sensing mRNA-based gene regulators known as riboswitches. Using available genome sequences and transcriptomes generated from ecologically important marine phytoplankton, we identified 31 new eukaryotic riboswitches. These were found in alveolate, cryptophyte, haptophyte and rhizarian phytoplankton as well as taxa from two lineages previously known to have riboswitches (green algae and stramenopiles). The predicted secondary structures bear hallmarks of TPP-sensing riboswitches. Surprisingly, most of the identified riboswitches are affiliated with genes of unknown function, rather than characterized thiamine biosynthesis genes. Using qPCR and growth experiments involving two prasinophyte algae, we show that expression of these genes increases significantly under vitamin B1-deplete conditions relative to controls. Pathway analyses show that several algae harboring the uncharacterized genes lack one or more enzymes in the known TPP biosynthesis pathway. We demonstrate that one such alga, the major primary producer Emiliania huxleyi, grows on 4-amino-5-hydroxymethyl-2-methylpyrimidine (a thiamine precursor moiety) alone, although long thought dependent on exogenous sources of thiamine. Thus, overall, we have identified riboswitches in major eukaryotic lineages not known to undergo this form of gene regulation. In these phytoplankton groups, riboswitches are often affiliated with widespread thiamine-responsive genes with as yet uncertain roles in TPP pathways. Further, taxa with 'incomplete' TPP biosynthesis pathways do not necessarily require exogenous vitamin B1, making vitamin control of phytoplankton blooms more complex than the current paradigm suggests. PMID:25171333

McRose, Darcy; Guo, Jian; Monier, Adam; Sudek, Sebastian; Wilken, Susanne; Yan, Shuangchun; Mock, Thomas; Archibald, John M; Begley, Tadhg P; Reyes-Prieto, Adrian; Worden, Alexandra Z

2014-12-01

288

Uptake of technetium-99m methylene diphosphonate by fractured and osteoporotic bone after a pulse dose of Vitamin D/sub 3/. [Rats  

SciTech Connect

The effect of a pulse dose of Vitamin D/sub 3/ on uptake of (/sup 99m/Tc)MDP by fractured and osteoporotic bone, respectively, was compared with D/sub 3/'s effect on uptake by normal bone in rats. At 4, 7, and 14 days, respectively, after femoral fracture, basal uptake was significantly increased at the fracture site by 336.8, 276.1, and 183.5%, respectively, over the contralateral control site. D/sub 3/-treated rats had lower uptakes than untreated controls at all three fracture sites and at 12 of 15 normal bone sites but analysis of variance showed the uptake differences were not significant. Cortisone-induced osteoporosis caused a significant decrease in basal uptake. The decrease occurred in all nine bone areas studied. D/sub 3/ caused a significant increase in uptake by these osteoporotic bones, but a significant decrease in uptake by the same bones in normal controls. Thus, D/sub 3/ had an effect on uptake by the bone lesion, osteoporosis, that differed from D/sub 3/'s effect on uptake by fracture or normal bone.

Carr, E.A. Jr.; Carroll, M.; Montes, M.; Zielezny, M.

1985-04-01

289

Food protein-based microspheres for increased uptake of vitamin D3.  

PubMed

To protect vitamin D3 during cold storage and exposure to UV-light, vitamin D3 has been entrapped in microspheres formed by bovine protein ?-lactoglobulin (?lg) and lysozyme (Lyso) from egg white. The behaviour of the ?lg/Lyso microspheres in simulated intestinal fluid and their impact on the kinetic release of D3 were determined. The impact of the D3-loaded ?lg/Lyso microspheres on the bioavailability of D3 was evaluated in vivo by force-feeding rats. The data indicate that the ?lg/Lyso microspheres effectively improved the stability of D3, which was readily released in the intestines. The release kinetics were accelerated in the presence of proteolytic enzymes. The bioavailability of D3 was improved, as confirmed by the significant increase in the serum levels of 25-hydroxy-D3 in rats. The current work demonstrates that water soluble proteins were used to substantially increase the bioavailability of the lipophilic vitamin, and thus can serve in the oral delivery of D3. PMID:25466126

Diarrassouba, Fatoumata; Garrait, Ghislain; Remondetto, Gabriel; Alvarez, Pedro; Beyssac, Eric; Subirade, Muriel

2015-04-15

290

Vitamin B1 (thiamine) uptake by human retinal pigment epithelial (ARPE-19) cells: mechanism and regulation.  

PubMed

Retinal abnormality and visual disturbances occur in thiamine-responsive megaloblastic anaemia (TRMA), an autosomal recessive disorder caused by mutations in the human thiamine transporter-1 (hTHTR-1). Human retinal pigment epithelial cells play a pivotal role in supplying thiamine to the highly metabolically active retina but nothing is known about the mechanism, regulation or biological processes involved in thiamine transport in these cells. To address these issues, we used human-derived retinal pigment epithelial ARPE-19 cells to characterize the thiamine uptake process. Thiamine uptake is energy- and temperature-dependent, pH-sensitive, Na+-independent, saturable at both the nanomolar (apparent Km, 30 +/- 5 nM) and the micromolar (apparent Km, 1.72 +/- 0.3 microM) concentration ranges, specific for thiamine and sensitive to sulfhydryl group inhibition. The diuretic amiloride caused a concentration-dependent inhibition in thiamine uptake, whereas the anti-trypanosomal drug, melarsoprol, failed to affect the uptake process. Both hTHTR-1 and hTHTR-2 are expressed in ARPE-19 cells as well as in native human retinal tissue with expression of the former being significantly higher than that of the latter. Uptake of thiamine was adaptively regulated by extracellular substrate level via transcriptionally mediated mechanisms that involve both hTHTR-1 and hTHTR-2; it was also regulated by an intracellular Ca2+-calmodulin-mediated pathway. Confocal imaging of living ARPE-19 cells expressing TRMA-associated hTHTR-1 mutants (D93H, S143F and G172D) showed various expression phenotypes. These results demonstrate for the first time the existence of a specialized and regulated uptake process for thiamine in a cellular model of human retinal pigment epithelia that involves hTHTR-1 and hTHTR-2. Further, clinically relevant mutations in hTHTR-1 lead to impaired cell surface expression or function of the transporter in retinal epithelial ARPE-19 cells. PMID:17463047

Subramanian, Veedamali S; Mohammed, Zainab M; Molina, Andres; Marchant, Jonathan S; Vaziri, Nosratola D; Said, Hamid M

2007-07-01

291

Nuclear lipid microdomains regulate nuclear vitamin D3 uptake and influence embryonic hippocampal cell differentiation  

PubMed Central

Despite recent advances in the understanding of the role of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) in the CNS, the mechanism of action remains obscure. We demonstrate that some 1,25-(OH)2D3 receptor (VDR) is localized in the cell nucleus in specialized microdomains enriched in sphingomyelin and cholesterol; the integrity of these microdomains is necessary for embryonic hippocampal cell differentiation. Sphingomyelinase (SMase) treatment reduces both VDR and labeled 1,25-(OH)2D3 content in nuclear microdomains. We have previously shown that HN9.10e embryonic hippocampal cells differentiate when incubated with 100 nM 1,25-(OH)2D3 in the presence of 10% fetal calf serum, while serum deprivation induces cell death. In this study, we have investigated whether conditions that alter lipid content of nuclear microdomains modify 1,25-(OH)2D3–induced differentiation. Serum deprivation activates SMase and modifies the composition of nuclear microdomains, which lose the 1,25-(OH)2 vitamin D3 receptor. The incubation of serum-deprived cells with 100 nM 1,25-(OH)2D3 prevents differentiation. However, treatment with 400 nM 1,25-(OH)2D3 during serum withdrawal increases the lipid content of the nuclear microdomains, allows the interaction of 1,25-(OH)2D3 with its receptor, and results in differentiation. These results suggest the presence of VDR in nuclear microdomains is necessary for 1,25-(OH)2D3–induced differentiation in embryonic hippocampal cells. PMID:21737687

Bartoccini, Elisa; Marini, Francesca; Damaskopoulou, Eleni; Lazzarini, Remo; Cataldi, Samuela; Cascianelli, Giacomo; Gil Garcia, Mercedes; Albi, Elisabetta

2011-01-01

292

Pyridoxine (Vitamin B6)  

MedlinePLUS

... for Alzheimer's disease, attention deficit-hyperactivity disorder (ADHD), Down syndrome, autism, diabetes and related nerve pain, sickle cell ... acid and vitamin B12.Preventing re-blockage of blood vessels after angioplasty. Boosting the immune system. Muscle cramps. ...

293

Crystallographic studies on B12 binding proteins in eukaryotes and prokaryotes  

PubMed Central

The x-ray crystal structures of several important vitamin B12 binding proteins that have been solved in recent years have enhanced our current understanding in the vitamin B12 field. These structurally diverse groups of B12 binding proteins perform various important biological activities, both by transporting B12 as well as catalyzing various biological reactions. An in-depth comparative analysis of these structures was carried out using PDB coordinates of a carefully chosen database of B12 binding proteins to correlate the overall folding of the molecule with phylogeny, the B12 interactions, and with their biological function. The structures of these proteins are discussed in the context of this comparative analysis. PMID:23395752

Sukumar, Narayanasami

2013-01-01

294

Vitamin-responsive disorders: cobalamin, folate, biotin, vitamins B1 and E.  

PubMed

The catalytic properties of many enzymes depend on the participation of vitamins as obligatory cofactors. Vitamin B12 (cobalamin) and folic acid (folate) deficiencies in infants and children classically present with megaloblastic anemia and are often accompanied by neurological signs. A number of rare inborn errors of cobalamin and folate absorption, transport, cellular uptake, and intracellular metabolism have been delineated and identification of disease-causing mutations has improved our ability to diagnose and treat many of these conditions. Two inherited defects in biotin metabolism are known, holocarboxylase synthetase and biotinidase deficiency. Both lead to multiple carboxylase deficiency manifesting with metabolic acidosis, neurological abnormalities, and skin rash. Thiamine-responsive megaloblastic anemia is characterized by megaloblastic anemia, non-type I diabetes, and sensorineural deafness that responds to pharmacological doses of thiamine (vitamin B1). Individuals affected with inherited vitamin E deficiencies including ataxia with isolated vitamin E deficiency and abetalipoproteinemia present with a spinocerebellar syndrome similar to patients with Friedreich's ataxia. If started early, treatment of these defects by oral or parenteral administration of the relevant vitamin often results in correction of the metabolic defect and reversal of the signs of disease, stressing the importance of early and correct diagnosis in these treatable conditions. PMID:23622402

Baumgartner, Matthias R

2013-01-01

295

An Endocytic Pathway Essential for Renal Uptake and Activation of the Steroid 25-(OH) Vitamin D 3  

Microsoft Academic Search

Steroid hormones may enter cells by diffusion through the plasma membrane. However, we demonstrate here that some steroid hormones are taken up by receptor-mediated endocytosis of steroid-carrier complexes. We show that 25-(OH) vitamin D3 in complex with its plasma carrier, the vitamin D–binding protein, is filtered through the glomerulus and reabsorbed in the proximal tubules by the endocytic receptor megalin.

Anders Nykjaer; Duska Dragun; Diego Walther; Henrik Vorum; Christian Jacobsen; Joachim Herz; Flemming Melsen; Erik Ilsoe Christensen; Thomas E Willnow

1999-01-01

296

The Vitamin D Receptor (VDR) Is Expressed in Skeletal Muscle of Male Mice and Modulates 25-Hydroxyvitamin D (25OHD) Uptake in Myofibers  

PubMed Central

Vitamin D deficiency is associated with a range of muscle disorders, including myalgia, muscle weakness, and falls. In humans, polymorphisms of the vitamin D receptor (VDR) gene are associated with variations in muscle strength, and in mice, genetic ablation of VDR results in muscle fiber atrophy and motor deficits. However, mechanisms by which VDR regulates muscle function and morphology remain unclear. A crucial question is whether VDR is expressed in skeletal muscle and directly alters muscle physiology. Using PCR, Western blotting, and immunohistochemistry (VDR-D6 antibody), we detected VDR in murine quadriceps muscle. Detection by Western blotting was dependent on the use of hyperosmolar lysis buffer. Levels of VDR in muscle were low compared with duodenum and dropped progressively with age. Two in vitro models, C2C12 and primary myotubes, displayed dose- and time-dependent increases in expression of both VDR and its target gene CYP24A1 after 1,25(OH)2D (1,25 dihydroxyvitamin D) treatment. Primary myotubes also expressed functional CYP27B1 as demonstrated by luciferase reporter studies, supporting an autoregulatory vitamin D-endocrine system in muscle. Myofibers isolated from mice retained tritiated 25-hydroxyvitamin D3, and this increased after 3 hours of pretreatment with 1,25(OH)2D (0.1nM). No such response was seen in myofibers from VDR knockout mice. In summary, VDR is expressed in skeletal muscle, and vitamin D regulates gene expression and modulates ligand-dependent uptake of 25-hydroxyvitamin D3 in primary myofibers. PMID:24949660

Mokbel, Nancy; Cha, Kuan Minn; Houweling, Peter J.; Abboud, Myriam; Fraser, David R.; Mason, Rebecca S.; Clifton-Bligh, Roderick J.

2014-01-01

297

Multiple B-vitamin depletion in large areas of the coastal ocean  

PubMed Central

B vitamins are some of the most commonly required biochemical cofactors in living systems. Therefore, cellular metabolism of marine vitamin-requiring (auxotrophic) phytoplankton and bacteria would likely be significantly compromised if B vitamins (thiamin B1, riboflavin B2, pyridoxine B6, biotin B7, and cobalamin B12) were unavailable. However, the factors controlling the synthesis, ambient concentrations, and uptake of these key organic compounds in the marine environment are still not well understood. Here, we report vertical distributions of five B vitamins (and the amino acid methionine) measured simultaneously along a latitudinal gradient through the contrasting oceanographic regimes of the southern California-Baja California coast in the Northeast Pacific margin. Although vitamin concentrations ranged from below the detection limits of our technique to 30 pM for B2 and B12 and to ?500 pM for B1, B6, and B7, each vitamin showed a different geographical and depth distribution. Vitamin concentrations were independent of each other and of inorganic nutrient levels, enriched primarily in the upper mesopelagic zone (depth of 100–300 m), and associated with water mass origin. Moreover, vitamin levels were below our detection limits (ranging from ?0.18 pM for B12 to ?0.81 pM for B1) in extensive areas (100s of kilometers) of the coastal ocean, and thus may exert important constraints on the taxonomic composition of phytoplankton communities, and potentially also on rates of primary production and carbon sequestration. PMID:22826241

Sañudo-Wilhelmy, Sergio A.; Cutter, Lynda S.; Durazo, Reginaldo; Smail, Emily A.; Gómez-Consarnau, Laura; Webb, Eric A.; Prokopenko, Maria G.; Berelson, William M.; Karl, David M.

2012-01-01

298

Coenzyme B12 can be produced by engineered Escherichia coli under both anaerobic and aerobic conditions.  

PubMed

Coenzyme B12 (Vitamin B12 ) is one of the most complex biomolecules and an essential cofactor required for the catalytic activity of many enzymes. Pseudomonas denitrificans synthesizes coenzyme B12 in an oxygen-dependent manner using a pathway encoded by more than 25 genes that are located in six different operons. Escherichia coli, a robust and suitable host for metabolic engineering was used to produce coenzyme B12 . These genes were cloned into three compatible plasmids and expressed heterologously in E. coli BL21 (DE3). Real-time PCR, SDS-PAGE analysis and bioassay showed that the recombinant E. coli expressed the coenzyme B12 synthetic genes and successfully produced coenzyme B12 . However, according to the quantitative determination by inductively coupled plasma-mass spectrometry, the amount of coenzyme B12 produced by the recombinant E. coli (0.21 ± 0.02 ?g/g cdw) was approximately 13-fold lower than that by P. denitrificans (2.75 ± 0.22 ?g/g cdw). Optimization of the culture conditions to improve the production of coenzyme B12 by the recombinant E. coli was successful, and the highest titer (0.65 ± 0.03 ?g/g cdw) of coenzyme B12 was obtained. Interestingly, although the synthesis of coenzyme B12 in P. denitrificans is strictly oxygen-dependent, the recombinant E. coli could produce coenzyme B12 under anaerobic conditions. PMID:25146562

Ko, Yeounjoo; Ashok, Somasundar; Ainala, Satish Kumar; Sankaranarayanan, Mugesh; Chun, Ah Yeong; Jung, Gyoo Yeol; Park, Sunghoon

2014-12-01

299

Differentiation-dependent regulation of intestinal vitamin B(2) uptake: studies utilizing human-derived intestinal epithelial Caco-2 cells and native rat intestine.  

PubMed

Intestinal epithelial cells undergo differentiation as they move from the crypt to the villi, a process that is associated with up- and downregulation in expression of a variety of genes, including those involved in nutrient absorption. Whether the intestinal uptake process of vitamin B(2) [riboflavin (RF)] also undergoes differentiation-dependent regulation and the mechanism through which this occurs are not known. We used human-derived intestinal epithelial Caco-2 cells and native rat intestine as models to address these issues. Caco-2 cells showed a significantly higher carrier-mediated RF uptake in post- than preconfluent cells. This upregulation was associated with a significantly higher level of protein and mRNA expression of the RF transporters hRFVT-1 and hRFVT-3 in the post- than preconfluent cells; it was also accompanied with a significantly higher rate of transcription of the respective genes (SLC52A1 and SLC52A3), as indicated by the higher level of expression of heterogeneous nuclear RNA and higher promoter activity in post- than preconfluent cells. Studies with native rat intestine also showed a significantly higher RF uptake by epithelial cells of the villus tip than epithelial cells of the crypt; this again was accompanied by a significantly higher level of expression of the rat RFVT-1 and RFVT-3 at the protein, mRNA, and heterogeneous nuclear RNA levels. These findings show, for the first time, that the intestinal RF uptake process undergoes differentiation-dependent upregulation and suggest that this is mediated (at least in part) via transcriptional mechanisms. PMID:23413253

Subramanian, Veedamali S; Ghosal, Abhisek; Subramanya, Sandeep B; Lytle, Christian; Said, Hamid M

2013-04-15

300

Skin and mucosal manifestations in vitamin deficiency.  

PubMed

The skin and mucosal changes in vitamin deficiency are described. Pellagra, which is the oldest known cutaneous manifestation among vitamin deficiencies, is reviewed. Cutaneous alterations caused by deficiency of the water-soluble vitamins B6, C, B1 and biotin, B12, folic acid, and riboflavin result in more mucosal alterations and are discussed. Alterations caused by fat-soluble vitamin deficiencies (vitamins A and K) are also considered. PMID:2948974

Barthelemy, H; Chouvet, B; Cambazard, F

1986-12-01

301

Mammalian colonocytes possess a carrier-mediated mechanism for uptake of vitamin B3 (niacin): studies utilizing human and mouse colonic preparations  

PubMed Central

Niacin (vitamin B3; nicotinic acid) plays an important role in maintaining redox state of cells and is obtained from endogenous and exogenous sources. The latter source has generally been assumed to be the dietary niacin, but another exogenous source that has been ignored is the niacin that is produced by the normal microflora of the large intestine. For this source of niacin to be bioavailable, it needs to be absorbed, but little is known about the ability of the large intestine to absorb niacin and the mechanism involved. Here we addressed these issues using the nontransformed human colonic epithelial NCM460 cells, native human colonic apical membrane vesicles (AMV) isolated from organ donors, and mouse colonic loops in vivo as models. Uptake of 3H-nicotinic acid by NCM460 cells was: 1) acidic pH (but not Na+) dependent; 2) saturable (apparent Km = 2.5 ± 0.8 ?M); 3) inhibited by unlabeled nicotinic acid, nicotinamide, and probenecid; 4) neither affected by other bacterially produced monocarboxylates, monocarboxylate transport inhibitor, or by substrates of the human organic anion transporter-10; 5) affected by modulators of the intracellular protein tyrosine kinase- and Ca2+-calmodulin-regulatory pathways; and 6) adaptively regulated by extracellular nicotinate level. Uptake of nicotinic acid by human colonic AMV in vitro and by mouse colonic loops in vivo was also carrier mediated. These findings report, for the first time, that mammalian colonocytes possess a high-affinity carrier-mediated mechanism for nicotinate uptake and show that the process is affected by intracellular and extracellular factors. PMID:23744738

Kumar, Jeyan S.; Subramanian, Veedamali S.; Kapadia, Rubina; Kashyap, Moti L.

2013-01-01

302

Gut Microbes Take Their Vitamins  

PubMed Central

The dense microbial ecosystem within the gut is connected through a complex web of metabolic interactions. In this issue of Cell Host & Microbe, Degnan et al. (2014) establish the importance of different vitamin B12transporters that help a Bacteroides species acquire vitamins from the environment tomaintain a competitive edge. PMID:24439893

Sonnenburg, Erica D.; Sonnenburg, Justin L.

2014-01-01

303

Studies in the biosynthesis of vitamin B12  

E-print Network

catalyzing the C-2 and C-7 methylations of Uroporphyrinogen III to precorrin-2, without performing an extra methylation at C-12 of precorrin-2 to trimethylpyrrocorphin. The function of the S.typhimurium cbid gene product has not yet been identified. The C...

Anousis, Nick

2012-06-07

304

Uptake and storage of vitamin A as lipid droplets in the cytoplasm of cells in the lamina propria mucosae of the rat intestine.  

PubMed

Vitamin A (retinyl palmitate) was injected subcutaneously or administered to rats by tube feeding. After subcutaneous injection, vitamin A was taken up and stored in cells of the lamina propria mucosae of the rat intestine. After oral administration, vitamin A was absorbed by the intestinal absorptive epithelial cells and transferred to cells of the lamina propria mucosae, where cells took up and stored the transferred vitamin A. The morphology of these cells was similar to that of hepatic stellate cells (also called vitamin A-storing cells, lipocytes, interstitial cells, fat-storing cells or Ito cells). Thus, these cells in the intestine could take up vitamin A from the systemic circulation and as well as by intestinal absorption, and store the vitamin in the lipid droplets in their cytoplasm. The data suggest that these cells are extrahepatic stellate cells of the digestive tract that may play roles in both the absorption and homeostasis of vitamin A. PMID:23765517

Senoo, Haruki; Mezaki, Yoshihiro; Morii, Mayako; Hebiguchi, Taku; Miura, Mitsutaka; Imai, Katsuyuki

2013-11-01

305

The association of dietary folate, B6, and B12 with cardiovascular mortality in Spain: an ecological analysis.  

PubMed Central

OBJECTIVES: This study assessed the association of dietary folate, vitamin B6, and vitamin B12 with cardiovascular mortality. METHODS: Poisson regression analyses assessed coronary/cerebrovascular mortality rates via nutrient data obtained from the National Nutrition Survey, which recorded 7-day food intakes from a national sample of 21,155 households. RESULTS: In regard to coronary mortality, male and female rate ratios (highest vs lowest quintile) were 0.83 (95% confidence interval [CI] = 0.77, 0.91) and 0.95 (95% CI = 0.86, 1.05), respectively, for folate and 0.74 (95% CI = 0.65, 0.84) and 0.86 (95% CI = 0.73, 0.99), respectively, for B12. Intake of folate and B6 (but not B12) was significantly associated with cerebrovascular mortality. CONCLUSIONS: B vitamins are associated with cardiovascular mortality in the general population. PMID:11030004

Medrano, M J; Sierra, M J; Almazán, J; Olalla, M T; López-Abente, G

2000-01-01

306

Vitamin A  

MedlinePLUS

... QuickFacts Datos en español Health Professional Other Resources Vitamin A Fact Sheet for Consumers What is vitamin A and what does it do? Vitamin A ... out more about vitamin A? Disclaimer How much vitamin A do I need? The amount of vitamin ...

307

Vitamin E  

MedlinePLUS

... Datos en español Health Professional Other Resources Vitamin E Fact Sheet for Consumers What is vitamin E and what does it do? Vitamin E is ... more about vitamin E? Disclaimer How much vitamin E do I need? The amount of vitamin E ...

308

B12Hn and B12Fn: planar vs icosahedral structures  

PubMed Central

Using density functional theory and quantum Monte Carlo calculations, we show that B12Hn and B12Fn (n = 0 to 4) quasi-planar structures are energetically more favorable than the corresponding icosahedral clusters. Moreover, we show that the fully planar B12F6 cluster is more stable than the three-dimensional counterpart. These results open up the possibility of designing larger boron-based nanostructures starting from quasi-planar or fully planar building blocks. PMID:22546348

2012-01-01

309

Prevalence of pernicious anemia in patients with macrocytic anemia and low serum B12  

PubMed Central

Objective: The current research evaluated the prevalence of pernicious anemia (PA) in patients with macrocytic anemia (high MCV) and low serum B12 in Riyadh. Methods: Blood testing was done in 77 patients (males: 45.5%, females: 54.5%) with macrocytic anemia; 84 patients; (males: 23.8%, females: 76.2%) with low serum B12 and 30 healthy subjects. Complete blood count, differential count, folic acid, vitamin B12, intrinsic factor, gastric parietal cell antibodies and holotranscobalamin II were assessed. Results: A total of five subjects from 161 patients had PA; three of these patients had macrocyticanemia (3.90%) and two patients had low serum B12 (2.38%). Significant differences (p<0.05) in some hematological, immunological, biochemical parameters were found in subjects with macrocytic anemia and low serum B12 compared to controls. Conclusions: Pernicious anemia in patients with macrocytic anemia and low serum B12 was for the selected sample size can be assumed to be uncommon in Riyadh, Saudi Arabia.

AA, Abdulmanea; AH, Alsaeed; AP, Shaik; FH, AlGahtani

2014-01-01

310

Vitamin nutrition in older adults.  

PubMed

Proper vitamin nutrition is essential for all people but especially for elderly persons, because they are at higher risk for deficiency than younger adults. A review of the clinical effects of vitamin deficiency shows how easily deficiency can masquerade as other morbidities, such as skin, neurologic, and gait abnormalities. Given the numerous readily available forms and sources of supplementation, their low cost, and their rather limited potential for harm, the goal of good vitamin nutrition for the elderly is easily attainable. To be successful in this goal, physicians must look for patients at risk and for those with features of frank vitamin deficiency. Laboratory testing is most helpful with respect to vitamin B12 and folate deficiency. Given the great value of clinical assessment, the low cost of vitamins, and the higher cost of laboratory testing, the authors do not recommend testing before instituting multivitamin use or extra supplementation with individual vitamins unless the diagnosis of deficiency is in question or the use of supplementation would put the patient at risk. The authors' general recommendations are * one multivitamin daily * extra vitamin E for patients with cardiovascular risk factors or Alzheimer's dementia * extra vitamin D for patients with known osteoporosis, osteoporosis risk factors, or strong risk factors for vitamin D deficiency * extra folate for patients with cardiovascular risk factors (especially smokers) and alcoholics * extra thiamine for alcoholics. PMID:12608503

Johnson, Karin A; Bernard, Marie A; Funderburg, Karen

2002-11-01

311

Vitamin D  

MedlinePLUS

... News Anxiety Disorders Relaxation Exercises The Flu Vaccine Vitamin D KidsHealth > Teens > Food & Fitness > Nutrition Basics > Vitamin ... get the recommended daily amount. Continue How Much Vitamin D Do I Need? The Institute of Medicine ( ...

312

B12 STORAGE DISEASE; COBALAMIN F DISEASE; cblF; METHYLMALONICACIDURIA DUE TO VITAMIN B12-RELEASE DEFECT)  

E-print Network

acidemia and homocystinemia, ” Genet Med. 1999 May-Jun;1(4):146-50. 2. Andersson H, Shapria E. “Biochemical and clinical response to hydroxycobalamin versus cyanocobalamin treatment in patients with methylmalonic acidemia and homocystinuria (cblC), ” J Pediatr 1998; 132(1): 121-124. 3. Augoustides-Savvopoulou P, Mylonas I, Sewell AC, Rosenbaltt DS. “Reversible dementia in adolescent with cblC disease: Clinical heterogeneity within the same family, ” J Inher Metab Dis 1999; 22: 756- 758. 4. Baumgartner ER, Fowler B, Wendel U. “Hereditary defect of cobalamin metabolism (homocystinuria and methylmalonic aciduria) of juvenile onset, ” J Neurol Neurosurg Psychiatry 1996; 60(1): 107-108.

Type Methylmalonicacidemia; Homocystinuria Cbld Vitamin B; Andersson Hc; Marble M; Brunelli Sm; Meyers Ke; Guttenberg M; Kaplan P; Kaplan Bs. “co

313

Letter: Oral contraceptives and vitamin requirements.  

PubMed

Most women who use oral contraceptives should take daily vitamin supplements in dosages that are carefully regulated to avoid excesses of particular vitamins. Requirements for riboflavin, thiamine, B12, and B6 may be increased by the use of oral contraceptives, whereas niacin requirements may be reduced. Fat-soluble vitamins are also influenced by oral contraceptives. There is evidence of increases in plasma Vitamin-A and decreases in plasma tocopherols in users of oral contraceptives; Vitamin-D, Vitamin-K, and biotin, however, have not been shown to be affected. Normalization of vitamin status can be effected fairly quickly by use of a daily multivitamin. Desirable doses are as follows: ascorbic acid, 400-500 mg; ribovlavin, 10 mg; B6, 5 mg; B12, 4 mcg; and d-alpha-tocopherol, 10 mg; optimal thiamine intake is not known . Clinical signs of hypovitaminosis include depression, susceptibility to infections, and skin signs, all of which were found in users of oral contraceptives in an epidemiological survey of 46,000 women in Great Britain. Adverse psychological, dermatological, and hematological side effects of oral contraceptives have also responded to vitamin therapy. Routine prophylactic prescription of carefully formulated supplemental vitamin mixtures is recommended. PMID:1143135

Briggs, M; Briggs, M

1975-03-22

314

Urinary water-soluble vitamins and their metabolite contents as nutritional markers for evaluating vitamin intakes in young Japanese women.  

PubMed

Little information is available to estimate water-soluble vitamin intakes from urinary vitamins and their metabolite contents as possible nutritional markers. Determination of the relationships between the oral dose and urinary excretion of water-soluble vitamins in human subjects contributes to finding valid nutrition markers of water-soluble vitamin intakes. Six female Japanese college students were given a standard Japanese diet in the first week, the same diet with a synthesized water-soluble vitamin mixture as a diet with approximately onefold vitamin mixture based on Dietary Reference Intakes (DRIs) for Japanese in the second week, with a threefold vitamin mixture in the third week, and a sixfold mixture in the fourth week. Water-soluble vitamins and their metabolites were measured in the 24-h urine collected each week. All urinary vitamins and their metabolite levels except vitamin B(12) increased linearly in a dose-dependent manner, and highly correlated with vitamin intake (r=0.959 for vitamin B(1), r=0.927 for vitamin B(2), r=0.965 for vitamin B(6), r=0.957 for niacin, r=0.934 for pantothenic acid, r=0.907 for folic acid, r=0.962 for biotin, and r=0.952 for vitamin C). These results suggest that measuring urinary water-soluble vitamins and their metabolite levels can be used as good nutritional markers for assessing vitamin intakes. PMID:18635909

Fukuwatari, Tsutomu; Shibata, Katsumi

2008-06-01

315

Diet and Asthma: Vitamins and Methyl Donors  

PubMed Central

SUMMARY Dietary changes may partly explain the high burden of asthma in industrialized nations. Experimental studies have motivated a significant number of observational studies of the relation between vitamins (A, C, D, and E) or nutrients acting as methyl donors (folate, vitamin B12, and choline) and asthma. Because observational studies are susceptible to several sources of bias, well-conducted randomized controlled trials (RCTs) remain the “gold standard” to determine whether a vitamin or nutrient has an effect on asthma. Evidence from observational studies and/or relatively few RCTs most strongly justify ongoing and future RCTs of: 1) vitamin D to prevent or treat asthma, 2) choline supplementation as adjuvant treatment for asthma, and 3) vitamin E to prevent the detrimental effects of air pollution in subjects with asthma. At this time, there is insufficient evidence to recommend supplementation with any vitamin or nutrient acting as a methyl donor to prevent or treat asthma. PMID:24461761

Han, Yueh-Ying; Blatter, Josh; Brehm, John M.; Forno, Erick; Litonjua, Augusto A; Celedón, Juan C.

2014-01-01

316

32 CFR 806b.12 - Requesting the Social Security Number.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Requesting the Social Security Number. 806b.12 Section...Information § 806b.12 Requesting the Social Security Number. When asking an individual for his or her Social Security Number, always give a...

2011-07-01

317

32 CFR 806b.12 - Requesting the Social Security Number.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Requesting the Social Security Number. 806b.12 Section...Information § 806b.12 Requesting the Social Security Number. When asking an individual for his or her Social Security Number, always give a...

2010-07-01

318

Ferrocene analogues of sandwich B12·Cr·B12: a theoretical study.  

PubMed

The bowl B(12) cluster was previously reported to be analogous to benzene and predicted to be one of the best candidates to be new inorganic ligands. The structural stability and electronic properties of a new sandwich compound Cr(B(12))(2) (D(3d)) have been investigated by using density functional theory. It is found that the sandwich Cr(B(12))(2) (D(3d)) is a stable complex with large binding energy (-5.93 eV) and HOMO-LUMO gap (2.37 eV), as well as Fe(C(5)H(5))(2) and Cr(C(6)H(6))(2), following the 18-electron principle. The detailed molecular orbitals and aromaticity analyses indicate that the sandwich compound Cr(B(12))(2) (D(3d)) is electronically very stable. The natural bond orbital analysis suggests that spd-? interaction plays an important role in the sandwich compounds. PMID:23320677

Yuan, Yuan; Cheng, Longjiu

2013-01-14

319

Organometallic B12-DNA conjugate: synthesis, structure analysis, and studies of binding to human B12-transporter proteins.  

PubMed

Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in humans and animals, through the endogenous B12 transport systems. Binding of the organometallic B12 octadecanucleotide to the three important human proteins of B12 transport was studied, to examine its structural suitability for the task of eventual in vivo oligonucleotide delivery. Binding was efficient with transcobalamin (TC), but not so efficient with the homologous glycoproteins intrinsic factor and haptocorrin. Binding of the B12 octadecanucleotide to TC suggests the capacity of the B12 moiety to serve as a natural vector for specific transport of single stranded, organometallic oligonucleotide loads from the blood stream into cells. PMID:25168390

Hunger, Miriam; Mutti, Elena; Rieder, Alexander; Enders, Barbara; Nexo, Ebba; Kräutler, Bernhard

2014-10-01

320

Vitamin C  

MedlinePLUS

Vitamin C is an antioxidant. It is important for your skin, bones, and connective tissue. It promotes healing and helps the body absorb iron. Vitamin C comes from fruits and vegetables. Good sources ...

321

Vitamin K  

MedlinePLUS

Vitamin K helps your body by making proteins for healthy bones and tissues. It also makes proteins for blood clotting. If you don't have enough vitamin K, you may bleed too much. Newborns have very ...

322

Vitamin E  

MedlinePLUS

... Sickle cell disease. Taking vitamin E with aged garlic extract and vitamin C might be useful for ... people. These herbs include angelica, asafoetida, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, horse chestnut, meadowsweet, poplar, ...

323

Vitamin A  

MedlinePLUS

... carotene does not seem to prevent esophageal cancer. Pancreatic cancer. Taking vitamin A in combination with beta-carotene does not seem to prevent pancreatic cancer. Colorectal cancer. Taking vitamin A in combination with ...

324

Vitamin C  

MedlinePLUS

... C has been a popular remedy for the common cold. Research shows that for most people, vitamin C ... do not reduce the risk of getting the common cold. However, people who take vitamin C supplements regularly ...

325

Vitamin C  

MedlinePLUS

... it endorse any particular products. Search the Nutrition Source Search for: How Much Do I Need? Vitamin ... a good diet and a standard multivitamin. Food sources: Excellent food sources of vitamin C are citrus ...

326

Vitamin Analysis  

NASA Astrophysics Data System (ADS)

Vitamins are defined as relatively low-molecular-weight compounds which humans, and for that matter, any living organism that depends on organic matter as a source of nutrients, require small quantities for normal metabolism. With few exceptions, humans cannot synthesize most vitamins and therefore need to obtain them from food and supplements. Insufficient levels of vitamins result in deficiency diseases [e.g., scurvy and pellagra, which are due to the lack of ascorbic acid (vitamin C) and niacin, respectively].

Pegg, Ronald B.; Landen, W. O.; Eitenmiller, Ronald R.

327

Vitamin D  

MedlinePLUS

Vitamin D helps your body absorb calcium. Calcium is one of the main building blocks of bone. A lack of vitamin D can lead to bone diseases such as osteoporosis or rickets. Vitamin D also has a role in your nerve, ...

328

Vitamin K  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin K, a fat-soluble vitamin, is an enzyme cofactor for post-translation modification of specific glutamate residues that are converted into '-carboxyglutamic acid (Gla) residues by a vitamin K-dependent (VKD) carboxylase. Seven VKD coagulation proteins are synthesized in the liver. The extra-he...

329

Vitamin B?? and unidentified factors in poultry nutrition  

E-print Network

VITAMIN B12 AND UNIDENTIFIED FACTORS II POULTRY NUTRITION A Dissertation by Billy E. Welch Approved as to s>/I^ and content by Chairman of Committee Heafcf of Department May 1954 L I B R A R Y A & M CoLLuCiS OF TEXAS VITAMIN B12..., Pearl River, N. Y ., for supplies of folic acid; Hoffmann-La Roche Inc., Nutley, M. J., for biotin; Merck and Co., Rahway, N. J., for the rest of the B-vitamins; and Buckeye Cotton Oil Company, Cincinnati, Ohio, for soybean oil. To Lou. ?Tj! I"7 r...

Welch, Billy E.

2013-10-04

330

Fat-soluble vitamin intestinal absorption: Absorption sites in the intestine and interactions for absorption.  

PubMed

The interactions occurring at the intestinal level between the fat-soluble vitamins A, D, E and K (FSVs) are poorly documented. We first determined each FSV absorption profile along the duodenal-colonic axis of mouse intestine to clarify their respective absorption sites. We then investigated the interactions between FSVs during their uptake by Caco-2 cells. Our data show that vitamin A was mostly absorbed in the mouse proximal intestine, while vitamin D was absorbed in the median intestine, and vitamin E and K in the distal intestine. Significant competitive interactions for uptake were then elucidated among vitamin D, E and K, supporting the hypothesis of common absorption pathways. Vitamin A also significantly decreased the uptake of the other FSVs but, conversely, its uptake was not impaired by vitamins D and K and even promoted by vitamin E. These results should be taken into account, especially for supplement formulation, to optimise FSV absorption. PMID:25442537

Goncalves, Aurélie; Roi, Stéphanie; Nowicki, Marion; Dhaussy, Amélie; Huertas, Alain; Amiot, Marie-Josèphe; Reboul, Emmanuelle

2015-04-01

331

Vitamin D: The “sunshine” vitamin  

PubMed Central

Vitamin D insufficiency affects almost 50% of the population worldwide. An estimated 1 billion people worldwide, across all ethnicities and age groups, have a vitamin D deficiency (VDD). This pandemic of hypovitaminosis D can mainly be attributed to lifestyle (for example, reduced outdoor activities) and environmental (for example, air pollution) factors that reduce exposure to sunlight, which is required for ultraviolet-B (UVB)-induced vitamin D production in the skin. High prevalence of vitamin D insufficiency is a particularly important public health issue because hypovitaminosis D is an independent risk factor for total mortality in the general population. Current studies suggest that we may need more vitamin D than presently recommended to prevent chronic disease. As the number of people with VDD continues to increase, the importance of this hormone in overall health and the prevention of chronic diseases are at the forefront of research. VDD is very common in all age groups. As few foods contain vitamin D, guidelines recommended supplementation at suggested daily intake and tolerable upper limit levels. It is also suggested to measure the serum 25-hydroxyvitamin D level as the initial diagnostic test in patients at risk for deficiency. Treatment with either vitamin D2 or vitamin D3 is recommended for deficient patients. A meta-analysis published in 2007 showed that vitamin D supplementation was associated with significantly reduced mortality. In this review, we will summarize the mechanisms that are presumed to underlie the relationship between vitamin D and understand its biology and clinical implications. PMID:22629085

Nair, Rathish; Maseeh, Arun

2012-01-01

332

Organo-modified layered double hydroxide-catalyzed Fenton-like ultra-weak chemiluminescence for specific sensing of vitamin B?? in egg yolks.  

PubMed

In general, the chemiluminescence (CL) sensing of vitamin B12 is achieved by determining Co(II) liberated from acidified vitamin B12 by a luminol system. However, the luminol system for sensing vitamin B12 has poor selectivity due to serious interference from other metal ions. In this study, as a novel CL amplifier of the Co(II)+H2O2+OH(-) ultra-weak CL reaction (Fenton-like system), dodecylbenzene sulfonate (DBS)-layered double hydroxides (LDHs) have been applied to the specific determination of vitamin B12 by liberating Co(II). The CL intensity increased with increasing the concentration of vitamin B12 in a wide range from 1.0 ng mL(-1) to 5 ?g mL(-1) with a detection limit of 0.57 ng mL(-1) (S/N=3). The proposed method has been successfully applied to determine vitamin B12 in egg yolk with simple procedures, shorter time and higher selectivity. Recoveries from spiked real samples were 96-103%. The results of the proposed method for sensing vitamin B12 in real samples were agreed with those obtained by the standard inductively coupled plasma mass spectrometry (ICP-MS) method. To the best of our knowledge, this is the first report on the CL sensing of vitamin B12 with high selectivity in the absence of luminol. PMID:25127574

Zhang, Lijuan; Rong, Wanqi; Lu, Chao; Zhao, Lixia

2014-11-01

333

Vitamin K  

Technology Transfer Automated Retrieval System (TEKTRAN)

A wide range of analytical techniques are available for the detection, quantitation, and evaluation of vitamin K in foods. The methods vary from simple to complex depending on extraction, separation, identification and detection of the analyte. Among the extraction methods applied for vitamin K anal...

334

Vitamin K  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin K was identified in the early 1930’s when it was shown to be essential for normal blood coagulation. Phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone) found in green plants is the major source of the vitamin. Large amounts of menaquinones with lengthy side chains are also synthesized in...

335

Pantothenic acid (Vitamin B5)  

MedlinePLUS

... acid is frequently used in combination with other B vitamins in vitamin B complex formulations. Vitamin B complex generally includes vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin/niacinamide), vitamin ...

336

Vitamin A  

MedlinePLUS

... also known as retinol because it produces the pigments in the retina of the eye. Vitamin A ... some fortified foods. Carotenoids are dark-colored dyes (pigments) found in plant foods that can turn into ...

337

Vitamin C  

MedlinePLUS

... in pure crystalline form in 1927 by Nobel Prize winner Albert Szent-Gyorgyi. He published his paper ... disease prevention. In the 1970s, two-time Nobel Prize winner Linus Pauling advocated large doses of vitamin ...

338

Vitamin A  

MedlinePLUS

... amount of preformed vitamin A in their products. Smokers should avoid high-dose single supplements of beta-carotene, since some randomized trials in smokers have linked high dose supplementation with increased lung ...

339

Vitamin E  

MedlinePLUS

... Vitamin E is found in the following foods: Vegetable oils (such as wheat germ, sunflower, safflower, corn, and soybean oils) Nuts (such as almonds, peanuts, and hazelnuts/filberts) ... (such as spinach and broccoli) Fortified breakfast cereals, ...

340

Metabolic programming of offspring by vitamin B12, folate imbalance during pregnancy  

Technology Transfer Automated Retrieval System (TEKTRAN)

With two reports in the current issue of Diabetologia, C. S. Yajnik and his international cast of collaborators have created conceptual bridges between some of the most important global public health challenges of our time: obesity (or is it adiposity?), fetal or early life origins of adult disease,...

341

MECHANISTIC STUDIES ON THE VITAMIN B12-CATALYZED DECHLORINATION OF CHLORINATED ALKENES. (U915562)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

342

Inhibition of vitamin B12-dependent microbial growth by nitrous oxide  

SciTech Connect

In methionine-free media, nitrous oxide inhibits the growth of an auxotrophic strain of Escherichia coli lacking a cobalamin-independent pathway for the de novo synthesis of methionine. Prototrophic E. coli is similarly inhibited by nitrous oxide if the cobalamin-independent pathway is selectively depressed by sulfanilamide. Nitrous oxide thus effectively inactivates cobalamin-dependent 5-methyltetrahydrofolate-homocysteine methyltransferase in intact bacteria.

Alston, T.A. (Massachusetts General Hospital, Boston (USA))

1991-01-01

343

POLYCHLORINATED BIPHENYL REDUCTIVE DECHLORINATION BY VITAMIN B12S: THERMODYNAMICS AND REGIOSPECIFICITY. (R825689C017)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

344

The importance of vitamin B12 and unidentified factors in the nutrition of the domestic fowl  

E-print Network

(*32), Reimann and Fritsch (*34), Fouts, et al. (*35) and Cheney ( T35) have shown that the anti- anemic properties of liver preparations can be greatly increased by incubation with gastric juice, gastric mucosa or mucosal scrapings from human.... Through Chem. Eng. News., 27: 3487. Fouts, P. J . , 0. M. Helmer, and L. G. Zerfas 1935 Quantitative studies on increased potency of liver extract by incubation with normal human gastric juice. Ann. Int. Med., 8: 790. Frommeyer, W. B ., Jr ., T. D...

Olcese, Orlando

2013-10-04

345

Low maternal vitamin B12 status is associated with intrauterine growth retardation in urban South Indians  

Microsoft Academic Search

Objective:To assess the maternal sociodemographic, anthropometric, dietary and micronutrient status in apparently healthy pregnant women in order to determine their associations with intrauterine growth retardation (IUGR).Design:Prospective observational study.Setting:Bangalore City, India.Subjects:A total of 478 women were recruited at 12.9±3.3 weeks of gestation and followed up at the first, second and third trimesters of pregnancy and at delivery. The dropout rate was

S Muthayya; A V Kurpad; C P Duggan; R J Bosch; P Dwarkanath; A Mhaskar; R Mhaskar; A Thomas; M Vaz; S Bhat; W W Fawzi

2006-01-01

346

Observations on the vitamin B12 binding substance of egg yolk  

E-print Network

A, Thesis "yi""ih eQ Le Qhe *~pe'j ~'j e *ese' 1 A: gicQ1+MQ1'5716';, :!eshs'51Q91, . P911e:, :, 6 'Qf Text's , i~ yeW~ial fM "i11'. e~h. i=" ". '. he ie~ixemenPs 'e= -~he Pi~w'x s. pZ"' ' ACKhG~KEEC~L::ai?iT The anterior w1shes to, express...'~ fee Wtagdns, Such a eesipett ?K~s tgh1biem" ts egyke~ as a tec4 ty' 'Q)@ NeeeoQtst te Mveetieaee wacke @ACA54 ". i%tace(te feocxi~ Af esse' d~eveeeit vCtei~~ ze & %@XX kAcRilxl tt&e 8414 6vMg5 aet as &MA&iteee ef' y~o', . amebic ?eke (Rwbseisix...

Ener, Huseyin Siret

2012-06-07

347

Assessment of Plasma Homocysteine, Folate and Vitamin B12 Levels in Children with Type 1 Diabetes  

Microsoft Academic Search

3 Abstract: Hyperhomocysteinemia has been established as a risk factor for cardiovascular disease i n t ype 1 diabetic patients. The present work aimed to investigate fasting total plasma homocysteine concentrations in c hildren and adolescents w ith type 1diabetes. F orty-six children with type 1diabetes (2 3 with microalbuminuria and 23 without microalbuminuria) and 23 subjects of an age-

Hassan M. Salama Hassan; Mohamed Anwar; Amany Mohamed

2009-01-01

348

The influence of cobalt/vitamin B12 deficiency as a stressor affecting adrenal cortex  

E-print Network

measurement and the pituitary gland and corpus luteum for LH and progesterone determinations, respectively corticosteroids were persistently high in cobalt-deficient goats as compared to the controls, and pituitary LH to irregular cycles, the action site being located in the hypothalamo-pituitary axis. Introduction. The effects

Paris-Sud XI, Université de

349

Common variants of FUT2 are associated with plasma vitamin B12 levels  

Technology Transfer Automated Retrieval System (TEKTRAN)

A genome-wide scan is a way to distinguish small differences in the genetic makeup of individuals. It is also a way which distinguishes if a mutation in any particular gene is widespread or it is "polymorphic." The value of these analyses lies in the identification of genes that could influence a th...

350

Influence of vitamin B auxotrophy on nitrogen metabolism in eukaryotic phytoplankton  

PubMed Central

While nitrogen availability is known to limit primary production in large parts of the ocean, vitamin starvation amongst eukaryotic phytoplankton is becoming increasingly recognized as an oceanographically relevant phenomenon. Cobalamin (B12) and thiamine (B1) auxotrophy are widespread throughout eukaryotic phytoplankton, with over 50% of cultured isolates requiring B12 and 20% requiring B1. The frequency of vitamin auxotrophy in harmful algal bloom species is even higher. Instances of colimitation between nitrogen and B vitamins have been observed in marine environments, and interactions between these nutrients have been shown to impact phytoplankton species composition. This review surveys available data, including relevant gene expression patterns, to evaluate the potential for interactive effects of nitrogen and vitamin B12 and B1 starvation in eukaryotic phytoplankton. B12 plays essential roles in amino acid and one-carbon metabolism, while B1 is important for primary carbohydrate and amino acid metabolism and likely useful as an anti-oxidant. Here we will focus on three potential metabolic interconnections between vitamin, nitrogen, and sulfur metabolism that may have ramifications for the role of vitamin and nitrogen scarcities in driving ocean productivity and species composition. These include: (1) B12, B1, and N starvation impacts on osmolyte and antioxidant production, (2) B12 and B1 starvation impacts on polyamine biosynthesis, and (3) influence of B12 and B1 starvation on the diatom urea cycle and amino acid recycling through impacts on the citric acid cycle. We evaluate evidence for these interconnections and identify oceanographic contexts in which each may impact rates of primary production and phytoplankton community composition. Major implications include that B12 and B1 deprivation may impair the ability of phytoplankton to recover from nitrogen starvation and that changes in vitamin and nitrogen availability may synergistically impact harmful algal bloom formation. PMID:23091473

Bertrand, Erin M.; Allen, Andrew E.

2012-01-01

351

Tissue vitamin concentrations are maintained constant by changing the urinary excretion rate of vitamins in rats' restricted food intake.  

PubMed

We previously reported that mild food restriction induces a reduction in tryptophan-nicotinamide conversion, which helps to explain why death secondary to pellagra is pandemic during the hungry season. In this study, we investigated the levels of B-group vitamins in the liver, kidney, blood, and urine in rats that underwent gradual restriction of food intake (80, 60, 40, and 20% restriction vs. ad libitum food intake). No significant differences in the B-group vitamin concentrations (mol/g tissue) in the liver and kidney were observed at any level of food restriction. However, the urine excretion rates exhibited some characteristic phenomena that differed by vitamin. These results show that the tissue concentrations of B-group vitamins were kept constant by changing the urinary elimination rates of vitamins under various levels of food restriction. Only vitamin B12 was the only (exception). PMID:25117986

Shibata, Katsumi; Fukuwatari, Tsutomu

2014-12-01

352

TD-DFT insight into photodissociation of the Co-C bond in coenzyme B12  

PubMed Central

Coenzyme B12 (AdoCbl) is one of the most biologically active forms of vitamin B12, and continues to be a topic of active research interest. The mechanism of Co-C bond cleavage in AdoCbl, and the corresponding enzymatic reactions are however, not well understood at the molecular level. In this work, time-dependent density functional theory (TD-DFT) has been applied to investigate the photodissociation of coenzyme B12. To reduce computational cost, while retaining the major spectroscopic features of AdoCbl, a truncated model based on ribosylcobalamin (RibCbl) was used to simulate Co-C photodissociation. Equilibrium geometries of RibCbl were obtained by optimization at the DFT/BP86/TZVP level of theory, and low-lying excited states were calculated by TD-DFT using the same functional and basis set. The calculated singlet states, and absorption spectra were simulated in both the gas phase, and water, using the polarizable continuum model (PCM). Both spectra were in reasonable agreement with experimental data, and potential energy curves based on vertical excitations were plotted to explore the nature of Co-C bond dissociation. It was found that a repulsive 3(?Co?C ? ?*Co?C) triplet state became dissociative at large Co-C bond distance, similar to a previous observation for methylcobalamin (MeCbl). Furthermore, potential energy surfaces (PESs) obtained as a function of both Co-CRib and Co-NIm distances, identify the S1 state as a key intermediate generated during photoexcitation of RibCbl, attributed to a mixture of a metal-to-ligand charge transfer (MLCT) and a ? bonding-ligand charge transfer (SBLCT) states. PMID:24790969

Liu, Hui; Kornobis, Karina; Lodowski, Piotr; Jaworska, Maria; Kozlowski, Pawel M.

2014-01-01

353

Harvard study finds folic acid, vitamins B6 and 12 do not affect colorectal adenoma risk  

Cancer.gov

Combined folic acid, vitamin B6 and vitamin B12 supplements had no statistically significant effect on the risk of colorectal adenoma among women who were at high risk for cardiovascular disease, according to a Harvard Medical School study published October 12 in the Journal of the National Cancer Institute. The Harvard Medical School is a component of the Dana-Farber Cancer Institute.

354

A Novel Class of Modular Transporters for Vitamins in Prokaryotes  

Microsoft Academic Search

The specific and tightly controlled transport of numerous nutrients and metabolites across cellular membranes is crucial to all forms of life. However, many of the transporter proteins involved have yet to be identified, including the vitamin transporters in various human pathogens, whose growth depends strictly on vitamin uptake. Comparative analysis of the ever-growing collection of microbial genomes coupled with experimental

Dmitry A. Rodionov; Peter Hebbeln; Aymerick Eudes; Josy ter Beek; Irina A. Rodionova; Guus B. Erkens; Dirk J. Slotboom; Mikhail S. Gelfand; Andrei L. Osterman; Andrew D. Hanson; Thomas Eitinger

2009-01-01

355

Mapping the functional domains of TCblR/CD320, the receptor for cellular uptake of transcobalamin-bound cobalamin.  

PubMed

The membrane receptor TCblR/CD320 binds transcobalamin (TC) saturated with vitamin B12 [cobalamin (Cbl)] and mediates cellular uptake of the vitamin. The specificity of TC for Cbl and of the receptor for TC-Cbl ensures efficient uptake of Cbl into cells. The high-affinity interaction of TCblR with TC-Cbl (Ka=10 nM(-1)) was investigated using deletions and mutations of amino acid sequences in TCblR. Only the extracellular region (aa 32-229) is needed for TC-Cbl binding, but the N-glycosylation sites (N126, N195, and N213) are of no importance for this function. Deleting the cysteine-rich region (aa 95-141) that separates the two low-density lipoprotein receptor type A (LDLR-A) domains does not affect TC-Cbl binding (Ka = 19-24 nM(-1)). The two LDLR-A domains (aa 54-89 and 132-167) with the negatively charged acidic residues involved in Ca(2+) binding are critical determinants of ligand binding. The cytoplasmic tail is apparently crucial for internalization of the ligand. Within this region, the RPLGLL motif and the PDZ binding motifs (QERL/KESL) appear to be involved in initiating and completing the process of ligand internalization. Mutations and deletions of these regions involved in binding and internalization of TC-Cbl are likely to produce the biochemical and clinical phenotype of Cbl deficiency. PMID:23603833

Jiang, Wenxia; Nakayama, Yasumi; Sequeira, Jeffrey M; Quadros, Edward V

2013-08-01

356

Uptake and accumulation of B-group vitamers in Saccharomyces cerevisiae in ethanol-stat fed-batch culture.  

PubMed

The uptake and accumulation of the B-group vitamins thiamine, riboflavin, nicotinamide, pantothenic acid and pyridoxine in Saccharomyces cerevisiae was studied by gradually increasing the specific dosage of vitamins in an ethanol-stat fed-batch culture. Thiamine, nicotinamide, pantothenic acid, and pyridoxine were almost completely taken up at low vitamin dosages. Thiamine was determined to be the major accumulating form of vitamin B1 while most of the assimilated nicotinamide and pantothenic acid accumulated in cofactor forms. Despite the obvious uptake of pyridoxine, accumulation of B6 vitamers was not observed. In contrast with the other vitamins studied, riboflavin began accumulating in the culture medium immediately after vitamin addition was initiated. By the end of the experiment, the apparent uptake of all vitamins exceeded their accumulation in the cells. Variations in the growth rate of yeast at different vitamin dosages demonstrate the importance of balancing the vitamins in the media during cultivation. PMID:24781266

Paalme, T; Kevvai, K; Vilbaste, A; Hälvin, K; Nisamedtinov, I

2014-09-01

357

Vitamin D: An overview of vitamin D status and intake in Europe  

PubMed Central

In recent years, there have been reports suggesting a high prevalence of low vitamin D intakes and vitamin D deficiency or inadequate vitamin D status in Europe. Coupled with growing concern about the health risks associated with low vitamin D status, this has resulted in increased interest in the topic of vitamin D from healthcare professionals, the media and the public. Adequate vitamin D status has a key role in skeletal health. Prevention of the well-described vitamin D deficiency disorders of rickets and osteomalacia are clearly important, but there may also be an implication of low vitamin D status in bone loss, muscle weakness and falls and fragility fractures in older people, and these are highly significant public health issues in terms of morbidity, quality of life and costs to health services in Europe. Although there is no agreement on optimal plasma levels of vitamin D, it is apparent that blood 25-hydroxyvitamin D [25(OH)D] levels are often below recommended ranges for the general population and are particularly low in some subgroups of the population, such as those in institutions or who are housebound and non-Western immigrants. Reported estimates of vitamin D status within different European countries show large variation. However, comparison of studies across Europe is limited by their use of different methodologies. The prevalence of vitamin D deficiency [often defined as plasma 25(OH)D <25?nmol/l] may be more common in populations with a higher proportion of at-risk groups, and/or that have low consumption of foods rich in vitamin D (naturally rich or fortified) and low use of vitamin D supplements. The definition of an adequate or optimal vitamin D status is key in determining recommendations for a vitamin D intake that will enable satisfactory status to be maintained all year round, including the winter months. In most European countries, there seems to be a shortfall in achieving current vitamin D recommendations. An exception is Finland, where dietary survey data indicate that recent national policies that include fortification and supplementation, coupled with a high habitual intake of oil-rich fish, have resulted in an increase in vitamin D intakes, but this may not be a suitable strategy for all European populations. The ongoing standardisation of measurements in vitamin D research will facilitate a stronger evidence base on which policies can be determined. These policies may include promotion of dietary recommendations, food fortification, vitamin D supplementation and judicious sun exposure, but should take into account national, cultural and dietary habits. For European nations with supplementation policies, it is important that relevant parties ensure satisfactory uptake of these particularly in the most vulnerable groups of the population.

Spiro, A; Buttriss, J L

2014-01-01

358

Vitamins, Minerals, and Mood  

ERIC Educational Resources Information Center

In this article, the authors explore the breadth and depth of published research linking dietary vitamins and minerals (micronutrients) to mood. Since the 1920s, there have been many studies on individual vitamins (especially B vitamins and Vitamins C, D, and E), minerals (calcium, chromium, iron, magnesium, zinc, and selenium), and vitamin-like…

Kaplan, Bonnie J.; Crawford, Susan G.; Field, Catherine J.; Simpson, J. Steven A.

2007-01-01

359

The Role of B Vitamins in Marine Biogeochemistry  

NASA Astrophysics Data System (ADS)

The soluble B vitamins (B1, B7, and B12) have long been recognized as playing a central metabolic role in marine phytoplankton and bacteria; however, the importance of these organic external metabolites in marine ecology has been largely disregarded, as most research has focused on inorganic nutrients and trace metals. Using recently available genomic data combined with culture-based surveys of vitamin auxotrophy (i.e., vitamin requirements), we show that this auxotrophy is widespread in the marine environment and occurs in both autotrophs and heterotrophs residing in oligotrophic and eutrophic environments. Our analysis shows that vitamins originate from the activities of some bacteria and algae and that taxonomic changes observed in marine phytoplankton communities could be the result of their specific vitamin requirements and/or vitamin availability. Dissolved vitamin concentration measurements show that large areas of the world ocean are devoid of B vitamins, suggesting that vitamin limitation could be important for the efficiency of carbon and nitrogen fixation in those regions.

Sañudo-Wilhelmy, Sergio A.; Gómez-Consarnau, Laura; Suffridge, Christopher; Webb, Eric A.

2014-01-01

360

Bioavailability of Oil-Based and ? -Lactoglobulin-Complexed Vitamin A in a Rat Model.  

PubMed

? -Lactoglobulin is capable of binding fat-soluble compounds including vitamin A palmitate and is suggested to specifically enhance intestinal uptake of retinol. In this study, bioavailability of a vitamin-A-retinyl palmitate complex in skim milk and in water-based liquids was investigated in vitamin-A-depleted rats. First, rats were fed a vitamin-A-free pellet diet for 6?wk and were thereafter gavage-fed with vitamin A in oil, vitamin-A- ? -lactoglobulin complex, vitamin A in oil + skim milk, and vitamin-A- ? -lactoglobulin + skim milk for 2?wk and 42?wk. Vitamin A repletion, as judged by vitamin A accumulation in serum and liver, occurred in all the treatments. Vitamin-A- ? -lactoglobulin complex treatments had statistical equivalence with oil-based vitamin A treatments. In a second experiment, vitamin-A-depleted rats were fed UHT-processed skim milk fortified with either oil-based or freeze-dried ? -lactoglobulin-complexed retinyl palmitate. Liver and serum vitamin A were analyzed by HPLC to indicate vitamin A status in the rats. Results showed no significant difference in bioavailability of retinyl palmitate from milk made with either regular oil-based or ? -lactoglobulin-complexed fortifiers. The vitamin-A- ? -lactoglobulin complex, being water soluble, may be useful for fortification of nonfat products. PMID:24967254

Liu, Ying; Shaw, Ju-Jean; Swaisgood, Harold E; Allen, Jonathan C

2013-01-01

361

Intra- and inter-individual variations of blood and urinary water-soluble vitamins in Japanese young adults consuming a semi-purified diet for 7 days.  

PubMed

We have previously reported the levels of water-soluble vitamins in the blood and urine of Japanese young adults. In the present paper, to assess the variations in these water-soluble vitamin markers during the above experiment, we comprehensively determined the intra- and inter-individual variations of blood and urinary water-soluble vitamins to exactly the same amount of water-soluble vitamin intakes in the same experiment. The blood samples before breakfast and the 24-h urine samples were periodically collected from Japanese college male (n=10) and female (n=10) students consuming a semi-purified diet with water-soluble vitamins based on Japanese Dietary Reference Intakes for 7 d, and the intra- and inter-individual variations of blood and urinary water-soluble vitamins or their metabolites in blood and urine samples after adaptation were calculated. Although urinary excretion of vitamin B(12) and vitamin C showed high intra-individual variations in both males and females, other urinary vitamins and all blood vitamins showed less than 20% of within-subject coefficients of variance in either male or female. Those showing more than 20% of between-subject coefficients of variances in both male and female were blood vitamin B(6), vitamin B(12) and folate levels, and urinary vitamin B(1), vitamin B(2), vitamin B(12), nicotinamide metabolites, pantothenic acid, biotin and vitamin C. These results showed that oral administration of constant of water-soluble vitamins generally decreased intra-individual variation, while individual differences in urinary vitamin excretion were observed. PMID:20086315

Shibata, Katsumi; Fukuwatari, Tsutomu; Watanabe, Toshiaki; Nishimuta, Mamoru

2009-12-01

362

Vitamins and Minerals  

MedlinePLUS

... gov . Nutrition for Everyone Nutrition Topics Share Compartir Vitamins and Minerals Vitamins are organic substances (made by plants or animals), ... humans absorb minerals from the plants they eat. Vitamins and minerals are nutrients that your body needs ...

363

Multiple vitamin overdose  

MedlinePLUS

... Mood changes Irritability Skin and hair: Flushing from niacin (vitamin B3) Dry cracking skin Itching , burning skin, ... Niacin flush (vitamin B3) is uncomfortable, but lasts only 2 to 8 hours. Vitamins A and D ...

364

Facts about Vitamin D  

MedlinePLUS

... food, supplements, and sunlight. Food Eggs, sardines, and salmon contain vitamin D. Most fluid milk and some ... VitaminD/ Nutrition.gov http://nutrition.gov Figure 2. Salmon is a very rich source of vitamin D, ...

365

[Group B vitamins in some typical Italian cheese: Parmigiano-reggiano, Pecorino romano and Gorgonzola (author's transl)].  

PubMed

The levels of Vitamins B1, B2, B6, B12, PP and Calcium pantothenate were determined in typical italian cheese: Parmigiano-reggiano, Pecorino romano and Gorgonzola. The authors avaluated vitamin contents different from product; to product these differences being possibly due to both similar quantitative diversities of the milk, used and to particular variations associated with the processing techniques. PMID:134450

Minoccheri, F; Brusco, A; Massari, M

1975-01-01

366

Cholecalciferol Modulates Plasma Phosphate But Not Plasma Vitamin D Levels and Intestinal Phosphate Absorption in Rainbow Trout ( Oncorhynchus mykiss)  

Microsoft Academic Search

Since the vitamin D endocrine system modulates phosphorus homeostasis and regulates inorganic phosphate (Pi) uptake by the small intestine in mammals and birds, we determined the effects of dietary cholecalciferol (vitamin D3) on Piuptake by the small intestine, Piconcentrations in the plasma, Piconcentrations in the intestinal lumen, intestinal weights, liver weights, and concentrations of vitamin D metabolites in the plasma

Enrique M. Avila; Sandra P. Basantes; Ronaldo P. Ferraris

1999-01-01

367

Factors Influencing the Diversity of Iron Uptake Systems in Aquatic Microorganisms  

PubMed Central

Iron (Fe) is an essential micronutrient for many processes in all living cells. Dissolved Fe (dFe) concentrations in the ocean are of the order of a few nM, and Fe is often a factor limiting primary production. Bioavailability of Fe in aquatic environments is believed to be primarily controlled through chelation by Fe-binding ligands. Marine microbes have evolved different mechanisms to cope with the scarcity of bioavailable dFe. Gradients in dFe concentrations and diversity of the Fe-ligand pool from coastal to open ocean waters have presumably imposed selection pressures that should be reflected in the genomes of microbial communities inhabiting the pelagic realm. We applied a hidden Markov model (HMM)-based search for proteins related to cellular iron metabolism, and in particular those involved in Fe uptake mechanisms in 164 microbial genomes belonging to diverse taxa and occupying different aquatic niches. A multivariate statistical approach demonstrated that in phototrophic organisms, there is a clear influence of the ecological niche on the diversity of Fe uptake systems. Extending the analyses to the metagenome database from the Global Ocean Sampling expedition, we demonstrated that the Fe uptake and homeostasis mechanisms differed significantly across marine niches defined by temperatures and dFe concentrations, and that this difference was linked to the distribution of microbial taxa in these niches. Using the dN/dS ratios (which signify the rate of non-synonymous mutations) of the nucleotide sequences, we identified that genes encoding for TonB, Ferritin, Ferric reductase, IdiA, ZupT, and Fe2+ transport proteins FeoA and FeoB were evolving at a faster rate (positive selection pressure) while genes encoding ferrisiderophore, heme and Vitamin B12 uptake systems, siderophore biosynthesis, and IsiA and IsiB were under purifying selection pressure (evolving slowly). PMID:23087680

Desai, Dhwani K.; Desai, Falguni D.; LaRoche, Julie

2012-01-01

368

Vitamin and mineral requirements  

E-print Network

Vitamin and mineral requirements in human nutrition Second edition Please go to the Table/WHO Expert Consultation on Human Vitamin and Mineral Requirements (1998 : Bangkok, Thailand). Vitamin, 21­30 September 1998. 1.Vitamins -- standards 2.Micronutrients -- standards 3.Trace elements

Laughlin, Robert B.

369

Riboflavin (Vitamin B2)  

MedlinePLUS

Riboflavin is a B vitamin. It can be found in certain foods such as milk, meat, eggs, nuts, enriched flour, and green vegetables. Riboflavin is frequently used in combination with other B vitamins in vitamin B complex products. Vitamin B complex ...

370

The role of homocysteine-lowering B-vitamins in the primary prevention of cardiovascular disease.  

PubMed

Cardiovascular disease (CVD) is the leading cause of mortality in the Western world. The effort of research should aim at the primary prevention of CVD. Alongside statin therapy, which is maintained to be an effective method of CVD prevention, there are alternative methods such as vitamin B substitution therapy with folic acid (FA), and vitamins B12 and B6 . B-vitamins may inhibit atherogenesis by decreasing the plasma level of homocysteine (Hcy)-a suspected etiological factor for atherosclerosis-and by other mechanisms, primarily through their antioxidant properties. Although Hcy-lowering vitamin trials have failed to demonstrate beneficial effects of B-vitamins in the prevention of CVD, a meta-analysis and stratification of a number of large vitamin trials have suggested their effectiveness in cardiovascular prevention (CVP) in some aspects. Furthermore, interpretation of the results from these large vitamin trials has been troubled by statin/aspirin therapy, which was applied along with the vitamin substitution, and FA fortification, both of which obscured the separate effects of vitamins in CVP. Recent research results have accentuated a new approach to vitamin therapy for CVP. Studies undertaken with the aim of primary prevention have shown that vitamin B substitution may be effective in the primary prevention of CVD and may also be an option in the secondary prevention of disease if statin therapy is accompanied by serious adverse effects. Further investigations are needed to determine the validity of vitamin substitution therapy before its introduction in the protocol of CVD prevention. PMID:24571382

Debreceni, Balazs; Debreceni, Laszlo

2014-06-01

371

Effects of Vitamins on Chromium(VI)- Induced Damage  

E-print Network

The effects of vitamin E and vitamin B2 on DNA damage and cellular reduction of chromium(VI) were investigated using Chinese hamster V-79 cells. Pretreatment with a-tocopherol succinate (vitamin E) resulted in a decrease of DNA single-strand breaks produced by Na2CrO4, while similar treatment with riboflavin (vitamin B2) enhanced levels of DNA breaks. In contrast, levels of DNA-protein crosslinks induced by Na2CrO4 were unaffected by these vitamins. Electron spin resonance (ESR) studies showed that incubation of cells with Na2CrO4 resulted in the formation of both chromium(V) and chromium(III) complexes, and cellular pretreatment with vitamin E reduced the level of the chromium(V) complex, whereas pretreatment with vitamin B2 enhanced the level of this intermediate. However, the levels of chromium(III) were unchanged by these vitamins. The uptake of chromate was not affected by vitamin E or vitamin B2, nor were the levels of glutathione or glutathione reductase activity, which are both capable of reducing chromate. ESR studies demonstrated that a chromium(V) species was formed by the reaction of Na2CrO4 with vitamin B2 and that vitamin B2 enhanced the formation of hydroxyl radicals during the reaction of Na2CrO4 and hydrogen peroxide. Treatment of cells with Na2CrO4 resulted in a decrease of glutathione reductase activity, and pretreatment with vitamin E restored the enzyme activity suppressed by this metal. However, pretreatment with vitamin B % enhanced the inhibition of this enzyme by Na2CrO4. Using a colony-forming assay, pretreatment with vitamin E dramatically decreased the cytotoxicity of Na2CrO4, while pretreatment with vitamin B2 was found to result in only a decrease of cell lethality of this metal. These results indicate that vitamin E and vitamin B2 are capable of altering the biological effects of carcinogenic chromium(VI) compounds, possibly through their abilities to modify levels of chromium (V) in cells. The results also suggest that chromate-induced cytotoxicity may not be directly correlated with the genotoxic effects of this metal. The importance of the role of vitamins in chromate-induced toxicity is discussed.

Masayasu Sugiyama

372

B complex vitamin patterns in geriatric and young adult inpatients with major depression.  

PubMed

This study compared the B complex vitamin status at time of admission of 20 geriatric and 16 young adult non-alcoholic inpatients with major depression. Twenty-eight percent of all subjects were deficient in B2 (riboflavin), B6 (pyridoxine), and/or B12 (cobalamin), but none in B1 (thiamine) or folate. The geriatric sample had significantly higher serum folate levels. Psychotic depressives had lower B12 than did non-psychotic depressives. Poorer blood vitamin status was not associated with higher scores on the Hamilton Depression Rating Scale or lower scores on the Mini-Mental State Examination in either age group. The data support the hypothesis that poorer status in certain B vitamins is present in major depression, but blood measures may not reflect central nervous system vitamin function or severity of affective syndromes as measured by the assays and scales in the present study. PMID:2005338

Bell, I R; Edman, J S; Morrow, F D; Marby, D W; Mirages, S; Perrone, G; Kayne, H L; Cole, J O

1991-03-01

373

17 CFR 240.3b-12 - Definition of OTC derivatives dealer.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Definition of OTC derivatives dealer. 240.3b-12 Section 240...Definitions § 240.3b-12 Definition of OTC derivatives dealer. The term OTC derivatives dealer means any dealer that is...

2010-04-01

374

17 CFR 270.8b-12 - Requirements as to paper, printing and language.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Requirements as to paper, printing and language. 270.8b-12 Section 270.8b-12 Commodity...ACT OF 1940 § 270.8b-12 Requirements as to paper, printing and language. (a) Registration statements and...

2012-04-01

375

17 CFR 270.8b-12 - Requirements as to paper, printing and language.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Requirements as to paper, printing and language. 270.8b-12 Section 270.8b-12 Commodity...ACT OF 1940 § 270.8b-12 Requirements as to paper, printing and language. (a) Registration statements and...

2014-04-01

376

17 CFR 270.8b-12 - Requirements as to paper, printing and language.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Requirements as to paper, printing and language. 270.8b-12 Section 270.8b-12 Commodity...ACT OF 1940 § 270.8b-12 Requirements as to paper, printing and language. (a) Registration statements and...

2013-04-01

377

Liquid-liquid distribution of B group vitamins in polyethylene glycol-based systems  

NASA Astrophysics Data System (ADS)

General regularities of the liquid-liquid distribution of B1, B2, B6, and B12 vitamins in aqueous polyethylene glycol (PEG-2000, PEG-5000) solution-aqueous salt solution systems are studied. The influence of the salting-out agent, the concentration of the polymer, and its molecular weight on the distribution coefficients and recovery factors of the vitamins are considered. Equations relating the distribution coefficients (log D) to the polymer concentration are derived.

Korenman, Ya. I.; Zykov, A. V.; Mokshina, N. Ya.

2011-05-01

378

Dietary intakes and vitamin status of a sample of homeless people in Paris  

Microsoft Academic Search

Objective: To determine nutritional intake and vitamin status in a sample of homeless people who had been on the streets of Paris for more than 2 y.Design: The nutritional status was evaluated by a 24 h recall questionnaire and by assay of circulating levels of vitamins A, B1, B6, B12, C and E.Setting: The study was conducted in four accommodation

L Malmauret; JCh Leblanc; I Cuvelier; Ph Verger

2002-01-01

379

Effect of smoking on serum concentrations of total homocysteine and B vitamins in mid-pregnancy  

Microsoft Academic Search

There are conflicting findings in the literature on the effect of smoking on total homocysteine (tHcy) concentrations in non-pregnant subjects. We evaluated the effect of smoking on serum concentrations of tHcy, folate, vitamin B-12 pyridoxal 5?-phosphate (PLP, a coenzyme form of vitamin B-6) in 196 women at 18 and 30 weeks' gestation. The smokers were defined as those who self-reported

Karla Pagán; Jinrong Hou; Robert L Goldenberg; Suzanne P Cliver; Tsunenobu Tamura

2001-01-01

380

Large-Scale Domain Motions and Pyridoxal-5?-Phosphate Assisted Radical Catalysis in Coenzyme B12-Dependent Aminomutases†  

PubMed Central

Lysine 5,6-aminomutase (5,6-LAM) and ornithine 4,5-aminomutase (4,5-OAM) are two of the rare enzymes that use assistance of two vitamins as cofactors. These enzymes employ radical generating capability of coenzyme B12 (5?-deoxyadenosylcobalamin, dAdoCbl) and ability of pyridoxal-5?-phosphate (PLP, vitamin B6) to stabilize high-energy intermediates for performing challenging 1,2-amino rearrangements between adjacent carbons. A large-scale domain movement is required for interconversion between the catalytically inactive open form and the catalytically active closed form. In spite of all the similarities, these enzymes differ in substrate specificities. 4,5-OAM is highly specific for d-ornithine as a substrate while 5,6-LAM can accept d-lysine and l-?-lysine. This review focuses on recent computational, spectroscopic and structural studies of these enzymes and their implications on the related enzymes. Additionally, we also discuss the potential biosynthetic application of 5,6-LAM. PMID:24562332

Maity, Amarendra Nath; Chen, Yung-Han; Ke, Shyue-Chu

2014-01-01

381

[Vitamin D and neurology].  

PubMed

Vitamin D deficiency is associated with a higher risk of multiple sclerosis and also with a higher relapse rate as well as a higher number of MRI lesions. Elders with vitamin D deficiency have worse cognitive performance. Vitamin D deficiency is a risk factor for developing Alzheimer's disease. Ischemic stroke are more frequent and more severe in patients with low vitamin D levels. Carotid atherosclerosis is more frequent and more severe in patients with vitamin D deficiency. Vitamin D deficiency is associated with a higher risk and worse prognosis of Parkinson's disease. In the different neurological disorders discussed herein, gene polymorphisms that could alter vitamin D metabolism are also associated with a higher incidence or a worse disease prognosis. Despite the links between vitamin D deficiency and the risks of developing neurological disorders, there is, to date, no proof that supplementation could alter the course of these diseases. PMID:24054766

Thouvenot, Éric; Camu, William

2013-10-01

382

Vitamin C and colds  

MedlinePLUS

... popular belief that vitamin C can cure the common cold , the scientific evidence for this is conflicting. Large ... B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev . 2007 Jul 18;(3): ...

383

Vitamin D: beyond bone  

PubMed Central

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells. However, the biological significance of the expression of the VDR in different tissues is not fully understood, and the role of vitamin D in extraskeletal health has been a matter of debate. This report summarizes recent research on the roles for vitamin D in cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging. PMID:23682710

Christakos, Sylvia; Hewison, Martin; Gardner, David G; Wagner, Carol L; Sergeev, Igor N; Rutten, Erica; Pittas, Anastassios G; Boland, Ricardo; Ferrucci, Luigi; Bikle, Daniel D

2013-01-01

384

Vitamin D: beyond bone.  

PubMed

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells. However, the biological significance of the expression of the VDR in different tissues is not fully understood, and the role of vitamin D in extraskeletal health has been a matter of debate. This report summarizes recent research on the roles for vitamin D in cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging. PMID:23682710

Christakos, Sylvia; Hewison, Martin; Gardner, David G; Wagner, Carol L; Sergeev, Igor N; Rutten, Erica; Pittas, Anastassios G; Boland, Ricardo; Ferrucci, Luigi; Bikle, Daniel D

2013-05-01

385

Vitamin B Complex  

MedlinePLUS

... other needed substances. B vitamins are found in plant and animal food sources. Overview B vitamins are ... healthy foods -- with most of them coming from plant sources -- rather than relying on supplements. While it ...

386

B Vitamins Test  

MedlinePLUS

... of this website will be limited. Search Help? B Vitamins Share this page: Was this page helpful? Also ... What are the Recommended Dietary Allowances (RDA) for B vitamins? The RDA for adults, children, and other groups ...

387

Photobiology of Vitamin D  

Microsoft Academic Search

\\u000a The major function of vitamin D (either vitamin D2 or D3) is to maintain healthy bone. Most humans obtain their vitamin D requirement through casual exposure of the skin to solar\\u000a ultraviolet B and from dietary intake. The cutaneous synthesis of vitamin D is a function of 7-dehydrocholesterol concentration\\u000a in epidermis, melanin pigmentation, and the solar zenith angle which depends

Tai C. Chen; Zhiren Lu; Michael F. Holick

388

Vitamin D Pooling Project  

Cancer.gov

The widespread prevalence of low concentrations of vitamin D has triggered great clinical research and public health interest in determining the amount of vitamin D required for optimal health. Specifically, interest in vitamin D as a cancer preventive agent is related to its biological role in cell signaling and because it is present within most tissues of the body.

389

Epilepsy and vitamin D.  

PubMed

Several disorders, both systemic and those of the nervous system, have been linked with vitamin D deficiency. Neurological disorders with a vitamin D link include but are not limited to multiple sclerosis, Alzheimer and Parkinson disease, as well as cerebrovascular disorders. Epilepsy which is the second leading neurological disorder received much less attention. We review evidence supporting a link between vitamin D and epilepsy including those coming from ecological as well as interventional and animal studies. We also assess the literature on the interaction between antiepileptic drugs and vitamin D. Converging evidence indicates a role for vitamin D deficiency in the pathophysiology of epilepsy. PMID:24063762

Holló, András; Clemens, Zsófia; Lakatos, Péter

2014-06-01

390

Towards the synthesis of light-stable coenzyme B 12 analogs  

Microsoft Academic Search

The organometallic complex coenzyme B12 (adenosyl cobalamin, AdoCbl) is not only an essential coenzyme in many biochemical reactions of most if not all living organisms but has lately been shown to play a crucial role in the regulation of B12 related genes. As a consequence, coenzyme B12 has been a target of intense research. However, the investigations of AdoCbl have

Sofia Gallo; Eva Freisinger; Roland K. O. Sigel

2007-01-01

391

Cardiovascular risk in the Asia-Pacific region from a nutrition and metabolic point of view: vitamin deficiencies.  

PubMed

In the past, recommended vitamin or micronutrient intakes have often been based on levels that were adequate to prevent clinical deficiencies from developing. Once these levels were reached, clinicians and nutrition scientists generally attributed little value to higher vitamin intake from supplements or food sources. Evidence has continued to mount showing that the intake and serum concentration of certain vitamins above those necessary to prevent clinical deficiencies, might importantly influence health status. This paper discusses the association of anti-oxidant vitamins and cardiovascular disease, and the association of low intake or serum concentrations of folate, vitamin B6 and vitamin B12, and elevated serum homocysteine, resulting in an increase in vascular disease risk. PMID:11710347

Wattanapenpaiboon, N

2001-01-01

392

TRANSFORMATION OF CARBON TETRACHLORIDE BY REDUCED VITAMIN B12 IN AQUEOUS CYSTEINE SOLUTION. (R825689C073)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

393

Methionine, folic acid, vitamin B b12 sand unidentified factors in the nutrition of the growing chick  

E-print Network

low, rang1ng from O-B~, with an average of 2~ 1n each group. fh 1 t r 1:t1 hf f tt, m1h ~mm. ~m:, 1, ~lt. e f*11. 1d 1. . t1 tr1&. te f t)e ~1 ht k. ". h* vita", in By; & was addod to the diet, the aver'. tge We1ght of the birds w, . s incre... acid (2 mg/kg) was added to the diets of the last four groups. At the end of the 10-week experimental period, 6 repre- sentative birds from each group were killed and the livers and kidneys removed for the purpose of running microbiological assays...

Welch, Billy E

1951-01-01

394

Interrelationship of dietary vitamin B12 or fat with thyrotoxicosis in certain adaptive changes in respiratory enzymes of rat liver  

E-print Network

ppppppp ll Ybu Iu 2SZcSETATSH S6 ?TAOZTH Id N OHa w ZTiACLRppppppp ppppppppppp lx Pu 2SZcSETATSH S63^dpAS4ScgRLS5 ZTiACLRpppppppppppppppp ppppppppplx bu ,icRLTZRHAO5 c5OH S6 aTRAOLF ALROAZRHAE S6 P 1 2 6T4TRH4FpAgFLSASiT4SETE EACaTREu ^ WTLEA Ric...RLTZRHAkppppppppppp Qls bYu ,icRLTZRHAO5 c5OH S6 aTRAOLF ALROAZRHAE S6 Pq. aRp 6T4TRH4FpAgFLSASiT4SETE EACaTREu ^1R4SHa RicRLTZRHAkppppppppp ls bYYu 2SZcSETATSH S6 6OA aR6T4TRHA aTRA .ppppppppppppppppppppppppppppp ly bYYYu,icRLTZRHAO5 V5OH S6 aTRAOLF ALROAZRHAE S6 Ag...

Crawford, Wid Philips

2013-10-04

395

Increased Serum CA15.3 Levels in Patients with Megaloblastic Anemia due to Vitamin B12 Deficiency  

Microsoft Academic Search

Objectives: To estimate the usefulness of serum tumor markers’ monitoring, as predictors of gastric cancer in patients with pernicious anemia. Patients and Methods: We investigated serum levels of carcinoembryonic antigen (CEA), ?-fetal protein, cancer antigen (CA)-19.9, CA-125 and CA-15.3 in 50 patients with pernicious anemia and in 24 healthy controls, matched for age and sex. In 38 patients, the evaluation

Argiris Symeonidis; Alexandra Kouraklis-Symeonidis; Dimitris Apostolopoulos; Evangelia Arvanitopoulou; Nikolaos Giannakoulas; Pavlos Vassilakos; Nicholas Zoumbos

2004-01-01

396

Homocysteine, folate, and vitamin B12 in mild cognitive impairment, Alzheimer disease, and vascular dementia1-3  

Microsoft Academic Search

Background: Evidence supports an independent association be- tween plasma total homocysteine concentrations and the risk of vascular disease. Recent epidemiologic studies reappraised the possibility that vascular risk factors might play a role in the patho- genesis not only of vascular dementia (VaD) but also of Alzheimer disease (AD). Objective: The objective was to investigate the relations of mild cognitive impairment,

Pierluigi Quadri; Claudia Fragiacomo; Rita Pezzati; Enrica Zanda; Gianluigi Forloni; Mauro Tettamanti; Ugo Lucca

397

Sequential changes in propionate metabolism during the development of cobalt\\/vitamin B 12 deficiency in sheep  

Microsoft Academic Search

The changes in propionate metabolism that accompany cobalt deficiency in sheep are described. Two groups of sheep, fed either\\u000a a cobalt sufficient or deficient diet, were given an iv propionate load at intervals during a 14 w experiment. There was a\\u000a tendency towards increased propionate half-life as the animals became cobalt deficient. However, significant changes in the\\u000a area under the

D. Glenn Kennedy; Finbarr P. M. O'Harte; W. John Blanchflower; Desmond A. Rice

1991-01-01

398

Sequential changes in propionate metabolism during the development of cobalt/vitamin B12 deficiency in sheep.  

PubMed

The changes in propionate metabolism that accompany cobalt deficiency in sheep are described. Two groups of sheep, fed either a cobalt sufficient or deficient diet, were given an iv propionate load at intervals during a 14 w experiment. There was a tendency towards increased propionate half-life as the animals became cobalt deficient. However, significant changes in the area under the plasma methylmalonic acid-time curve occurred very early, indicating significant impairment of propionate metabolism. Despite this, the area under the plasma glucose-time curve was unaffected by cobalt deficiency, suggesting that the impairment of propionate metabolism, although significant, is not extensive. PMID:1713046

Kennedy, D G; O'Harte, F P; Blanchflower, W J; Rice, D A

1991-03-01

399

Vitamin D and Asthma  

PubMed Central

Vitamin D deficiency and asthma are common conditions that share risk factors such as African American ethnicity, inner-city residence, and obesity. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between vitamin D status and asthma or asthma morbidity, including potential protective mechanisms such as antiviral effects and enhanced steroid responsiveness. Because most published epidemiologic studies of vitamin D and asthma or asthma morbidity are observational, a recommendation for or against vitamin D supplementation as preventive or secondary treatment for asthma is not advisable and must await results of ongoing clinical trials. Should these trials confirm a beneficial effect of vitamin D, others will be needed to assess the role of vitamin D supplementation to prevent or treat asthma in different groups such as infants, children of school age, and ethnic minorities. PMID:22016447

Paul, Grace; Brehm, John M.; Alcorn, John F.; Holguín, Fernando; Aujla, Shean J.

2012-01-01

400

Vitamin D and immunity  

PubMed Central

Vitamin D deficiency has been linked to an increased risk of a wide range of adverse health outcomes. The active form of vitamin D has an important role in calcium metabolism and in bone mineralisation, but the evidence for other health outcomes is mixed, with the strongest effects seen in the weakest epidemiological study designs. There are plausible pathways whereby vitamin D deficiency can impair immune function, resulting in both overactivity and increased risk of autoimmune disease, as well as immune suppression with poorer resistance to infection. Vitamin D status may influence the bacterial flora that constitute the microbiome and affect immune function through this route. Exposure of the skin to ultraviolet radiation causes the production of a range of chemicals, including vitamin D, and new research is exploring possible vitamin D-independent immunomodulatory pathways. PMID:25580272

Gorman, Shelley; Geldenhuys, Sian; Hart, Prue H.

2014-01-01

401

Vitamin D and Bone  

PubMed Central

All cells comprising the skeleton—chondrocytes, osteoblasts, and osteoclasts—contain both the vitamin D receptor and the enzyme CYP27B1 required for producing the active metabolite of vitamin D, 1,25 dihydroxyvitamin D. Direct effects of 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D on these bone cells have been demonstrated. However, the major skeletal manifestations of vitamin D deficiency or mutations in the vitamin D receptor and CYP27B1, namely rickets and osteomalacia, can be corrected by increasing the intestinal absorption of calcium and phosphate, indicating the importance of indirect effects. On the other hand, these dietary manipulations do not reverse defects in osteoblast or osteoclast function that lead to osteopenic bone. This review discusses the relative importance of the direct versus indirect actions of vitamin D on bone, and provides guidelines for the clinical use of vitamin D to prevent/treat bone loss and fractures. PMID:22544628

2013-01-01

402

Vitamin D and depression.  

PubMed

Vitamin D is an essential nutrient proven to be important for bone health. It has other physiological functions, and there are plausible reasons for investigating vitamin D in depressive disorders. Some cross-sectional clinical and epidemiologic studies, but not all studies, have found that low levels of vitamin D are significantly associated with higher levels of depressive symptoms or with a depression diagnosis. However, cross-sectional studies cannot establish causality, and the methodology of these studies has been criticized. Due to the poor quality of the treatment studies, the effectiveness of vitamin D for depression cannot be adequately assessed. Current evidence does not definitively demonstrate that vitamin D deficiency is a cause of or risk for developing depression or that vitamin D is an effective therapy for depression. PMID:21261225

Howland, Robert H

2011-02-01

403

LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12  

NASA Technical Reports Server (NTRS)

LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six (6) orthogonal faces of the LDEF was correlated, the Interplanetary Dust Experiment clock could be precisely calibrated. The center 1/3rd tray cover is a chromic anodized aluminum plate that protects the IDE data conditioning and control electronics mounted underneath. The cover plate also serves as a mounting platform for ten (10) individual specimen holders provided by one of the IDE investigators.The material specimen, consisting of germanium, sapphire and zinc sulfide of different sizes, shapes and colors, are bonded to the specimen holders with an RTV adhesive. The specimen holders are attached to the cover plate with stainless steel non-magnetic fasteners. The 1/3rd tray cover plate in the right hand end of the experiment tray is an aluminum plate painted white with Chemglaze II A-276 paint and used as a thermal cover for the Experiment Power and Data System (EPDS). The EPDS is a system provided by the LDEF Project Office that processes and stores, on magnetic tape, the orbital experiment and housekeeping data from six (6) experiment locations on the LDEF.

1984-01-01

404

25-hydroxy vitamin D test  

MedlinePLUS

25-OH vitamin D test; Calcidiol; 25-hydroxycholecalciferol test ... if you have too much or too little vitamin D in your blood. ... than-normal levels can be due to a vitamin D deficiency, which can result from: Lack of ...

405

Multiple Sclerosis and Vitamin D  

MedlinePLUS

... vitamin D Andrew J. Solomon, MD WHAT IS VITAMIN D AND WHY IS IT IMPORTANT IN MS? ... e100 Neurology Andrew J. Solomon Multiple sclerosis and vitamin D This information is current as of October ...

406

Vitamin D and Disease Prevention  

MedlinePLUS

... The skin makes vitamin D after exposure to sunlight. We also absorb vitamin D from certain foods, ... not make enough vitamin D by exposure to sunlight* or get enough through their diets. They may ...

407

Vitamin Deficiencies and Your Mouth  

MedlinePLUS

... that might affect your mouth and teeth. Vitamin B Vitamin B deficiencies are one of the most common ... and may break apart easily and slough off. B-vitamin deficiencies also can lead to anemia (too few ...

408

Vitamin D and ageing  

Microsoft Academic Search

Within the past three to four decades a revolution has occurred in our understanding of vitamin D and its effects. Sundry\\u000a laboratory and epidemiologic studies have revealed that the active metabolite of vitamin D controls and\\/or ameliorates various\\u000a pathologies. As presented here, there is substantive evidence that vitamin D may play a positive and important role in the\\u000a ageing process.

Daniel P. Hayes

2010-01-01

409

[Vitamin D and autoimmunity].  

PubMed

Vitamin D acts at several levels in the immune systems to maintain immune tolerance. Vitamin D deficiency is a plausible environmental risk factor for autoimmune disease. Basic, genetic and epidemiological studies indicate a potential role of vitamin D in the prevention and the treatment of autoimmune diseases. Most of the epidemiological studies are cross-sectional, so that they are insufficient to establish a direct link between vitamin D deficiency and both disease risk and disease activity. Randomized, controlled trials are necessary. PMID:24051163

Schoindre, Yoland; Benveniste, Olivier; Costedoat-Chalumeau, Nathalie

2013-10-01

410

Vitamin D & endothelial function  

PubMed Central

There is increasing interest in the extra-skeletal roles of vitamin D for health and well-being. Poor vitamin D status has been associated with obesity, cardiovascular disease, type 2 diabetes and mental health. Endothelial dysfunction may underscore insulin resistance and hence predispose to both cardiovascular disease (CVD) and type 2 diabetes. The objective of this review was to gain an appreciation of the recent causative evidence linking vitamin D and endothelial function. The PubMed database was searched from 2009 to date. Key words used were vitamin D, supplementation, systemic inflammation, endothelium, endothelial dysfunction and humans. Selected articles were restricted to the English language and to randomized control trials (RCTs) of vitamin D supplementation with direct measures of endothelial function. Final inclusion was based on a quality rating ? 3, based on the Jadad score. Ten RCTs met these criteria and were summarized for their outcomes. Only two studies showed an improvement in flow mediated dilatation with vitamin D. Three other studies reported decreases in C-reactive protein, platelet activation inhibitor-1, tissue plasminogen activator or B type natriuretic peptide. Recent evidence from good quality RCTs did not support a beneficial effect of vitamin D on vascular reactivity. Future intervention studies may need to target a higher vitamin D status and longer duration to determine whether the vitamin has a regulatory role in endothelial function. PMID:25488441

Alyami, A.; Soares, M.J.; Sherriff, J.L.; Mamo, J.C.

2014-01-01

411

Vitamin D insufficiency and insulin resistance in obese adolescents.  

PubMed

Obese adolescents represent a particularly vulnerable group for vitamin D deficiency which appears to have negative consequences on insulin resistance and glucose homeostasis. Poor vitamin D status is also associated with future risk of type 2 diabetes and metabolic syndrome in the obese. The biological mechanisms by which vitamin D influences glycemic control in obesity are not well understood, but are thought to involve enhancement of peripheral/hepatic uptake of glucose, attenuation of inflammation and/or regulation of insulin synthesis/secretion by pancreatic ? cells. Related to the latter, recent data suggest that the active form of vitamin, 1,25-dihydroxyvitamin D, does not impact insulin release in healthy pancreatic islets; instead they require an environmental stressor such as inflammation or vitamin D deficiency to see an effect. To date, a number of observational studies exploring the relationship between the vitamin D status of obese adolescents and markers of glucose homeostasis have been published. Most, although not all, show significant associations between circulating 25-hydroxyvitamn D concentrations and insulin sensitivity/resistance indices. In interpreting the collective findings of these reports, significant considerations surface including the effects of pubertal status, vitamin D status, influence of parathyroid hormone status and the presence of nonalcoholic fatty liver disease. The few published clinical trials using vitamin D supplementation to improve insulin resistance and impaired glucose tolerance in obese adolescents have yielded beneficial effects. However, there is a need for more randomized controlled trials. Future investigations should involve larger sample sizes of obese adolescents with documented vitamin D deficiency, and careful selection of the dose, dosing regimen and achievement of target 25-hydroxyvitamn D serum concentrations. These trials should also include clamp-derived measures of in vivo sensitivity and ?-cell function to more fully characterize the effects of vitamin D replenishment on insulin resistance. PMID:25489472

Peterson, Catherine A; Tosh, Aneesh K; Belenchia, Anthony M

2014-12-01

412

17 CFR 270.8b-12 - Requirements as to paper, printing and language.  

Code of Federal Regulations, 2011 CFR

...Requirements as to paper, printing and language. 270.8b-12 Section 270.8b-12...Requirements as to paper, printing and language. (a) Registration statements and...statements and reports shall be in the English language. If any exhibit or other paper or...

2011-04-01

413

17 CFR 270.8b-12 - Requirements as to paper, printing and language.  

Code of Federal Regulations, 2010 CFR

...Requirements as to paper, printing and language. 270.8b-12 Section 270.8b-12...Requirements as to paper, printing and language. (a) Registration statements and...statements and reports shall be in the English language. If any exhibit or other paper or...

2010-04-01

414

Thiamin function, metabolism, uptake, and transport.  

PubMed

Vitamins are crucial components in the diet of animals and many other living organisms. One of these essential nutrients, thiamin, is known to be involved in several cell functions, including energy metabolism and the degradation of sugars and carbon skeletons. Other roles that are connected to this vitamin are neuronal communication, immune system activation, signaling and maintenance processes in cells and tissues, and cell-membrane dynamics. Because of the key functions of thiamin, uptake and transport through the body are crucial. Its uptake route is relatively complex, encompassing a variety of protein families, including the solute carrier anion transporters, the alkaline phosphatase transport system, and the human extraneuronal monoamine transporter family, some of which are multispecific proteins. There are two known structures of protein (subunits) involved in thiamin uptake in prokaryotes. Binding of thiamin to these proteins is strongly guided by electrostatic interactions. The lack of structural information about thiamin binding proteins for higher organisms remains a bottleneck for understanding the uptake process of thiamin in atomic detail. This review includes recent data on thiamin metabolism, related deficiencies and pathologies, and the latest findings on thiamin binding transporters. PMID:24460461

Manzetti, Sergio; Zhang, Jin; van der Spoel, David

2014-02-11

415

VITAMINS AND MINERALS  

NSDL National Science Digital Library

DESK Standard: Specify key vitamins and minerals and their functions. . DATES: You can begin this activity on May 21. You should complete it by May 25. OBJECTIVE: A healthy body needs vitamins and minerals. You\\'ve probably heard these words before, but do you really know what they mean? This activity will help you better understand the ...

Hughes, Mr.

2006-03-05

416

Vitamin C in Cuscuta  

Microsoft Academic Search

Zusammenfassung Die parasitierenden Stengel vonCuscuta Gronovii sind in den Partien in der Nähe der Haustorien chlorophyllfrei oder -arm und enthalten dort nur wenig Vitamin C, in weiterer Entfernung von den Haustorien sind die Stengelpartien dagegen relativ reich an Chlorophyll und Ascorbinsäure. Bei der Reifung derCuscuta- Samen nimmt der Vitamin-C-Gehalt ab.

Gertraud Walzel

1952-01-01

417

B Vitamins and Cognitive Performance in Older Adults: Review  

PubMed Central

A copious amount of scientific scrutiny has been dedicated to documenting typical and atypical human ageing, with a substantial body of work focusing upon the impact of lifestyle choices. One such lifestyle choice is that of diet and, in particular, micronutrient ingestion. Epidemiological studies have reported positive associations between B vitamin status and cognitive function, including negative associations between biological markers (i.e., homocysteine) of dysregulated one-carbon metabolism and cognitive function. This has led to a surge of randomised control trials (RCTs) investigations into B vitamin therapy. However, results have continuingly failed to show beneficial behavioural effects. Despite this, results reliably show treatment-related increases in B vitamin level and decreases in homocysteine level—both of which have been identified as risk factors for atypical ageing. In this paper we argue that it would be premature to conclude that B vitamin therapy has no potential and that more research is needed to systematically investigate the optimal dose, the therapeutic “window,” and individual differences in therapy responders and nonresponders. We start with a brief look at one-carbon metabolism and then consider the evidence from epidemiological studies and RCTs in relation to three specific B vitamins: folic acid (B9), pyridoxine (B6), and cobamides (B12). PMID:24959550

Reay, J. L.; Smith, M. A.; Riby, L. M.

2013-01-01

418

Evaluation of the vitamin status in nursing women by vitamin content in breast milk.  

PubMed

The dependence of daily vitamin excretion with breast milk on dietary vitamin content and blood vitamin level was studied in nursing women. Breast mils vitamins were assayed in women supplied with vitamins. We identified the criteria for adequate vitamin supply in nursing women over the 1st month after labor (vitamins A, 130 microg; vitamin B1, 100 microg; vitamin B2, 130 microg; vitamin E, 750 microg; vitamin B6, 60 microg). PMID:17073150

Kodentsova, V M; Vrzhesinskaya, O A

2006-03-01