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1

Starvation and Renal Uptake of Vitamin B12  

Microsoft Academic Search

Rosenthal and Cravitz have reported1-3 that rabbits subjected to starvation accumulated remarkably large amounts of vitamin B12 in the kidney as compared with normally fed controls. They also found similar, but less pronounced, effects of starvation in some animal species. No satisfactory explanation has been offered, however. Our investigations with rats demonstrated that the renal uptake of vitamin B12 labelled

Kunio Okuda

1962-01-01

2

Uptake of a microbially-produced vitamin (B12) by soybean roots  

Microsoft Academic Search

Vitamin B12 (Cyanocobalamin) is one of the vitamins believed to be produced exclusively by microorganisms. Although soil is a rich source of vitamin B12, systematic study as to possible uptake of this vitamin by the plant roots is lacking. This study was undertaken to investigate, under water culture conditions, the uptake of [57Co]-cyanocobalamin by soybean (Glycine max (L.) Merr.). In

A. Mozafar; J. J. Oertli

1992-01-01

3

Vitamin B 12 Transporters  

Microsoft Academic Search

The uptake of vitamin B12 from the intestine into the circulation is perhaps the most complex uptake mechanism of all the vitamins, involving no less\\u000a than five separate VB12-binding molecules, receptors and transporters. Each molecule involved in uptake has a separate affinity and specificity for\\u000a VB12 as well as a separate cell receptor. Thus VB12 is initially bound by haptocorrin

Gregory J. Russell-Jones; David H. Alpers

4

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.

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

2012-01-01

5

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

6

Vitamin B 12 Deficiency  

Microsoft Academic Search

Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia and the promotion of atherosclerosis is only now being explored. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with

ROBERT C. OH; DAVID L. BROWN

2003-01-01

7

Vitamin B12 level  

MedlinePLUS

... 200 pg/mL are a sign of a vitamin B12 deficiency. People with this deficiency are likely to have ... pg/mL may also have symptoms. Causes of vitamin B12 deficiency include: Not enough vitamin B12 in diet (rare ...

8

4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice.  

PubMed

Co?-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate the in vivo effect of EtPhCbl in mice and its ability, if any, to induce Cbl deficiency. We show that EtPhCbl binds to mouse TC and we examined mice that received 3.5 nmol/24h EtPhCbl (n=6), 3.5 nmol/24h CNCbl (n=7) or NaCl (control group) (n=5) through osmotic mini-pumps for four weeks. We analyzed plasma, urine, liver, spleen, submaxillary glands and spinal cord for Cbl and markers of Cbl deficiency including methylmalonic acid (MMA) and homocysteine (tHcy). Plasma MMA (mean±SEM) was elevated in animals treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups was analysed using one-way ANOVA and, Bonferroni post-hoc test. EtPhCbl was present in all tissues, except the spinal cord, accounting for 35-90% of total Cbl. In conclusion, treatment with EtPhCbl induces biochemical evidence of Cbl deficiency. This may in part be caused by a compromised tissue accumulation of Cbl. PMID:24073261

Mutti, Elena; Ruetz, Markus; Birn, Henrik; Kräutler, Bernhard; Nexo, Ebba

2013-09-20

9

4-Ethylphenyl-Cobalamin Impairs Tissue Uptake of Vitamin B12 and Causes Vitamin B12 Deficiency in Mice  

PubMed Central

Co?-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate the in vivo effect of EtPhCbl in mice and its ability, if any, to induce Cbl deficiency. We show that EtPhCbl binds to mouse TC and we examined mice that received 3.5 nmol/24h EtPhCbl (n=6), 3.5 nmol/24h CNCbl (n=7) or NaCl (control group) (n=5) through osmotic mini-pumps for four weeks. We analyzed plasma, urine, liver, spleen, submaxillary glands and spinal cord for Cbl and markers of Cbl deficiency including methylmalonic acid (MMA) and homocysteine (tHcy). Plasma MMA (mean±SEM) was elevated in animals treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups was analysed using one-way ANOVA and, Bonferroni post-hoc test. EtPhCbl was present in all tissues, except the spinal cord, accounting for 35-90% of total Cbl. In conclusion, treatment with EtPhCbl induces biochemical evidence of Cbl deficiency. This may in part be caused by a compromised tissue accumulation of Cbl.

Mutti, Elena; Ruetz, Markus; Birn, Henrik; Krautler, Bernhard; Nexo, Ebba

2013-01-01

10

Vitamin B12 transporters.  

PubMed

The uptake of vitamin B12 from the intestine into the circulation is perhaps the most complex uptake mechanism of all the vitamins, involving no less than five separate VB12-binding molecules, receptors and transporters. Each molecule involved in uptake has a separate affinity and specificity for VB12 as well as a separate cell receptor. Thus VB12 is initially bound by haptocorrin in the stomach, then by IF in the small intestine. An IF receptor is then involved in uptake of the IF-VB12 complex by the intestinal epithelial cell, with the subsequent proteolytic release of VB12 and subsequent binding to TcII. The TcII receptor then transports the TcII-VB12 complex across the cell, whence it is released into the circulation. It is surprising, then, that despite its complexity, it has been possible to harness the vitamin VB12 uptake mechanism to enhance the oral uptake of peptides, proteins, and nanoparticles. PMID:10742986

Russell-Jones, G J; Alpers, D H

1999-01-01

11

VITAMIN B-12  

Technology Transfer Automated Retrieval System (TEKTRAN)

Because vitamin B-12 is only found in animal source foods, strict vegetarianism has long been associated with a greater risk of deficiency of this vitamin. The elderly, many of whom lose their ability to absorb vitamin B-12, and the small proportion of the population with pernicious anemia due to la...

12

The effect of recombinant human intrinsic factor on the uptake of vitamin B12 in patients with evident vitamin B12 deficiency.  

PubMed

We report on the use of recombinant human intrinsic factor (rhIF) in a new vitamin B12 absorption test. Holotranscobalamin (holoTC) was measured before and 24 hours after intake of three 9-mg doses of vitamin B12 (B12) and again 24 hours after intake of the same dose of B12 together with rhIF (rhIF-B12). Nine patients with evident vitamin B12 deficiency had a significantly higher increase in holoTC after intake of rhIF-B12 than after intake of B12. Twenty-eight patients with suspected vitamin B12 deficiency showed no additional increase in holoTC after intake of rhIF-B12. We conclude that rhIF promotes B12 absorption among patients with evident vitamin B12 deficiency. PMID:16704961

Hvas, Anne-Mette; Buhl, Hora; Laursen, Niels Bech; Hesse, Birger; Berglund, Lars; Nexo, Ebba

2006-05-16

13

Selective Uptake of Specifically Bound Cobalt58 Vitamin B12 by Human and Mouse Tumour Cells  

Microsoft Academic Search

MANY body fluids have been reported to contain substances that combine with vitamin B12. However, research concerning the role of these substances in the absorption of vitamin B12 by animal cells has been confined mainly to work involving intrinsic factor preparations or normal human gastric juice. A large amount of evidence has led to general acceptance that vitamin B12 bound

Bernard A. Cooper; William Paranchych

1961-01-01

14

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 ...

15

Absent ileal uptake of IF-bound vitamin B12 in vivo in the Imerslund-Grasbeck syndrome (familial vitamin B12 malabsorption with proteinuria)  

Microsoft Academic Search

A Syrian family is described with three children who had inherited selective vitamin B12 malabsorption associated with proteinuria. (Imerslund-Grasbeck syndrome). Although inherited the defect was apparently not present at birth. A third child had less severe vitamin B12 malabsorption, was not vitamin B12 deficient and had no proteinuria. Studies on two of the affected children with subcellular fractionation of the

J F Burman; W J Jenkins; J A Walker-Smith; A D Phillips; N A Sourial; C B Williams; D L Mollin

1985-01-01

16

Transcobalamin II-mediated uptake of vitamin B12 by rat liver cells  

Microsoft Academic Search

Vitamin B12 plays a unique role in mammalian metabolism\\u000anot only because, as a coenzyme, it is involved in two\\u000acompletely different and unrelated biochemical pathways, -\\u000athe synthesis of nucleic acid precursors and the catabolism\\u000aof some fatty acids -, but even more because it gives an\\u000aexcellent example how different groups of living organisms\\u000awork together and depend

J. Lindemans

1979-01-01

17

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...

18

Vitamin B12  

MedlinePLUS

... form works as well. The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin ... people should receive on a daily basis. The RDA for vitamins may be used as goals for ...

19

Improved vitamin B 12 production by step-wise reduction of oxygen uptake rate under dissolved oxygen limiting level during fermentation process  

Microsoft Academic Search

Effects of different oxygen transfer rates (OTR) on the cell growth and vitamin B12 biosynthesis of Pseudomonas denitrificans were first investigated under dissolved oxygen limiting conditions. The results demonstrated that high OTR accelerated cell growth and initial vitamin B12 biosynthesis rate, while lower OTR was critical for higher productivity in the late fermentation process. The oxygen uptake rates (OUR) corresponded

Ze-Jian Wang; Hui-Yuan Wang; Yong-Liang Li; Ju Chu; Ming-Zhi Huang; Ying-Ping Zhuang; Si-Liang Zhang

2010-01-01

20

Functional vitamin B12 deficiency  

Microsoft Academic Search

We describe a case of functional vitamin B12 deficiency where the repeated measurement of a serum B12 level within the normal range led to delay in the diagnosis of subacute combined degeneration of the spinal cord, and possibly permanent neurological damage as a result. Failure of intracellular transport of B12 by transcobalamin-2 can lead to functional B12 deficiency but with

M R Turner; K Talbot

2009-01-01

21

Vitamin B12: chemical modifications.  

PubMed

Vitamin B12 plays a key role in many metabolic processes occurring in all mammals. Over the years its biological role has been extensively studied generating a lot of interest in the chemistry of this vital molecule. This established a variety of new methodologies for the synthesis and analysis of new cobalamin derivatives as well as creative purification techniques. This tutorial review summarizes all the advancements made in this area, providing a deeper insight into vitamin B12 chemistry. PMID:23715409

ó Proinsias, Keith; Giedyk, Maciej; Gryko, Dorota

2013-05-29

22

Bioavailability of vitamin B12  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied t...

23

Bioavailability of vitamin B12.  

PubMed

Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied to diagnose vitamin B12 malabsorption, including Schilling?s test, which is now used rarely, but these do not quantify percent bioavailability. Most of the information on B12 bioavailability from foods was collected 40 to 50 years ago, using radioactive isotopes of cobalt to label the corrinoid ring. The data are sparse, and the level of radioactivity required for in vivo labeling of animal tissues can be prohibitive. A newer method under development uses a low dose of radioactivity as (14)C-labeled B12, with measurement of the isotope excreted in urine and feces by accelerator mass spectrometry. This test has revealed that the unabsorbed vitamin is degraded in the intestine. The percent bioavailability is inversely proportional to the dose consumed due to saturation of the active absorption process, even within the range of usual intake from foods. This has important implications for the assessment and interpretation of bioavailability values, setting dietary requirements, and interpreting relationships between intake and status of the vitamin. PMID:21462117

Allen, Lindsay Helen

2010-10-01

24

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.

25

ABC transporter-mediated uptake of iron, siderophores, heme and vitamin B 12  

Microsoft Academic Search

Microbes have developed a number of different strategies to utilize iron, which is a vital element for most organisms but not always readily available from the environment. Based on experimental studies and sequence analysis data, this article gives a short overview of ABC transporters related to iron uptake: components of three distinct families mediate the translocation of iron, siderophores, heme

Wolfgang Köster

2001-01-01

26

Vitamin B12 Sources and Bioavailability  

Microsoft Academic Search

The usual dietary sources of vitamin B12 are animal foods, meat, milk, egg, fish, and shellfish. As the intrinsic factor-mediated intestinal absorption system is estimated to be saturated at about 1.5-2.0 lg per meal under physiologic conditions, vitamin B12 bioavailability significantly decreases with increasing intake of vitamin B12 per meal. The bioavailability of vitamin B12 in healthy humans from fish

FUMIO WATANABE

2007-01-01

27

"Clickable" vitamin B12 derivative.  

PubMed

A "clickable" vitamin B12 derivative possessing the azide functionality at the 5'-position was synthesized by means of a two-step procedure on the gram scale. The reaction of cobalamin with mesyl chloride (MsCl) afforded the 5'-OMs derivative, which was subsequently transformed to the desired 5'-azide, the structure of which was confirmed using X-ray analysis. It proved to be reactive in the azide-alkyne 1,3-dipolar cycloaddition reaction to give substituted triazoles in high yields. A study of the reaction conditions and the scope of the process are reported. PMID:23325459

Chromi?ski, Miko?aj; Gryko, Dorota

2013-01-16

28

Vitamin B12 sources and bioavailability.  

PubMed

The usual dietary sources of vitamin B(12) are animal foods, meat, milk, egg, fish, and shellfish. As the intrinsic factor-mediated intestinal absorption system is estimated to be saturated at about 1.5-2.0 microg per meal under physiologic conditions, vitamin B(12) bioavailability significantly decreases with increasing intake of vitamin B(12) per meal. The bioavailability of vitamin B(12) in healthy humans from fish meat, sheep meat, and chicken meat averaged 42%, 56%-89%, and 61%-66%, respectively. Vitamin B(12) in eggs seems to be poorly absorbed (< 9%) relative to other animal food products. In the Dietary Reference Intakes in the United States and Japan, it is assumed that 50% of dietary vitamin B(12) is absorbed by healthy adults with normal gastro-intestinal function. Some plant foods, dried green and purple lavers (nori) contain substantial amounts of vitamin B(12), although other edible algae contained none or only traces of vitamin B(12). Most of the edible blue-green algae (cyanobacteria) used for human supplements predominantly contain pseudovitamin B(12), which is inactive in humans. The edible cyanobacteria are not suitable for use as vitamin B(12) sources, especially in vegans. Fortified breakfast cereals are a particularly valuable source of vitamin B(12) for vegans and elderly people. Production of some vitamin B(12)-enriched vegetables is also being devised. PMID:17959839

Watanabe, Fumio

2007-11-01

29

Oral delivery of the appetite suppressing peptide hPYY(3-36) through the vitamin B12 uptake pathway.  

PubMed

hPYY(3-36) injections have shown positive effects on appetite regulations, sparking increased interest in hPYY(3-36) research. Of great interest is oral delivery of hPYY(3-36) that can achieve clinically relevant weight-loss outcomes in what would be a highly patient compliant route. Successful oral delivery of other peptides utilizing the vitamin B12 pathway has been shown but below clinically relevant levels. Herein, we present clinically relevant in vivo oral delivery of B12-hPYY(3-36) conjugates. PMID:22054008

Fazen, Christopher H; Valentin, Debbie; Fairchild, Timothy J; Doyle, Robert P

2011-11-16

30

Vitamin B12 in health and disease.  

PubMed

Vitamin B(12) is essential for DNA synthesis and for cellular energy production.This review aims to outline the metabolism of vitamin B(12), and to evaluate the causes and consequences of sub-clinical vitamin B(12) deficiency. Vitamin B(12) deficiency is common, mainly due to limited dietary intake of animal foods or malabsorption of the vitamin. Vegetarians are at risk of vitamin B(12) deficiency as are other groups with low intakes of animal foods or those with restrictive dietary patterns. Malabsorption of vitamin B(12) is most commonly seen in the elderly, secondary to gastric achlorhydria. The symptoms of sub-clinical deficiency are subtle and often not recognized. The long-term consequences of sub-clinical deficiency are not fully known but may include adverse effects on pregnancy outcomes, vascular, cognitive, bone and eye health. PMID:22254022

O'Leary, Fiona; Samman, Samir

2010-03-05

31

Update on vitamin B12 deficiency.  

PubMed

Vitamin B(12) (cobalamin) deficiency is a common cause of megaloblastic anemia, a variety of neuropsychiatric symptoms, and elevated serum homocysteine levels, especially in older persons. There are a number of risk factors for vitamin B(12) deficiency, including prolonged use of metformin and proton pump inhibitors. No major medical organizations, including the U.S. Preventive Services Task Force, have published guidelines on screening asymptomatic or low-risk adults for vitamin B(12) deficiency, but high-risk patients, such as those with malabsorptive disorders, may warrant screening. The initial laboratory assessment of a patient with suspected vitamin B(12) deficiency should include a complete blood count and a serum vitamin B(12) level. Measurements of serum vitamin B(12) may not reliably detect deficiency, and measurement of serum homocysteine and/or methylmalonic acid should be used to confirm deficiency in asymptomatic high-risk patients with low normal levels of vitamin B(12). Oral administration of high-dose vitamin B(12) (1 to 2 mg daily) is as effective as intramuscular administration in correcting the deficiency, regardless of etiology. Because crystalline formulations are better absorbed than naturally occurring vitamin B(12), patients older than 50 years and strict vegetarians should consume foods fortified with vitamin B(12) and vitamin B(12) supplements, rather than attempting to get vitamin B(12) strictly from dietary sources. Administration of vitamin B(12) to patients with elevated serum homocysteine levels has not been shown to reduce cardiovascular outcomes in high-risk patients or alter the cognitive decline of patients with mild to moderate Alzheimer disease. PMID:21671542

Langan, Robert C; Zawistoski, Kimberly J

2011-06-15

32

Malabsorption of protein bound vitamin B12.  

PubMed Central

Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, or folate deficiency. Defective absorption was also found in six patients with an adequate dietary intake of vitamin B12, normal Schilling test results, low serum vitamin concentrations, and tissue changes responding to treatment with vitamin B12. Malabsorption of the vitamin from protein bound sources, which is not detected by the Schilling test, may produce vitamin B12 deficiency of clinical importance.

Dawson, D W; Sawers, A H; Sharma, R K

1984-01-01

33

Malabsorption of protein bound vitamin B12  

Microsoft Academic Search

Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences

D W Dawson; A H Sawers; R K Sharma

1984-01-01

34

[Approaches to vitamin B12 deficiency].  

PubMed

A 28-year-old female vegetarian was referred to a specialist in internal medicine with persistent iron deficiency. Laboratory analysis revealed microcytic anaemia with low ferritin levels but normal total vitamin B12 levels. The red blood cell distribution width, however, showed a very wide variation in red blood cell sizes, indicating a coexisting vitamin B12 deficiency, which was confirmed by the low concentration of active vitamin B12. Another patient, a 69-year-old woman with a history of previous gastric surgery and renal insufficiency as a complication of diabetes mellitus, was suspected to be deficient in vitamin B12, as she had low total vitamin B12 levels and an accumulation of methylmalonic acid and homocysteine in her blood. Testing the total concentration of vitamin B12 alone has insufficient diagnostic accuracy and no accepted gold standard is available for diagnosing vitamin B12 deficiency. With the development of newer tests, such as measuring holotranscobalamin II (concentration of active vitamin B12), atypical and subclinical deficiency states can be recognized. A new approach to diagnosing vitamin B12 deficiency is presented, based upon these 2 case descriptions. PMID:22217304

Russcher, Henk; Heil, Sandra G; Slobbe, Lennert; Lindemans, Jan

2012-01-01

35

Oral or intramuscular vitamin B12?  

PubMed

Vitamin B(12) deficiency is common, becoming more so with age, and estimates of its population prevalence have ranged from 1.5% to 15%. If untreated, it can lead to megaloblastic anaemia and irreversible neurological complications. In the UK, the usual treatment is regular intramuscular injections of hydroxocobalamin. High-dose oral vitamin B(12) replacement is standard practice in some other countries and less costly. Here we review issues around adopting an oral vitamin B(12) replacement regimen more widely in the UK. PMID:19193702

2009-02-01

36

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

37

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials  

Microsoft Academic Search

Objectives. We set out to identify randomized controlled trial (RCT) evidence for the effectiveness of oral versus intramuscular vitamin B12 to treat vitamin B12 deficiency. Methods. We conducted a systematic review searching databases for relevant RCTs. Outcomes included levels of serum vitamin B12, total serum homocysteine and methylmalonic acid, haemoglobin and signs and symptoms of vitamin B12 deficiency. Results. Two

Christopher C Butler; Josep Vidal-Alaball; Rebecca Cannings-John; Andrew McCaddon; Kerenza Hood; Alexandra Papaioannou; Ian Mcdowell; Andrew Goringe

2006-01-01

38

21 CFR 582.5945 - Vitamin B12.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 false Vitamin B12. 582.5945 Section 582...HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED...Supplements 1 § 582.5945 Vitamin B12. (a) Product. Vitamin B12 . (b) Conditions of...

2009-04-01

39

A vitamin B12 transporter in Mycobacterium tuberculosis  

PubMed Central

Vitamin B12-dependent enzymes function in core biochemical pathways in Mycobacterium tuberculosis, an obligate pathogen whose metabolism in vivo is poorly understood. Although M. tuberculosis can access vitamin B12 in vitro, it is uncertain whether the organism is able to scavenge B12 during host infection. This question is crucial to predictions of metabolic function, but its resolution is complicated by the absence in the M. tuberculosis genome of a direct homologue of BtuFCD, the only bacterial B12 transport system described to date. We applied genome-wide transposon mutagenesis to identify M. tuberculosis mutants defective in their ability to use exogenous B12. A small proportion of these mapped to Rv1314c, identifying the putative PduO-type ATP : co(I)rrinoid adenosyltransferase as essential for B12 assimilation. Most notably, however, insertions in Rv1819c dominated the mutant pool, revealing an unexpected function in B12 acquisition for an ATP-binding cassette (ABC)-type protein previously investigated as the mycobacterial BacA homologue. Moreover, targeted deletion of Rv1819c eliminated the ability of M. tuberculosis to transport B12 and related corrinoids in vitro. Our results establish an alternative to the canonical BtuCD-type system for B12 uptake in M. tuberculosis, and elucidate a role in B12 metabolism for an ABC protein implicated in chronic mycobacterial infection.

Gopinath, Krishnamoorthy; Venclovas, Ceslovas; Ioerger, Thomas R.; Sacchettini, James C.; McKinney, John D.; Mizrahi, Valerie; Warner, Digby F.

2013-01-01

40

Vitamin B12 and geriatrics: unanswered questions.  

PubMed

Vitamin B12 is an important area in the interface between geriatrics and hematology. B12 deficiency is more common in the elderly and because its neurologic manifestations overlap very common disorders such as dementia, the diagnosis may be more subtle in the elderly. The critical question is whether early treatment of B12 deficiency can prevent some cases of dementia. If prevention is possible, then all elderly patients should be screened for cobalamin deficiency. Research must be ongoing to determine the most cost-effective strategy for evaluating low B12 levels. In our view careful review of the blood smear is still very useful. Although requiring further study, the Herbert/Herzlich model should prove to be very useful to the clinician evaluating patients for possible B12 deficiency. Finally, although the treatment is lifelong, we would argue that when in doubt the patient should be treated. The cost of therapy is small when balanced against the potential consequences. PMID:2511717

Thompson, W G; Freedman, M L

1989-01-01

41

[Folate, vitamin B12 and human health].  

PubMed

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poor folate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health. PMID:23677195

Brito, Alex; Hertrampf, Eva; Olivares, Manuel; Gaitán, Diego; Sánchez, Hugo; Allen, Lindsay H; Uauy, Ricardo

2012-11-01

42

Folate, vitamin B12 and human health  

Technology Transfer Automated Retrieval System (TEKTRAN)

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared func...

43

MRI in Vitamin B12 Deficiency Myelopathy  

Microsoft Academic Search

Background: Little is known about vitamin B 12 deficiency myelopathy's magnetic reso- nance imaging (MRI) manifestations and their relationship to the onset, evolution, and resolution of neuro - logic signs and symptoms. Methods: We present a case and review eleven additional reported cases of subacute combined degeneration of the spinal cord detected by MRI. Results: Our patient had increased T2-weighted

Eduardo R. Locatelli; Robert Laureno; Pamela Ballard; Alexander S. Mark

44

to the Radioassayof VitaminB12  

Microsoft Academic Search

Cobalt-57 can be measured in a liquid scintillation counting system. We describe the calibration of such a system for this gamma emitter. The counting pro- cedure has been used in the radioassay of vitamin B12. Results of assays for which counting of bound radioisotope was done in a gamma scintillation spec- trometer and in a liquid scintillation counter show that

James Johnson; Henry McCarter

45

Nutritional vitamin-B12 deficiency. Possible contributory role of subtle vitamin-B12 malabsorption.  

PubMed

Dietary deficiency of vitamin B-12 has been reported, yet most people ingesting vitamin-B12-deficient diets even for many years appear to achieve a balance that does not lead to overt signs and symptoms of deficiency. I present the case of a vegan of 25 years' duration who developed severe neurologic abnormalities due to vitamin-B12 deficiency. His diet provided 1.2 microgram of vitamin B12 daily at most. Despite normal Schilling test findings, he absorbed subnormal amounts of vitamin B12 given with ovalbumin. This poor absorption appeared to be related to his gastritis, achlorhydria, and subnormal intrinsic-factor secretion. Probably, vitamin-B12 deficiency in this patient resulted from both dietary restriction and the subtle malabsorption, neither of which would have sufficed alone to produce the clinical problem. Possibly such malabsorption may also be present in many of those vegans developing overt vitamin-B12 deficiency in whom Schilling test findings have been normal. PMID:646250

Carmel, R

1978-05-01

46

The effect of increasing the Vitamin B12 status of Romney ewes on foetal liver Vitamin B12, milk Vitamin B12 and liver Vitamin B12 concentrations in suckling lambs  

Microsoft Academic Search

Aim. To determine the effect of increasing the Vitamin B12 status of the ewe on the Vitamin B12 supply to the suckling lamb.Methods. The Vitamin B12 status of the ewe was increased during gestation and lactation by three injections of a long- acting preparation of Vitamin B12 microencapsulated in an organic acid polymer. The Vitamin B12 status of the ewes

N. D. Grace

1999-01-01

47

Production of Vitamin B12 and Vitamin B12 Analogues by Pure Cultures of Ruminal Bacteria  

Microsoft Academic Search

MICROBIAL fermentation in the rumen was early recognized as the primary source of vitamin B12 for the cow1. Rumen contents contain not only the vitamin itself but also certain analogues in which the nucleotide portion of the vitamin is missing or modified by the substitution of a different benzimidazole or a purine for the base (5 : 6-dimethylbenzimidazole). In general,

L. P. Dryden; A. M. Hartman; M. P. Bryant; I. M. Robinson; L. A. Moore

1962-01-01

48

Orthostatic tolerance in older patients with vitamin B12 deficiency before and after vitamin B12 replacement  

Microsoft Academic Search

Orthostatic hypotension (OH) and vitamin B12 deficiency are common disorders in older people. Several case series have reported an association between vitamin B12 deficiency and OH. The effect of vitamin B12 replacement on this dysfunction has not been studied. We prospectively studied responses to head up tilt in patients over 70 years with vitamin B12 deficiency (intervention group) and compared

Allan Moore; Jude Ryan; Michael Watts; Isweri Pillay; David Clinch; Declan Lyons

2004-01-01

49

Detection of Vitamin B12 Deficiency in Older People by Measuring Vitamin B12 or the Active Fraction of Vitamin B12, Holotranscobalamin  

Microsoft Academic Search

Background: Impaired vitamin B12 function and de- creased vitamin B12 status have been associated with neurological and cognitive impairment. Current assays analyze total vitamin B12 concentration, only a small percentage of which is metabolically active. Concentra- tions of this active component, carried on holotransco- balamin (holoTC), may be of greater relevance than total vitamin B12. Methods: We compared the utility

Robert Clarke; Paul Sherliker; Harold Hin; Ebba Nexo; Anne Mette Hvas; Joern Schneede; Jacqueline Birks; Per M. Ueland; Kathleen Emmens; John M. Scott; Anne M. Molloy; John Grimley Evans

2007-01-01

50

Effect of vitamin B12-enriched thraustochytrids on the population growth of rotifers.  

PubMed

Newly isolated thraustochytrids showed uptake of vitamin B12 from the culture into the cells. Cultivation of thraustochytrids in a medium containing 1 microg/ml of vitamin B12 greatly increased the contents of vitamin B12 in the cells. Similarly to Schizochytrium limacinum, odd numbered fatty acids decreased in the cells of new isolates cultivated with vitamin B12. Vitamin B12-enriched thraustochytrids, strain mh0186, enhanced the population growth of rotifers fed on the cells as sole feed. PMID:17213643

Hayashi, Masahiro; Yukino, Tsugiyo; Watanabe, Fumio; Miyamoto, Emi; Nakano, Yoshihisa

2007-01-07

51

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.

Delva, M. D.

1997-01-01

52

Clinically significant vitamin B 12 deficiency secondary to malabsorption of protein-bound vitamin B 12  

Microsoft Academic Search

Protein- (chicken serum) bound [57Co]cyanocobalamin absorption was evaluated in five hypochlorhydric patients who had developed B12 deficiency despite having normal absorption of unbound crystalline vitamin B12. All five patients had decreased urinary excretion of protein-bound B12 (0.06–0.34%) as compared to twelve normal controls (0.61–5.6%), P12 absorption in four of the five patients occurred with the exogenous administration of hydrochloric acid,

Charles E. King; John Leibach; Phillip P. Toskes

1979-01-01

53

Assay for Vitamin B12 Absorption and Method of Making Labeled Vitamin B12.  

National Technical Information Service (NTIS)

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

J. Miller P. J. Anderson R. Green S. Dueker

2005-01-01

54

Vitamin B 12 and marine ecology  

Microsoft Academic Search

Kurzfassung Der Einsatz von Turbidostaten und Chemostaten zur Dauerkultur von Algen kann auch einer Analyse der Kinetik von Prozessen dienen, die durch die Konzentration bestimmter Nähr- und Wirkstoffe limitiert werden. Die Parameter des Vitamin-B12-Bedarfs vonSkeletonema costatum wurden im Kulturversuch nach dem Chemostat-Prinzip bestimmt und mit denen vonMonochrysis lutheri verglichen; sie stimmen bei beiden Arten weitgehend überein. Es ließ sich zeigen,

M. R. Droop

1970-01-01

55

Vitamin B 12 and brain development  

Microsoft Academic Search

This is a report of a 11\\/2-year-old male with megaloblastic anaemia and a progressive neurological disorder clinically resembling\\u000a leucodystrophy. The child was exclusively breast fed and his mother had been a strict vegetarian for more than 4 years before\\u000a the child was born. After Vitamin B12 therapy the anaemia disappeared and the neurological condition dramatically improved.

K. Stollhoff; F. J. Schulte

1987-01-01

56

[Vitamin B12 and transcobalamin in chronic myeloproliferative disorders].  

PubMed

Although vitamin B12 is an essential coenzyme for DNA synthesis, humans, like other mammals, are incapable of synthesizing it. The role of intrinsic factor (IF) in B12 absorption is widely known, but, in fact there exists a much more intricate and complex mechanism for the effective assimilation of this important trace element in humans. B12 binding proteins play important roles in all stages of vitamin B12 metabolism. They are involved not only in its absorption, but also in its transport in serum, uptake to cells, storage in organs, enterohepatic circulation, and elimination of its analogues. Besides IF, well-known as a vitamin B12 binding protein found in gastric juice, there are other kinds of binding proteins found in human serum which are composed to transcobalamin (TC) I, II and III. Elevation of the vitamin B12 level in chronic myelogenous leukemia was first reported in the 1950s. Since then, B12 elevation has been found to occur in other kinds of chronic myeloproliferative disorders (CMPDs) as well and to be caused by an increase of serum TC. In CMPDs, either TCI or TCIII increases, but, the degree of elevation and the type of TC involved differs for each disorder. This article describes the changes in TC of CMPD patients. With the induction of the developed radioimmunoassay for R-type B12 binding protein, many cases have been examined. In addition, detailed qualitative analysis using DEAE cellulose column chromatography has been included for conditions not previously reported.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8295340

Iseki, T

1993-12-01

57

The Soluble Receptor for Vitamin B12 Uptake (sCD320) Increases during Pregnancy and Occurs in Higher Concentration in Urine than in Serum  

PubMed Central

Background Cellular uptake of vitamin B12 (B12) demands binding of the vitamin to transcobalamin (TC) and recognition of TC-B12 (holoTC) by the receptor CD320, a receptor expressed in high quantities on human placenta. We have identified a soluble form of CD320 (sCD320) in serum and here we present data on the occurrence of this soluble receptor in both serum and urine during pregnancy. Methods We examined serum from twenty-seven pregnant women (cohort 1) at gestational weeks 13, 24 and 36 and serum and urine samples from forty pregnant women (cohort 2) tested up to 8 times during gestational weeks 17-41. sCD320, holoTC, total TC and complex formation between holoTC and sCD320 were measured by in-house ELISA methods, while creatinine was measured on the automatic platform Cobas 6000. Size exclusion chromatography was performed on a Superdex 200 column. Results Median (range) of serum sCD320 increased from 125 (87-839) pmol/L (week 15) to reach a peak value of 199 (72-672) pmol/L (week 35) then dropped back to its baseline level just before birth (week 40). Around one third of sCD320 was precipitated with holoTC at all-time points studied. The urinary concentration of sCD320 was around two fold higher than in serum. Urinary sCD320/creatinine ratio correlated with serum sCD320 and reached a peak median level of 53 (30–101) pmol/mmol creatinine (week 35). sCD320 present in serum and urine showed the same elution pattern upon size exclusion chromatography. Conclusion We report for the first time that sCD320 is present in urine and in a higher concentration than in serum and that serum and urine sCD320 increase during pregnancy. The high urinary concentration and the strong correlation between urinary and serum sCD320 suggests that sCD320 is filtered in the kidney.

Abuyaman, Omar; Andreasen, Birgitte H.; Kronborg, Camilla; Vittinghus, Erik; Nexo, Ebba

2013-01-01

58

The anaerobic biosynthesis of vitamin B12.  

PubMed

Vitamin B12 (cobalamin) is a cobalt-containing modified tetrapyrrole that is an essential nutrient for higher animals. Its biosynthesis is restricted to certain bacteria and requires approximately 30 enzymatic steps for its complete de novo construction. Remarkably, two distinct biosynthetic pathways exist, which are termed the aerobic and anaerobic routes. The anaerobic pathway has yet to be fully characterized due to the inherent instability of its oxygen-sensitive intermediates. Bacillus megaterium, a bacterium previously used for the commercial production of cobalamin, has a complete anaerobic pathway and this organism is now being used to investigate the anaerobic B12 pathway through the application of recent advances in recombinant protein production. The present paper provides a summary of recent findings in the anaerobic pathway and future perspectives. PMID:22616870

Moore, Simon J; Warren, Martin J

2012-06-01

59

MRI of the Spinal Cord in Vitamin B12 Deficiency  

Microsoft Academic Search

Vitamin B12 deficiency causes hematological and neurological diseases. Subacute combined degeneration (SCD) of the spinal cord characterized by degeneration of the lateral and posterior columns is often found due to vitamin B 12 deficiency. We described three patients with SCD presenting with cervical and thoracic myelopathy. Laboratory data revealed vitamin B 12 deficiency and MRI of the spinal cord demonstrated

Chin-Hua Fu; Hui-Ching Chen; Wen-Long Tsao

60

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

61

21 CFR 184.1945 - Vitamin B12.  

Code of Federal Regulations, 2010 CFR

... 3 2009-04-01 2009-04-01 false 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 H88...

2009-04-01

62

21 CFR 184.1945 - Vitamin B12.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 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 H88...

2010-01-01

63

Experiences with dual protein bound aqueous vitamin B12 absorption test in subjects with low serum vitamin B12 concentrations  

Microsoft Academic Search

A dual isotope vitamin B12 absorption test in which vitamin B12 is given both in aqueous solution and bound to protein (chicken serum), was evaluated in 26 controls and 68 patients with subnormal serum vitamin B12 concentrations (19 with pernicious anaemia, 13 with iron deficiency, seven after partial gastrectomy, seven with malabsorptive states, five with folate deficiency, four with chronic

D I Gozzard; D W Dawson; M J Lewis

1987-01-01

64

Neuro-regression in vitamin B12 deficiency  

PubMed Central

Neuroregression in infants has varied aetiology and vitamin B12 deficiency is one of the uncommon causes. Infantile vitamin B12 deficiency is encountered in malnourished infants or in offspring of strict vegan mothers. We present two cases, both infants of 10 and 8 months of age, whose mothers had vitamin B12 deficiency. On admission, the patients were apathic, hypotonic and lethargic. Serum vitamin B12 levels were below normal limits. On cranial MRI, T2-weighted images revealed frontoparietal cortical atrophy. Both the infants responded to vitamin B12 treatment.

Agrawal, Sanwar; Nathani, Shweta

2009-01-01

65

Normalization of plasma vitamin B12 concentration by intranasal hydroxocobalamin in vitamin B12-deficient patients  

Microsoft Academic Search

BACKGROUND & AIMS: Patients with previous stomach and terminal ileum resections are often treated with intramuscular vitamin B12 injections. Disadvantages are, on a worldwide scale, the frequent need for medical personnel to administer injections and the sometimes painful way of application. This study was designed to investigate the feasibility of intranasal hydroxocobalamin suppletion in cobalamin-deficient patients and to assess whether

W. Bruins Slot; F. W. H. M. Merkus; SJ Van Deventer; G. N. J. Tytgat

1997-01-01

66

Serum Vitamin B12 and Blood Cell Values in Vegetarians  

Microsoft Academic Search

Serum vitamin B12 and complete blood count values were determined for 83 volunteer subjects from an American vegetarian society conference (USA). Among subjects who did not supplement their diets with vitamin B12 or multiple vitamin tablets, 92% of the vegans (total vegetarians), 64% of the lactovegetarians, 47% of the lacto-ovovegetarians and 20% of the semivegetarians had serum vitamin B12 levels

Allen Dong; Stephen C. Scott

1982-01-01

67

Genetic Variation in Vitamin B-12 Content of Bovine Milk and Its Association with SNP along the Bovine Genome  

PubMed Central

Vitamin B-12 (also called cobalamin) is essential for human health and current intake levels of vitamin B-12 are considered to be too low. Natural enrichment of the vitamin B-12 content in milk, an important dietary source of vitamin B-12, may help to increase vitamin B-12 intake. Natural enrichment of the milk vitamin B-12 content could be achieved through genetic selection, provided there is genetic variation between cows with respect to the vitamin B-12 content in their milk. A substantial amount of genetic variation in vitamin B-12 content was detected among raw milk samples of 544 first-lactation Dutch Holstein Friesian cows. The presence of genetic variation between animals in vitamin B-12 content in milk indicates that the genotype of the cow affects the amount of vitamin B-12 that ends up in her milk and, consequently, that the average milk vitamin B-12 content of the cow population can be increased by genetic selection. A genome-wide association study revealed significant association between 68 SNP and vitamin B-12 content in raw milk of 487 first-lactation Dutch Holstein Friesian cows. This knowledge facilitates genetic selection for milk vitamin B-12 content. It also contributes to the understanding of the biological mechanism responsible for the observed genetic variation in vitamin B-12 content in milk. None of the 68 significantly associated SNP were in or near known candidate genes involved in transport of vitamin B-12 through the gastrointestinal tract, uptake by ileum epithelial cells, export from ileal cells, transport through the blood, uptake from the blood, intracellular processing, or reabsorption by the kidneys. Probably, associations relate to genes involved in alternative pathways of well-studied processes or to genes involved in less well-studied processes such as ruminal production of vitamin B-12 or secretion of vitamin B-12 by the mammary gland.

Rutten, Marc J. M.; Bouwman, Aniek C.; Sprong, R. Corinne; van Arendonk, Johan A. M.; Visker, Marleen H. P. W.

2013-01-01

68

Vitamin B12 Activity in the Serum of the Rat  

Microsoft Academic Search

A STUDY is being made in this Department on the metabolism of vitamin B12 in the albino rat, and on the effects of deficiency of this vitamin produced by dietary and other means. As part of this study, the possibility was investigated of using microbiological assays of vitamin B12 activity in serum to assess the nutritional state of the animals

G. H. Spray; K. B. Taylor

1958-01-01

69

The pathophysiology of elevated vitamin B12 in clinical practice.  

PubMed

Hypercobalaminemia (high serum vitamin B12 levels) is a frequent and underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, reflecting a functional deficiency linked to qualitative abnormalities, which are related to defects in tissue uptake and action of vitamin B12. The aetiological profile of high serum cobalamin predominantly encompasses severe disease entities for which early diagnosis is critical for prognosis. These entities are essentially comprised of solid neoplasms, haematological malignancies and liver and kidney diseases. This review reflects the potential importance of the vitamin B12 assay as an early diagnostic marker of these diseases. A codified approach is needed to determine the potential indications of a search for high serum cobalamin and the practical clinical strategy to adopt upon discovery of elevated cobalamin levels. While low serum cobalamin levels do not necessarily imply deficiency, an abnormally high serum cobalamin level forms a warning sign requiring exclusion of a number of serious underlying pathologies. Functional cobalamin deficiency can thus occur at any serum level. PMID:23447660

Andrès, E; Serraj, K; Zhu, J; Vermorken, A J M

2013-02-27

70

Bound vitamin B12 absorption in patients with low serum B12 levels.  

PubMed

In many patients with low serum levels of vitamin B12, the absorption of the free vitamin has been normal. The present study, using a total body counter 57CoB12 absorption method that clearly separated those with intrinsic factor deficiency from controls, found that of 94 patients with low B12 levels and intact stomachs in whom the absorption of free and bound B12 was determined, 44 (47%) had normal absorption of both. However, 20 of the 94 (21%) with normal absorption of free B12 had low absorption of bound B12. The remainder (32%) had low absorption of both free and bound B12. All patients with high serum gastrin levels had low bound B12 absorption, but so did 21% of those patients with normal serum gastrin levels. PMID:1609768

Miller, A; Furlong, D; Burrows, B A; Slingerland, D W

1992-07-01

71

Vitamin B12 assays compared by use of patients sera with low vitamin B12 content  

SciTech Connect

The authors compared four radioisotope dilution (RD) methods and a microbiological assay for measuring concentrations of vitamin B12 in a selected panel of serum samples from patients known to be deficient in the vitamin. Low (less than 100 ng/L) and borderline (100-180 ng/L) results were similar between methods, but use of the manufacturers recommended ranges for borderline results would have changed the diagnostic classifications for 22 of 38 samples. Results of all the RD methods inter-correlated well, but less so with the microbiological assay. Borderline, nondiagnostic results were common to all methods, and no apparent advantage was gained from using the microbiological assay.

Sheridan, B.L.; Pearce, L.C.

1985-05-01

72

Hypersegmented Neutrophils and Vitamin B12 Deficiency  

Microsoft Academic Search

The sensitivities and specificities of the mean cell volume (MCV), the red cell distribution width (RDW), and blood smear hypersegmentation for B12 deficiency were reviewed in 515 patients whose B12 levels were determined. 61 patients had B12 levels less than 200 pg\\/ml. 43 patients were defined as B12 deficient (n = 13) or non- B12 deficient (n = 30). Hypersegmentation

Warren G. Thompson; Cara Cassino; Lisa Babitz; Thomas Meola; Russell Berman; Michael Freedman

1989-01-01

73

Vegetarian lifestyle and monitoring of vitamin B12 status  

Microsoft Academic Search

Vegetarians are at risk to develop deficiencies of some essential nutrients, especially vitamin B-12 (cobalamin). Cobalamin occurs in substantial amounts only in foods derived from animals and is essential for one-carbon metabolism and cell division. Low nutritional intake of vitamin B-12 may lead to negative balance and, finally, to functional deficiency when tissue stores of vitamin B-12 are depleted. Early

Wolfgang Herrmann; Jürgen Geisel

2002-01-01

74

Vitamin B12 deficiency in a breast fed infant.  

PubMed Central

We report the case of a 5 month old breast fed infant who presented with a history of vomiting, pallor, and failure to thrive. Investigations showed severe nutritional vitamin B12 deficiency with a megaloblastic pancytopenia. This deficiency was due to low vitamin B12 concentrations in the maternal breast milk, and subsequent investigations showed maternal pernicious anaemia. Treatment of the infant with vitamin B12 resulted in a rapid clinical and haematological improvement. This case represents an unusual presentation of pernicious anaemia.

McPhee, A J; Davidson, G P; Leahy, M; Beare, T

1988-01-01

75

[Selective vitamin B12 absorption disorder (Imerslund-Gräsbeck syndrome)].  

PubMed

The authors present a case of Imerslund-Gräsbeck syndrome, i. e. a familial megaloblastic anemia with proteinuria. The disease is due to congenital, selective malabsorption of vitamin B12. The subnormal absorption of vitamin B12 is not altered by orally given intrinsic factor, but parenteral vitamin B12 therapy results in complete recovery. Approximately 150 cases have been described in literature, the authors' case is the first in Hungary. PMID:1475117

Külkey, O; Reusz, G; Sallay, P; Miltényi, M

1992-12-27

76

The effect of oral contraceptives on vitamin B12 metabolism.  

PubMed

Serum vitamin vitamin B12 levels were determined in 199 women who were on a regimen of oral contraceptives of either the combination or sequential type and in a control group of 196 women. The group using oral contraceptive agents (OCA) had significantly lower serum levels of vitamin B12 vitamin as compared to those of the control group. A total of 19 women using OCAs had serum vitamin B12 levels that were lower than normal values. However, the Schilling test and urinary methylmalonate excretion in this group were normal. The OCA group had a significantly lower total serum vitamin B12 binding capacity, a lower total transcobalamin I level, and a higher transcobalamin III level. Our study suggests that the fall of serum vitamin B12 in OCA users is due to the changes in vitamin B12 binders of serum and does not represent vitamin B12 deficiency. Therefore, according to our data, there is no justification for vitamin B12 supplementation in users of oral contraceptives. PMID:474643

Shojania, A M; Wylie, B

1979-09-01

77

Involuntary movements associated with vitamin B12 deficiency  

Microsoft Academic Search

Involuntary movements are not a known feature of vitamin B12 (vB12) deficiency in adults, though they are a characteristic feature of vB12 deficiency in infants. This case report presents an adult patient with vB12 deficiency in whom, myoclonus-like muscular contractions appeared soon after the initiation of vB12 and disappeared after the first week of this therapy. To our knowledge, this

Münevver Çelik; Ça?atay Öncel; Hulki Forta

2003-01-01

78

Defect in Vitamin B12 Release from Lysosomes: Newly Described Inborn Error of Vitamin B12 Metabolism  

Microsoft Academic Search

Cultured diploid fibroblasts from a patient with a previously undescribed inborn error of cobalamin metabolism accumulate unmetabolized, nonprotein-bound vitamin B12 in lysosomes. These cells are able to endocytose the transcobalamin II- B12 complex and to release B12 from transcobalamin II. The freed vitamin B12 is not released from lysosomes into the cytoplasm of the cell. This suggests that there is

David S. Rosenblatt; Angela Hosack; Nora V. Matiaszuk; Bernard A. Cooper; Rachel Laframboise

1985-01-01

79

Effect of an injectable microencapsulated Vitamin B12 on serum and liver Vitamin B12 concentrations in calves  

Microsoft Academic Search

dAim: To evaluate the efficacy of a long-acting injectable microencapsulated formulation ofVitamin B12 in dairy calves.dMethod: Fifty calves, average liveweight 110kg, were randomly allocated to 5 groups of 10 animals and injected subcutaneously in the anterior neck with 0.12, 0.18, 0.24 and 0.3 mg Vitamin B12\\/kg liveweight using a formulation of microencapsulated Vitamin B12 in a lactide : glycolide copolymer.

N. D. Grace; D. M. West

2000-01-01

80

Oral Vitamin B12 Replacement: An Effective Treatment for Vitamin B12 Deficiency After Total Gastrectomy in Gastric Cancer Patients  

Microsoft Academic Search

Background  Vitamin B12 deficiency is a common long-term sequelae after total gastrectomy. Intramuscular injection of vitamin B12 is the\\u000a only known treatment. We investigated the efficacy and safety of oral vitamin B12 replacement for gastric cancer patients\\u000a with vitamin B12 deficiency after total gastrectomy.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We performed a single-arm, open-label, fixed-drug dosage, prospective study (NCT00699478) involving gastric cancer patients\\u000a who underwent total

Hyoung-Il Kim; Woo Jin Hyung; Ki Jun Song; Seung Ho Choi; Choong-Bai Kim; Sung Hoon Noh

81

Considering the case for vitamin B12 fortification of flour.  

PubMed

Reasons to fortify flour with vitamin B12 are considered, including the high prevalence of depletion and deficiency of this vitamin that occurs in persons of all ages in resource-poor countries and in the elderly in wealthier countries, and the adverse functional consequences of poor vitamin B12 status. From a global perspective, the main cause of inadequate intake and status is a low intake of animal-source foods; even lacto-ovo vegetarians have lower serum vitamin B12 concentrations than omnivores, and for various reasons many populations have limited consumption of animal-source foods. Infants are vitamin B12-depleted from early infancy if their mothers' vitamin B12 status and intake are poor during pregnancy and lactation. Even in the United States, more than 20% of the elderly have serum vitamin B12 concentrations that indicate depletion, and an additional 6% have deficiency, primarily due to gastric atrophy, which impairs the absorption of the vitamin from food but usually not from supplements or fortified foods. Although the evidence is limited, it shows that fortified flour, consumed as bread, can improve vitamin B12 status. Where vitamin B12 fortification is implemented, the recommendation is to add 20 microg/kg flour, assuming consumption of 75 to 100 g flour per day, to provide 75% to 100% of the Estimated Average Requirement; the amount of the vitamin that can be added is limited by its cost. The effectiveness of this level of addition for improving vitamin B12 status in programs needs to be determined and monitored. In addition, further research should evaluate the bioavailability of the vitamin from fortified flour by elderly people with food cobalamin malabsorption and gastric atrophy. PMID:20629351

Allen, Lindsay H; Rosenberg, Irwin H; Oakley, Godfrey P; Omenn, Gilbert S

2010-03-01

82

Vegetarian lifestyle and monitoring of vitamin B-12 status.  

PubMed

Vegetarians are at risk to develop deficiencies of some essential nutrients, especially vitamin B-12 (cobalamin). Cobalamin occurs in substantial amounts only in foods derived from animals and is essential for one-carbon metabolism and cell division. Low nutritional intake of vitamin B-12 may lead to negative balance and, finally, to functional deficiency when tissue stores of vitamin B-12 are depleted. Early diagnosis of vitamin B-12 deficiency seems to be useful because irreversible neurological damages may be prevented by cobalamin substitution. The search for a specific and sensitive test to diagnose vitamin B-12 deficiency is ongoing. Serum vitamin B-12 measurement is a widely applied standard method. However, the test has poor predictive value. Optimal monitoring of cobalamin status in vegetarians should include the measurement of homocysteine (HCY), methylmalonic acid (MMA), and holotranscobalamin II. Vitamin B-12 deficiency can be divided into four stages. In stages I and II, indicated by a low plasma level of holotranscobalamin II, the plasma and cell stores become depleted. Stage III is characterized by increased levels of HCY and MMA in addition to lowered holotranscobalamin II. In stage IV, clinical signs become recognizable like macroovalocytosis, elevated MCV of erythrocytes or lowered haemoglobin. In our investigations, we have found stage III of vitamin B-12 deficiency in over 60% of vegetarians, thus underlining the importance of cobalamin monitoring in this dietary group. PMID:12417096

Herrmann, Wolfgang; Geisel, Jürgen

2002-12-01

83

Erythrocyte Vitamin B12 Activity in Lactovegetarian Pregnant Indian Women  

Microsoft Academic Search

Plasma and erythrocyte vitamin B12 levels were studied in pregnant Indian women consuming very little food of animal origin and compared with healthy non-pregnant women from the same dietetic group. The comparison of the mean values for routine haematological parameters revealed distinct fall in haemoglobin, packed cell volume, plasma vitamin B12, and albumin levels in pregnant women. However, the mean

V. S. Jathar; A. B. Inamdar-Deshmukh

1981-01-01

84

Nature and nurture in vitamin B12 deficiency.  

PubMed

We report on a child in whom severe nutritional vitamin B12 deficiency was exacerbated by a genetic impairment of the folate cycle, causing reduced CSF concentrations of the methyl group donor 5-methyltetrahydrofolate. Some patients with vitamin B12 deficiency may benefit from high dose folic acid supplementation, even if plasma concentrations are high. PMID:12089131

Zschocke, J; Schindler, S; Hoffmann, G F; Albani, M

2002-07-01

85

Nature and nurture in vitamin B12 deficiency  

Microsoft Academic Search

We report on a child in whom severe nutritional vitamin B12 deficiency was exacerbated by a genetic impairment of the folate cycle, causing reduced CSF concentrations of the methyl group donor 5-methyltetrahydrofolate. Some patients with vitamin B12 deficiency may benefit from high dose folic acid supplementation, even if plasma concentrations are high.

J Zschocke; S Schindler; G F Hoffmann; M Albani

2002-01-01

86

Vitamin B12 deficiency in a breast fed infant  

Microsoft Academic Search

We report the case of a 5 month old breast fed infant who presented with a history of vomiting, pallor, and failure to thrive. Investigations showed severe nutritional vitamin B12 deficiency with a megaloblastic pancytopenia. This deficiency was due to low vitamin B12 concentrations in the maternal breast milk, and subsequent investigations showed maternal pernicious anaemia. Treatment of the infant

A J McPhee; G P Davidson; M Leahy; T Beare

1988-01-01

87

A SYSTEMIC REVIEW OF VITAMIN B12 DEFICIENCY  

Microsoft Academic Search

Background: Vitamin B12 or cobalamin deficiency has a prevalence of 12-20% in the general population and its incidence is expected to increase as the elderly population grows. Clarity on its criteria for diagnosis, evaluation and management will be useful to family physicians. A review on vitamin B12 deficiency, its evaluation and management has been attempted in this paper. Methodology: A

Siew Chee Weng

88

Effect of Vitamin B12 Treatment on Haptocorrin  

Microsoft Academic Search

Background: Haptocorrin (HC) carries the major part of circulating cobalamin, but whether HC is altered on treatment with vitamin B12 remains unknown. Methods: Our study included 3 populations: a popula- tion of vegan men (n 174; vegan population), of whom 63 were treated daily with 5 mg of oral vitamin B12 for 3 months; a group of patients with a

Anne L. Mørkbak; Anne-Mette Hvas; Tom A. B. Sanders; Øyvind Bleie; Helga Refsum; Ottar K. Nygaard; Ebba Nexø

2006-01-01

89

Regulation of phytoplankton dynamics by vitamin B12  

NASA Astrophysics Data System (ADS)

Despite the biological necessity of vitamin B12 (cobalamin), its importance in phytoplankton ecology has been ignored for nearly three decades. Here we report strong and selective responses of phytoplankton communities to varying low levels (5-87 pM) of dissolved B12 in several coastal embayments. The ecological importance of this vitamin is inferred from observed declines in dissolved B12 levels as field populations of large (>5 ?m) phytoplankton increased. In contrast, biomass of small (<5 ?m) phytoplankton varied independently of B12 concentrations. These observations were corroborated by field-based nutrient amendment experiments, in which B12 additions stimulated growth of large phytoplankton taxa 6-fold over unamended controls. In contrast, small taxa (<5 ?m) were largely unaffected. This study provides the first evidence of vitamin B12's influence on phytoplankton field population dynamics based on direct chemical measurements of cobalamin, and implicates B12 as an important organic regulator of photoautotrophic fertility in marine systems.

Sañudo-Wilhelmy, S. A.; Gobler, C. J.; Okbamichael, M.; Taylor, G. T.

2006-02-01

90

Does an elevated serum vitamin B(12) level mask actual vitamin B(12) deficiency in myeloproliferative disorders?  

PubMed

Elevation of the methylmalonic acid level is a sensitive marker of vitamin B(12) deficiency. Our cross-sectional observational study of 33 patients with myeloproliferative disorders found that 9 patients, 27.27% had occult deficiency despite having normal to elevated serum vitamin B(12) levels. Early detection of vitamin B(12) deficiency by using the methylmalonic acid measurement may prevent significant neurologic and hematologic complications in patients with myeloproliferative disorders. In patients with myeloproliferative disorders, normal to high serum vitamin B(12) concentrations have often been reported. The primary objective of this study was to determine whether normal or elevated serum vitamin B(12) levels in myeloproliferative disorders might actually mask the true underlying vitamin B(12) deficiency in some patients. Thirty-three patients (12 men, 21 women; mean age, 70.55 years [range, 37-90 years]) with polycythemia vera (n = 13), essential thrombocythemia (n = 12), chronic myelogenous leukemia (n = 5), and idiopathic myelofibrosis (IMF) (n = 3) were accrued over a period of 1 year, from March 2009 to February 2010. From all of the subjects, serum vitamin B(12) level, methylmalonic acid level, a basic complete blood cell count panel, and liver and renal function tests were obtained. Normal to elevated serum vitamin B(12) levels were recorded in all the patients. However, elevated serum methylmalonic acid levels were found in 9 (27.27%) patients, with a prevalence of 2 patients with polycythemia vera, 23% in polycythemia vera, 4 patients with essential thrombocythemia, 33.3% in essential thrombocythemia, 1 patient with chronic myelogenous leukemia, 20% in chronic myelogenous leukemia, and 2 patients with idiopathic myelofibrosis, 66.7% in IMF. Our data suggest that 27.27% of the total enrolled patients had occult vitamin B(12) deficiency despite normal to elevated vitamin B(12) levels on regular serum vitamin B(12) testing. PMID:22424943

Gauchan, Dron; Joshi, Nitin; Gill, Amandeep Singh; Patel, Vishal; Debari, Vincent A; Guron, Gunwant; Maroules, Michael

2012-03-16

91

[Vitamin B12 deficiency due to abnormal eating habits].  

PubMed

Vitamin B12 deficiency is an uncommon disorder in a prosperous western country. In two children a nutritional vitamin B12 deficiency was observed. The first was a 2-year-old girl with neurodevelopmental regression and macrocytic anaemia, a result of a combination of a maternal vitamin B12 deficiency and inadequate feeding after birth. The second patient was a 14-year-old adipose girl with severe polyneuropathy and mild macrocytic anaemia as a result of a nutritional vitamin B12 deficiency. In her case the deficiency resulted from a bizarre feeding pattern. She turned out to be the victim of child abuse. It is concluded that even in a prosperous western country like the Netherlands vitamin B12 deficiency in children can develop as a result of an inadequate feeding pattern. It can lead not only to macrocytic anaemia but also to severe neurological abnormalities. PMID:8133949

Prakken, A B; Veenhuizen, L; Bruin, M C; Waelkens, J J; van Dijken, P J

1994-02-26

92

Nutritional vitamin B12 deficiency in hospitalized young children.  

PubMed

The authors sought to determine prevalence, social, economic, and dietary patterns of young children (n = 20) identified as having vitamin B12 deficiency anemia after admission to their hospital in the last 3 years. The diagnosis of vitamin B12 deficiency was based on symptoms and clinical findings, findings on peripheral blood films and bone marrow aspirates, and serum levels of vitamin B12. The children had been exclusively breast-fed without any animal food supplementation. Serum vitamin B12 levels were also measured in the sera of mothers and found to be low. The authors concluded that vitamin B12 deficiency might be an important health problem among children of mothers who do not consume animal foods adequately. PMID:17130110

Cetinkaya, Feyzullah; Yildirmak, Yildiz; Kutluk, Gunsel; Erdem, Ela

93

Regulation of phytoplankton dynamics by vitamin B12  

Microsoft Academic Search

Despite the biological necessity of vitamin B12 (cobalamin), its importance in phytoplankton ecology has been ignored for nearly three decades. Here we report strong and selective responses of phytoplankton communities to varying low levels (5-87 pM) of dissolved B12 in several coastal embayments. The ecological importance of this vitamin is inferred from observed declines in dissolved B12 levels as field

S. A. Sañudo-Wilhelmy; C. J. Gobler; M. Okbamichael; G. T. Taylor

2006-01-01

94

Erythropoietin Resistance due to Vitamin B12 Deficiency  

Microsoft Academic Search

We describe the first reported case of resistance to human recombinant erythropoietin (rhEPO) treatment caused by vitamin B12 deficiency in a chronic hemodialysis patient. Despite a normal B12 level before rhEPO treatment, resistant anemia together with a low B12 level and a megaloblastic bone marrow developed after only 8 months of rhEPO. There was a rapid reticulocyte response to B12

Pierre Zachee; Shern L. Chew; Ronald Daelemans; Robert L. Lins

1992-01-01

95

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

96

THE EFFECTS OF A VITAMIN B12 SUPPLEMENT, VITAMIN B12 AND STREPTOMYCIN ON THE METABOLISM OF THE RAT 1  

Microsoft Academic Search

Much attention has been focused on recent reports in which crude vitamin B12 (animal protein factor) supplements, as well as pure vitamin B12 and antibiotics, have been included in rations for chickens and swine, the claim being made, as a result of this work, that the animals gained weight more rapidly and usually more efficiently than did other animals consuming

ALEX BLACK; JOHN W. BEATZLER

97

Vitamin B12 deficiency after gastric surgery for obesity13  

Microsoft Academic Search

Low serum vitamin B-12 concentrations after gastric bypass (GB) surgery for obesity were observed in I 1 of 28 patients without detectable impairment of crystalline vitamin B- 12 absorption. This was observed in 2 of 19 patients with vertical banded gastroplasty (VBG). In contrast, protein-bound vitamin B-l2 absorption was markedly impaired, as demonstrated in eight of these patients after GB

Barbara M Rhode; Paul Arseneau; Bernard A Cooper; Max Katz; Brian M Gilfix; Lloyd D MacLean

98

Synthesis, characterization and pharmacodynamics of vitamin-B(12)-conjugated glucagon-like peptide-1.  

PubMed

Clearing the way: Glucagon-like peptide-1 (GLP-1) receptor agonists are proving a potent weapon in the treatment of type II diabetes. A new vitamin B(12)-GLP-1 conjugate is investigated and shown to have insulinotropic properties similar to the unmodified peptide. These results are critical to the exploitation of the vitamin B(12) oral uptake pathway for peptide delivery. PMID:23203941

Clardy-James, Susan; Chepurny, Oleg G; Leech, Colin A; Holz, George G; Doyle, Robert P

2012-11-30

99

Transcobalamin 776C3G polymorphism negatively affects vitamin B12 metabolism1-3  

Microsoft Academic Search

Background: A common genetic polymorphism (transcobalamin (TC) 776C3G) may affect the function of transcobalamin, the pro- tein required for vitamin B-12 cellular uptake and metabolism. Re- methylation of homocysteine is dependent on the production of 5-methyltetrahydrofolate and adequate vitamin B-12 for the methi- onine synthase reaction. Objectives: The objectives were to assess the influence of the TC 776C3 G polymorphism

Kristina M von Castel-Dunwoody; Karla P Shelnutt; Jaimie D Vaughn; Elizabeth R Griffin; David R Maneval; Douglas W Theriaque; Lynn B Bailey

100

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 ...

101

Vitamin B12 levels in erythrocytes in hypochromic anaemia  

PubMed Central

Vitamin B12 levels in erythrocytes were low in untreated hypochromic anaemia, rose to abnormally high levels during therapy with iron alone, and finally slowly fell to normal. These changes were similar to those previously found in pernicious anaemia in response to vitamin B12 therapy and in folate-deficiency anaemia in response to folic acid, thus changes in erythrocyte B12 levels are not always due directly to changes in B12 metabolism but may be secondary to changes in the levels of other haematinic factors.

Harrison, R. J.

1971-01-01

102

Vitamin B12 deficiency in a breast fed infant.  

PubMed

We report the case of a 5 month old breast fed infant who presented with a history of vomiting, pallor, and failure to thrive. Investigations showed severe nutritional vitamin B12 deficiency with a megaloblastic pancytopenia. This deficiency was due to low vitamin B12 concentrations in the maternal breast milk, and subsequent investigations showed maternal pernicious anaemia. Treatment of the infant with vitamin B12 resulted in a rapid clinical and haematological improvement. This case represents an unusual presentation of pernicious anaemia. PMID:3415328

McPhee, A J; Davidson, G P; Leahy, M; Beare, T

1988-08-01

103

Competitive immunoassay for analysis of vitamin B(12).  

PubMed

In the current work, direct competitive enzyme-linked immunosorbent assay (ELISA) was developed for derivatized vitamin B(12) by generating chicken egg yolk immunoglobulins (IgY) against derivatized vitamin B(12) and purified using affinity chromatography. Checkerboard assay was performed with vitamin B(12) antibody and vitamin B(12)-alkaline phosphatase conjugate followed by its conjugate characterization using ultraviolet (UV) spectroscopy and high-performance liquid chromatography (HPLC). The limit of detection was 10 ng/ml with a linear working range of 10 to 10,000 ng/ml. The affinity constant (K(a)) of the vitamin B(12) antibody was found to be 4.23×10(8) L/mol. Cross-reactivity with other water-soluble vitamins was found to be less than 0.01% except for analogs of vitamin B(12) that showed 12% to 35%. The intra- and interassay coefficients of variation were found to be in the ranges from 0.0005% to 1.2% and 0.009% to 1.03%, respectively. The assay was validated with the HPLC method in terms of sensitivity, specificity, precision, and recovery of vitamin B(12) with spiked multivitamin injections, tablets, capsules, and chocolates. The HPLC method had a detection limit of 500 ng/ml with a linear working range of 1000 to 10,000 ng/ml. After extraction of vitamin B(12) using Amberlite XAD, the developed ELISA method correlated well with the established HPLC method with a correlation coefficient of 0.90. PMID:21816132

Selva Kumar, L Sagaya; Thakur, M S

2011-07-26

104

Brain damage in infancy and dietary vitamin B12 deficiency.  

PubMed

A case of the exclusively breast-fed infant of a vegetarian mother is reported. Neurological deterioration commenced between three and six months of age, and progressed to a comatose premoribund state by the age of nine months. Investigations revealed a mild nutritional vitamin B12 deficiency in the mother, and a very severe nutritional B12 deficiency in the infant, with severe megaloblastic anaemia. Treatment of the infant with vitamin B12 resulted in a rapid clinical and haematological improvement, but neurological recovery was incomplete. Evidence is presented that dietary B12 deficiency was the sole cause of the infant's deterioration, and the literature relating to the condition is reviewed. It is recommended that all strict vegetarians (vegans), especially women in the child-bearing age group, take vitamin B12 supplements. PMID:502936

Wighton, M C; Manson, J I; Speed, I; Robertson, E; Chapman, E

1979-07-14

105

Amegakaryocytic thrombocytopenia of nutritional vitamin B12 deficiency.  

PubMed

Description of a case of amegakaryocytic thrombocytopenia due to nutritional vitamin B12 deficiency. Megakaryocytes reappeared in the bone marrow after specific treatment and other haematological responses were prompt. PMID:3407007

Ghosh, K; Sarode, R; Varma, N; Varma, S; Garewal, G

1988-04-01

106

21 CFR 862.1810 - Vitamin B 12 test system.  

Code of Federal Regulations, 2013 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1810 Vitamin B 12 test system. (a) Identification....

2013-04-01

107

Radioisotope Dilution Assay for Vitamin B12 Experiences.  

National Technical Information Service (NTIS)

Serum with a high unsaturated Transcobalamine I: Transcobalamine II ratio from patients with chronic myelocytic leukemia was used as the binder for a radioactive isotope dilution assay of serum vitamin B12 by the method of Rothenberg. This method distingu...

G. M. Dudley C. A. Coltman

1968-01-01

108

Reductive Dechlorination of Chlorophenols by Vitamin B12.  

National Technical Information Service (NTIS)

The reductive dechlorination of chlorinated phenols by vitamin B12, supported by the reductant Ti(III) citrate, was examined. Procedures were developed, including a novel reactor system, for conducting these experiments. Most of the experiments were condu...

M. H. Smith

1993-01-01

109

Vitamin B12 in the Serum of the Rhesus Monkey  

Microsoft Academic Search

MOST investigations of the physiology of vitamin B12 have been carried out in man or laboratory animals other than the sub-human primates. Indeed, it has been specifically noted that vitamin B12 deficiency has not been produced experimentally in monkeys1-3, and those macrocytic anæmias which have been induced are known to respond to treatment with folic acid (sometimes in association with

P. L. Krohn; C. E. Oxnard

1963-01-01

110

Lipid Metabolism in the Vitamin-B12 Deprived Rat  

Microsoft Academic Search

Rats were deprived of vitamin B12 in order to study the effect of this deprivation on the metabolism of lipids in the liver and the nervous system. Serum vitamin B12 concentrations of 102.7 and 78 pg\\/ml were found at sacrifice after 5 and 6 months, respectively. Neurological testing failed to reveal signs of neuropathy. The total liver lipids were decreased

Clas Fehling; Margaretha Jägerstad; Gösta Arvidson

1978-01-01

111

Down beat nystagmus in vitamin B 12 deficiency syndrome.  

PubMed

A 34 years old male, presenting with progressive proximal weakness, with a neurogenic pattern on needle EMG, and a family history suggestive of an autosomal recessive disorder, was found to have additional features of myeloneuropathy and a down beat nystagmus. A low serum vitamin B12 level was found, and on vitamin B12 supplementation there was a partial clinical as well as electrophysiological recovery. PMID:16795999

Puri, V; Chaudhry, N; Satyawani, M

112

Vitamin B12 deficiency in untreated celiac disease  

Microsoft Academic Search

OBJECTIVES:Iron and folate malabsorption are common in untreated celiac disease as the proximal small intestine is predominantly affected. Vitamin B12 deficiency is thought to be uncommon, as the terminal ileum is relatively spared. This study aims to investigate the prevalence of vitamin B12 deficiency in patients with untreated celiac disease.METHODS:Prospective study of 39 consecutive biopsy-proven celiac disease patients (32 women,

Anna Dahele; Subrata Ghosh

2001-01-01

113

Effect of Orotic Acid on Vitamin B12-deficient Rats  

Microsoft Academic Search

STUDIES in this laboratory1,2 have recently shown that orotic acid is a factor for growth and survival in rats depleted of the animal protein factor of casein. Also, vitamin B12 has a protective effect on the deficiency in animal protein factor3. This indicates a relationship, from a nutritional point of view, between vitamin B12 and orotic acid. In the present

M. Marchetti; R. Viviani; A. Rabbi

1956-01-01

114

Experiences with dual protein bound aqueous vitamin B12 absorption test in subjects with low serum vitamin B12 concentrations.  

PubMed Central

A dual isotope vitamin B12 absorption test in which vitamin B12 is given both in aqueous solution and bound to protein (chicken serum), was evaluated in 26 controls and 68 patients with subnormal serum vitamin B12 concentrations (19 with pernicious anaemia, 13 with iron deficiency, seven after partial gastrectomy, seven with malabsorptive states, five with folate deficiency, four with chronic alcoholism and 13 in whom no cause was apparent). In control patients protein bound absorption decreased with age; isotope excretion was 1.0% or over in those aged under 60 and 0.5% or over in those aged 60 and above. Malabsorption of protein bound vitamin B12 with normal aqueous absorption occurred in five patients with iron deficiency, three with alcoholism, two after partial gastrectomy, two with folate deficiency and in one with a malabsorptive state. In alcoholics abstinence produced an improvement in protein bound absorption. All patients in the group for whom no cause could be found for the subnormal serum vitamin B12 concentration had normal aqueous absorption but four had malabsorption of protein bound vitamin. Although the dual isotope test gave reproducible results and was consistent with the standard Schilling test some anomalies were detected; nine patients had reduced aqueous absorption with normal protein bound absorption. Despite this the dual test may prove useful in determining the importance of a subnormal vitamin B12 concentration where the cause is not clinically apparent. Further development is needed before it can be considered for routine use.

Gozzard, D I; Dawson, D W; Lewis, M J

1987-01-01

115

Experiences with dual protein bound aqueous vitamin B12 absorption test in subjects with low serum vitamin B12 concentrations.  

PubMed

A dual isotope vitamin B12 absorption test in which vitamin B12 is given both in aqueous solution and bound to protein (chicken serum), was evaluated in 26 controls and 68 patients with subnormal serum vitamin B12 concentrations (19 with pernicious anaemia, 13 with iron deficiency, seven after partial gastrectomy, seven with malabsorptive states, five with folate deficiency, four with chronic alcoholism and 13 in whom no cause was apparent). In control patients protein bound absorption decreased with age; isotope excretion was 1.0% or over in those aged under 60 and 0.5% or over in those aged 60 and above. Malabsorption of protein bound vitamin B12 with normal aqueous absorption occurred in five patients with iron deficiency, three with alcoholism, two after partial gastrectomy, two with folate deficiency and in one with a malabsorptive state. In alcoholics abstinence produced an improvement in protein bound absorption. All patients in the group for whom no cause could be found for the subnormal serum vitamin B12 concentration had normal aqueous absorption but four had malabsorption of protein bound vitamin. Although the dual isotope test gave reproducible results and was consistent with the standard Schilling test some anomalies were detected; nine patients had reduced aqueous absorption with normal protein bound absorption. Despite this the dual test may prove useful in determining the importance of a subnormal vitamin B12 concentration where the cause is not clinically apparent. Further development is needed before it can be considered for routine use. PMID:3611394

Gozzard, D I; Dawson, D W; Lewis, M J

1987-06-01

116

The electronic structure and chemical bonding of vitamin B12  

NASA Astrophysics Data System (ADS)

The electronic structure and chemical bonding of vitamin B12 (cyanocobalamin) and B12-derivative (methylcobalamin) are studied by means of X-ray emission (XES) and photoelectron (XPS) spectroscopy. The obtained results are compared with ab initio electronic structure calculations using the orthogonalized linear combination of the atomic orbital method (OLCAO). We show that the chemical bonding in vitamin B12 is characterized by the strong Co-C bond and relatively weak axial Co-N bond. It is further confirmed that the Co-C bond in cyanocobalamin is stronger than that of methylcobalamin resulting in their different biological activity.

Kurmaev, E. Z.; Moewes, A.; Ouyang, L.; Randaccio, L.; Rulis, P.; Ching, W. Y.; Bach, M.; Neumann, M.

2003-05-01

117

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...

118

THE EXCRETION OF VITAMIN B12 BY DAIRY CATTLE  

Microsoft Academic Search

HERE is abundant evidence that vitamin B12 occurs in consider- able quantity in the feces of ruminants. That most of it is syn- thesized by microorganisms in the digestive tract is highly probable. It has been demonstrated, for example, (Pearson et al., 1953) that relatively large amounts of this vitamin are synthesized in the gastro- intestinal tract of sheep. For

A. E. TEERI; H. F. ENos; E. POMERANTZ; N. F. CoLovos

119

Ethylenediamine Tetraacetate and the Intestinal Absorption of Vitamin B12  

Microsoft Academic Search

FOR the laboratory, as opposed to the clinical, analysis of the defective absorption of vitamin B12 in pernicious anæmia caused by the lack of Castle's intrinsic factor, several methods have been developed since radioactive preparations of the vitamin became available. In the first the absorption is studied by measuring the radioactivity of the fæces produced by gastrectomized rats given a

J. Abels; M. G. Woldring; H. O. Nieweg; J. G. Faber; J. A. de Vries

1959-01-01

120

Absorption of Vitamin B12 from the Rat Intestine  

Microsoft Academic Search

MANY animal tissues contain specific protein-like substances that combine with vitamin B12. The availability of the vitamin in this bound form when given by mouth to animals depends on the origin of the binding material. Homologous bound forms are fully available, whereas a similar preparation from a different species may not be1.

E. S. Holdsworth; M. E. Coates

1956-01-01

121

Vitamin-B12 deficiency following therapy in gynecologic oncology  

SciTech Connect

Vitamin-B12 deficiency results from inadequate absorption of the vitamin by the distal ileum and depletion of available stores. Both radiotherapy and intestinal resection can contribute to development of this condition. The significance of this problem in gynecologic oncology is discussed and two patients are described.

Bandy, L.C.; Clarke-Pearson, D.L.; Creasman, W.T.

1984-03-01

122

Two newborns with nutritional vitamin B12 deficiency: challenges in newborn screening for vitamin B12 deficiency.  

PubMed

Vitamin B12 deficiency causes decreased Methionine Synthase and L-Methylmalonyl-CoA Mutase activity and results in accumulation of Homocysteine, Methylmalonic acid and Propionylcarnitine. Propionylcarnitine is included in tandem mass spectrometry-based newborn screening programs for detection of certain inborn errors of metabolism. We report two asymptomatic newborns with Vitamin B12 deficiency due to maternal deficiencies. One was detected incidentally at 3 weeks of age; the second on supplemental newborn screening based on elevated Propionylcarnitine at 2 days of age. This illustrates the potential for false negative results for Vitamin B12 deficiency screening by acylcarnitine profiling in newborn screening. Homocysteine and Methylmalonic acid may be better markers of Vitamin B12 deficiency. In conclusion, we suggest measuring Methylmalonic acid, Propionylcarnitine and Homocysteine levels in blood spots in expanded newborn screening in order to detect asymptomatic newborns with Vitamin B12 deficiency. Further studies are needed to establish the sensitivity of these three markers in screening for Vitamin B12 deficiency. PMID:16464760

Campbell, C D; Ganesh, J; Ficicioglu, C

2005-12-01

123

Long-Term Effects of Vitamin B12, Folate, and Vitamin B6 Supplements in Elderly People with Normal Serum Vitamin B12 Concentrations  

Microsoft Academic Search

Background: In the elderly, deficiencies of folate, cobalamin (vitamin B12) and pyridoxal phosphate (vitamin B6) are common. The metabolites homocysteine, methylmalonic acid, 2-methylcitric acid and cystathionine have been reported to be sensitive markers of these vitamin deficiencies. Objective: The long-term (269 days) effect of an intramuscular vitamin supplement containing 1 mg vitamin B12, 1.1 mg folate, and 5 mg vitamin

Bernhard F. Henning; Martin Tepel; Reiner Riezler; Hans J. Naurath

2001-01-01

124

Association of Biochemical B12 Deficiency With Metformin Therapy and Vitamin B12 Supplements  

PubMed Central

OBJECTIVE To describe the prevalence of biochemical B12 deficiency in adults with type 2 diabetes taking metformin compared with those not taking metformin and those without diabetes, and explore whether this relationship is modified by vitamin B12 supplements. RESEARCH DESIGN AND METHODS Analysis of data on U.S. adults ?50 years of age with (n = 1,621) or without type 2 diabetes (n = 6,867) from the National Health and Nutrition Examination Survey (NHANES), 1999–2006. Type 2 diabetes was defined as clinical diagnosis after age 30 without initiation of insulin therapy within 1 year. Those with diabetes were classified according to their current metformin use. Biochemical B12 deficiency was defined as serum B12 concentrations ?148 pmol/L and borderline deficiency was defined as >148 to ?221 pmol/L. RESULTS Biochemical B12 deficiency was present in 5.8% of those with diabetes using metformin compared with 2.4% of those not using metformin (P = 0.0026) and 3.3% of those without diabetes (P = 0.0002). Among those with diabetes, metformin use was associated with biochemical B12 deficiency (adjusted odds ratio 2.92; 95% CI 1.26–6.78). Consumption of any supplement containing B12 was not associated with a reduction in the prevalence of biochemical B12 deficiency among those with diabetes, whereas consumption of any supplement containing B12 was associated with a two-thirds reduction among those without diabetes. CONCLUSIONS Metformin therapy is associated with a higher prevalence of biochemical B12 deficiency. The amount of B12 recommended by the Institute of Medicine (IOM) (2.4 ?g/day) and the amount available in general multivitamins (6 ?g) may not be enough to correct this deficiency among those with diabetes.

Reinstatler, Lael; Qi, Yan Ping; Williamson, Rebecca S.; Garn, Joshua V.; Oakley, Godfrey P.

2012-01-01

125

Vitamin B12 assimilation from chicken meat\\  

Microsoft Academic Search

Chicken meat labeled in vivo with radio-B,2 was ingested by normal volunteers. The absorption, measured by the fecal excretion method, was similar to that reported for crystalline radiocyanocobalarnin and for mutton, but exceeded that from eggs. Parenteral injection of 1000 ?g of nonlabeled vitamin B,2 did not interfere with the absorption of the radio- B,2 from the meat. The urinary

A. Doscherholmen; J. McMahon; D. Ripley

126

Thermotoga lettingae Can Salvage Cobinamide To Synthesize Vitamin B12.  

PubMed

We recently reported that the Thermotogales acquired the ability to synthesize vitamin B12 by acquisition of genes from two distantly related lineages, Archaea and Firmicutes (K. S. Swithers et al., Genome Biol. Evol. 4:730-739, 2012). Ancestral state reconstruction suggested that the cobinamide salvage gene cluster was present in the Thermotogales' most recent common ancestor. We also predicted that Thermotoga lettingae could not synthesize B12 de novo but could use the cobinamide salvage pathway to synthesize B12. In this study, these hypotheses were tested, and we found that Tt. lettingae did not synthesize B12 de novo but salvaged cobinamide. The growth rate of Tt. lettingae increased with the addition of B12 or cobinamide to its medium. It synthesized B12 when the medium was supplemented with cobinamide, and no B12 was detected in cells grown on cobinamide-deficient medium. Upstream of the cobinamide salvage genes is a putative B12 riboswitch. In other organisms, B12 riboswitches allow for higher transcriptional activity in the absence of B12. When Tt. lettingae was grown with no B12, the salvage genes were upregulated compared to cells grown with B12 or cobinamide. Another gene cluster with a putative B12 riboswitch upstream is the btuFCD ABC transporter, and it showed a transcription pattern similar to that of the cobinamide salvage genes. The BtuF proteins from species that can and cannot salvage cobinamides were shown in vitro to bind both B12 and cobinamide. These results suggest that Thermotogales species can use the BtuFCD transporter to import both B12 and cobinamide, even if they cannot salvage cobinamide. PMID:24014541

Butzin, Nicholas C; Secinaro, Michael A; Swithers, Kristen S; Gogarten, J Peter; Noll, Kenneth M

2013-09-06

127

Assessment of the Vitamin B12 Status of Pregnant Women in Nigeria Using Plasma Holotranscobalamin  

PubMed Central

Maternal vitamin B12 deficiency during pregnancy is an independent risk factor for neural tube defects and other neurological problems in infants. We determined the vitamin B12 status of 143 pregnant women in Nigeria representing all trimesters who presented to an antenatal clinic in Jos, Nigeria, using holotranscobalamin II levels (holoTCII), which is a measure of the vitamin B12 that is available for uptake into tissues. The holoTCII concentration ranged from 13 to 128?pmol/L. Using a cutoff of 40?pmol/L, 36% of the women were classified as vitamin B12-deficient. HoloTCII concentrations correlated negatively with plasma homocysteine levels (r = ?0.24, P = 0.003) and positively with red blood cell folate concentrations (r = 0.28, P < 0.001). These data underscore the importance of supplementing pregnant women in Nigeria with vitamin B12 in order to ensure adequate vitamin B12 status and decrease the risk for neural tube defects.

VanderJagt, Dorothy J.; Ujah, Innocent A. O.; Ikeh, Eugene I.; Bryant, Jessica; Pam, Victor; Hilgart, Amelia; Crossey, Michael J.; Glew, Robert H.

2011-01-01

128

Neurologic findings of nutritional vitamin B12 deficiency in children.  

PubMed

We report herein our interesting case series of 15 infants admitting with neurological symptoms who were found to have vitamin B12 deficiency. Infants who were admitted to our hospital between 2004 and 2007 with neurological symptoms and were found to have vitamin B12 deficiency were included in this study. Data regarding clinical and laboratory features were obtained. Of 15 infants, 9 were boys (60%) and 6 were girls (40%). The mean age was 11.7 months. Anorexia, pallor, hypotonia, and neurodevelopmental retardation were present in all infants. Seizures and tremor were observed in 46.6% (7/15) and 33% (5/15) of patients, respectively. Seizures were generalized tonic-clonic in 4 patients, generalized tonic in 1 patient and focal in 2 patients. Four patients had tremor on admission and 1 patient had occurrence after vitamin B12 treatment. Vitamin B12 deficiency may lead to serious neurological deficits in addition to megaloblastic anemia. Persistent neurological damage can be prevented with early diagnosis and treatment. We believe that a thorough clinical and neurological assessment might prevent failure to notice rare but possible vitamin B12 deficiency in infants with neurological deficits and neurodevelopmental retardation. PMID:20402062

Incecik, Faruk; Hergüner, M Ozlem; Altunba?ak, Sakir; Leblebisatan, Göksel

129

[Megaloblastic-vitamin B12 deficiency anemia in childhood].  

PubMed

Megaloblastic anemias are basically caused by vitamin B(12) and/or folic acid deficiency. Childhood vitamin B(12) deficiency is extremely rare. There are congenital and acquired forms of vitamin B(12)-deficiency anemias. The article captures findings of 10 year observation of 3 patients with Imerslund-Gräsbeck Syndrome (congenital chronic megaloblastic anemia with proteinuria), in which the diagnosis was established by us in early childhood and due to correct treatment and prevention complete clinical-laboratory remission is kept so far. We have also observed rare case of acquired megaloblastic anemia - 14 years old vegetarian patient, who was diagnosed with vitamin B(12)-deficiency anemia based on history, clinical and para-clinical data. It was caused by strict vegetarianism of the patient. Therefore first of all the diet was corrected. In 5 days of specific treatment with vitamin B(12) "reticulocyte crisis" was manifested (proving the correctness of diagnosis and treatment) and complete clinical-hematological remission was achieved in 2 weeks. The given cases are interesting as megaloblastic anemias in childhood are both rare and difficult to diagnose. In such cases timely diagnosis, treatment and prevention tactics should be based on cause-and-effect relation of disease. PMID:19556642

Mtvarelidze, Z G; Kvezereli-Kopadze, A N; Kvezereli-Kopadze, M A

2009-05-01

130

Oral contraceptives: effect of folate and vitamin B12 metabolism.  

PubMed Central

Women who use oral contraceptives have impaired folate metabolism as shown by slightly but significantly lower levels of folate in the serum and the erythrocytes and an increased urinary excretion of formiminoglutamic acid. The vitamin B12 level in their serum is also significantly lower than that of control groups. However, there is no evidence of tissue depletion of vitamin B12 associated with the use of oral contraceptives. The causes and clinical significance of the impairment of folate and vitamin B12 metabolism in these women is discussed in this review of the literature. Clinicians are advised to ensure that women who shop taking "the pill" because they wish to conceive have adequate folate stores before becoming pregnant.

Shojania, A. M.

1982-01-01

131

Prevalence of vitamin B12 depletion and deficiency in Liechtenstein.  

PubMed

OBJECTIVE: Data about vitamin B12 (B12) deficiency in the general population are scarce. The present study was performed to determine the prevalence of B12 deficiency in the general population of the Principality of Liechtenstein, as well as to identify sub-populations potentially at high risk. DESIGN: Retrospective study. SETTING: Ambulatory setting, population of the Principality of Liechtenstein. SUBJECTS: Seven thousand four hundred and twenty-four patients seeking medical attention whose serum samples were referred for routine work-up in an ambulatory setting were consecutively enrolled. Serum total B12 was determined in all patients in this cohort. In addition, for a subgroup of 1328 patients, serum holotranscobalamin was also measured. Prevalence of B12 deficiency was calculated. Further, multivariate logistical regression models were applied to identify covariates independently associated with B12 deficiency and depletion. RESULTS: Nearly 8 % of the general population was suffering from either B12 depletion or deficiency. The ratio between B12 depletion and deficiency was 2:1 for all age ranges. Pathological changes were detected predominantly in older people. Female gender was a significant predictor of B12 depletion. In the cohort, nearly 40 % exhibited either depletion or deficiency of B12. CONCLUSIONS: B12 depletion and deficiency are common in Liechtenstein, a Central European country. The measurement of biochemical markers represents a cost-efficient and valid assessment of the B12 state. When a deficiency of B12 is diagnosed at an early stage, many cases can be treated or prevented, with beneficial effects on individual outcomes and subsequent potential reductions in health-care costs. PMID:23237337

Koenig, Victoria; Stanga, Zeno; Zerlauth, Manfred; Bernasconi, Luca; Risch, Martin; Huber, Andreas; Risch, Lorenz

2012-12-14

132

Gel Filtration Studies of Serum B12 Binding: An Abnormal Pattern in Patients with Vitamin B12 Deficiency  

Microsoft Academic Search

T HE VITAMIN B12-BINDING ACTIVITY of serum can be separated into two fractions by each of several different technics used for fractionating serum proteins. Electrophoretic separation of serum yields an aglobulin frac- tion that binds most of the circulating endogenous vitamin B12 and a \\/3 globu- lin fraction that, in normal serum, binds virtually all vitamin B12 added in vitro.?8

CHRISTLNE LAWRENCE

1969-01-01

133

Does long-term PPI use result in vitamin B12 deficiency in elderly individuals?  

Microsoft Academic Search

Vitamin B12 deficiency is common, and increases in prevalence with increasing age. Several risk factors predispose to vitamin B12 deficiency, many of which are caused by reduced gastric acidity, which prevents the release of vitamin B12 from food. Chronic use of PPIs is associated with prolonged intended gastric acid suppression, which interferes with the initial step in vitamin B12 absorption.

Edward P Norkus; TS Dharmarajan

2008-01-01

134

Vitamin B12 Analogues, Homocysteine, Methylmalonic Acid, and Transcobalamins in the Study of Vitamin B12 Deficiency in Primary Degenerative Dementia  

Microsoft Academic Search

B12 analogues, homocysteine, methylmalonic acid (MMA), and unsaturated transcobalamins, all potential markers of vitamin B12 status, were analyzed in blood and cerebrospinal fluid (CSF) from 22 patients with primary degenerative dementia of Alzheimer type. The level of active vitamin B12 in serum correlated significantly with serum homocysteine, serum MMA, and CSF homocysteine. CSF B12 correlated significantly with serum homocysteine and

B. Regland; L. Abrahamsson; C. G. Gottfries; E. Magnus

1990-01-01

135

Association between vitamin B12 intake and EURRECA’s prioritized biomarkers of vitamin B12 in young populations: a systematic review (Online first)  

Microsoft Academic Search

Objective To review evidence on the associations between vitamin B12 intake and its biomarkers, vitamin B12 intake and its functional health outcomes, and vitamin B12 biomarkers and functional health outcomes. Design A systematic review was conducted by searching electronic databases, until January 2012, using a standardized strategy developed in the EURRECA network. Relevant articles were screened and sorted based on

I. Iglesia; R. A. M. Dhonukshe-Rutten; S. Bel-Serrat; E. L. Doets; A. J. E. M. Cavelaars; Veer van t P; M. Nissenshohn; V. Benetou; M. Hermoso; C. Berti; Groot de C. P. G. M; L. A. Moreno

2012-01-01

136

Effect of Therapy with Vitamin B12 and Folic Acid on Elderly Patients with Low Concentrations of Serum Vitamin B12 or Erythrocyte Folate but Normal Blood Counts  

Microsoft Academic Search

To help understand the haematological significance of the low concentrations of serum vitamin B12 and erythrocyte folate occurring in elderly patients, 17 acute admissions to a geriatric unit with a low concentration of serum vitamin B12 or erythrocyte folate but a normal blood count were treated with vitamin B12 and folic acid for 3 months. Bone marrow deoxyuridine supression was

J. H. Matthews; D. M. Clark; G. M. Abrahamson

1988-01-01

137

Neurological changes in fruit bats deficient in vitamin B12  

Microsoft Academic Search

HAEMATOLOGICAL and neurological sequelae are the two major effects of vitamin B12 deficiency in man. In the haemopoietic system, megaloblastic change leading to anaemia seems to be caused by deranged DNA synthesis1. The cause of central nervous system demyelination, however, is unknown and progress in this area has been hampered by the lack of a suitable experimental animal model. We

Ralph Green; Susan V. van Tonder; G. Julien Oettle; Gillian Cole; Jack Metz

1975-01-01

138

[Neurological signs due to isolated vitamin B12 deficiency].  

PubMed

Isolated vitamin B12 deficiency is a common condition in elderly patients but uncommon in patients younger than 30 years, with an average age of onset between 60 and 70 years. This is because the dietary cobalamin, which is normally split by enzymes in meat in the presence of hydrochloric acid and pepsin in the stomach, is not released in the stomachs of elderly patients, usually due to achlorhydria. Although the body may be unable to release cobalamin it does retain the ability to absorb vitamin B12 in its crystalline form, which is present in multivitamin preparations. Other causes are due to drugs that suppress gastric acid production. Neurological signs of vitamin B12 deficiency can occur in patients with a normal haematocrit and red cell indices. They include paresthesia, loss of sensation and strength in the limbs, and ataxia. Reflexes may be slowed down or increased. Romberg and Babinsky signs may be positive, and vibration and position sensitivity often decreases. Behavoural disorders range from irritability and memory loss to severe dementia. The symptoms often do not fully respond to treatment. A case is presented of an isolated vitamin B12 deficiency in 27 year-old female patient who was seen in primary health care. During anamnesis she mentioned low back pain, to which she attributed the loss of strength and tenderness in the right side of the body, as well as the slow and progressive onset of accompanied headache for the previous 4 days. PMID:23834987

Martinez Estrada, K M; Cadabal Rodriguez, T; Miguens Blanco, I; García Méndez, L

2012-08-11

139

How prevalent is vitamin B(12) deficiency among vegetarians?  

PubMed

Vegetarians are at risk for vitamin B(12) (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. The deficiency rates reported for specific populations were as follows: 62% among pregnant women, between 25% and almost 86% among children, 21-41% among adolescents, and 11-90% among the elderly. Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12. PMID:23356638

Pawlak, Roman; Parrott, Scott James; Raj, Sudha; Cullum-Dugan, Diana; Lucus, Debbie

2013-01-02

140

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.

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

2011-01-01

141

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.

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

2012-01-01

142

Folate and vitamin B12 in idiopathic male infertility  

PubMed Central

Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether idiopathic male infertility is associated with variants in folate, vitamin B12 (B12) and total homocysteine (tHcy)-related genes and measured these metabolites in blood. We conducted a case–control study that included 153 men with idiopathic infertility and 184 fertile male controls recruited at the Fertility Center and Antenatal Care Center, University Hospital, Malmö and Lund, Sweden. Serum folate, red cell folate (RCF), serum B12, plasma tHcy and semen quality were measured. Subjects were genotyped for 20 common variants in 12 genes related to folate/B12/homocysteine metabolism. Metabolite concentrations and genotype distributions were compared between cases and controls using linear and logistic regression with adjustment for covariates. The phosphatidylethanolamine N-methyltransferase (PEMT) M175V and TCblR rs173665 polymorphisms were significantly associated with infertility (P=0.01 and P=0.009, respectively), but not with semen quality. Among non-users of supplements, infertile men had lower serum folate concentrations than fertile men (12.89 vs. 14.73 nmol l?1; P=0.02), but there were no significant differences in RCF, B12 or tHcy. Folate, B12 and tHcy concentrations were not correlated with any semen parameters. This study provides little support for low folate or B12 status in the pathogenesis of idiopathic male infertility. Although additional data are needed to confirm these initial findings, our results suggest that PEMT and TCblR, genes involved in choline and B12 metabolism, merit further investigation in idiopathic male infertility.

Murphy, Laurel E; Mills, James L; Molloy, Anne M; Qian, Cong; Carter, Tonia C; Strevens, Helena; Wide-Swensson, Dag; Giwercman, Aleksander; Levine, Richard J

2011-01-01

143

Vitamin B12 in neurology and ageing; clinical and genetic aspects.  

PubMed

The classic neurological and psychiatric features associated with vitamin B12 deficiency have been well described and are the subject of many excellent review articles. The advent of sensitive diagnostic tests, including homocysteine and methylmalonic acid assays, has revealed a surprisingly high prevalence of a more subtle 'subclinical' form of B12 deficiency, particularly within the elderly. This is often associated with cognitive impairment and dementia, including Alzheimer's disease. Metabolic evidence of B12 deficiency is also reported in association with other neurodegenerative disorders including vascular dementia, Parkinson's disease and multiple sclerosis. These conditions are all associated with chronic neuro-inflammation and oxidative stress. It is possible that these clinical associations reflect compromised vitamin B12 metabolism due to such stress. Physicians are also increasingly aware of considerable inter-individual variation in the clinical response to B12 replacement therapy. Further research is needed to determine to what extent this is attributable to genetic determinants of vitamin B12 absorption, distribution and cellular uptake. PMID:23228515

McCaddon, Andrew

2012-12-07

144

Vitamin B12 replacement therapy: how much is enough?  

PubMed

Vitamin B12 deficiency becomes increasingly common with advancing age. Diverse recommendations exist for initial and maintenance therapy of deficiency states. With cyanocobalamin, the only B12 preparation available in the United States, much greater amounts of the vitamin are retained with a 1000 micrograms injection than with 100 micrograms, with no disadvantage in cost or toxicity. Maintenance therapy using the larger dosage may be necessary to meet metabolic requirements in many patients. Thus, it is recommended that parenteral regimens use 1000 micrograms cyanocobalamin: 5 or 6 biweekly injections for loading, and once-a-month for maintenance. Oral therapy with 300-1000 micrograms per day may be therapeutically equivalent to parenteral therapy. PMID:8053222

Watts, D T

1994-05-01

145

Cobalamin and Folate Evaluation: Measurement of Methylmalonic Acid and Homocysteine vs Vitamin B12 and Folate  

Microsoft Academic Search

Vitamin B12 and folate are two vitamins that have interdependent roles in nucleic acid synthesis. Deficien- cies of either vitamin can cause megaloblastic anemia; however, inappropriate treatment of B12 deficiency with folate can cause irreversible nerve degeneration. Inade- quate folate nutrition during early pregnancy can cause neural tube defects in the developing fetus. In addition, folate and vitamin B12 deficiency

George G. Klee

2000-01-01

146

Vitamin B12 as a Growth Factor for Soil Bacteria  

Microsoft Academic Search

STUDIES of the nutritional requirements of soil bacteria isolated on a non-selective basis1 have shown the presence of a well-defined group of organisms dependent upon soil extract for maximum growth. These bacteria show no growth, or at best sub-maximal growth, in media containing sugars and inorganic salts, supplemented by yeast extract or combinations of amino-acids and vitamins (not including B12).

A. G. Lochhead; R. H. Thexton

1951-01-01

147

Vitamin B12Responsive Pancytopenia Mimicking Myelodysplastic Syndrome  

Microsoft Academic Search

This study presents 12 patients (7 women and 5 men) with vitamin B12-responsive pancytopenia who had discordant laboratory findings and were misdiagnosed as having myelodysplastic syndrome (MDS). The median hemoglobin level was 6.5 g\\/dl, and the leukocyte and platelet counts were 2.85 × 109\\/l and 55.5 × 109\\/l, respectively. The median serum lactate dehydrogenase level was high (3,204.5 IU\\/l). The

Myungshin Kim; Sung-Eun Lee; Jihyang Lim; Byung-Sik Cho; Yoo-Jin Kim; Hee-Je Kim; Seok Lee; Chang-Ki Min; Yonggoo Kim; Seok-Goo Cho

2011-01-01

148

Vitamin B12 deficiency among patients with diabetes mellitus: is routine screening and supplementation justified?  

PubMed Central

Vitamin B12 is an essential micronutrient required for optimal hemopoetic, neuro-cognitive and cardiovascular function. Biochemical and clinical vitamin B12 deficiency has been demonstrated to be highly prevalent among patients with type 1 and type 2 diabetes mellitus. It presents with diverse clinical manifestations ranging from impaired memory, dementia, delirium, peripheral neuropathy, sub acute combined degeneration of the spinal cord, megaloblastic anemia and pancytopenia. This review article offers a current perspective on the physiological roles of vitamin B12, proposed pathophysiological mechanisms of vitamin B12 deficiency, screening for vitamin B12 deficiency and vitamin B12 supplementation among patients with diabetes mellitus.

2013-01-01

149

Vitamin B12 deficiency among patients with diabetes mellitus: is routine screening and supplementation justified?  

PubMed

Vitamin B12 is an essential micronutrient required for optimal hemopoetic, neuro-cognitive and cardiovascular function. Biochemical and clinical vitamin B12 deficiency has been demonstrated to be highly prevalent among patients with type 1 and type 2 diabetes mellitus. It presents with diverse clinical manifestations ranging from impaired memory, dementia, delirium, peripheral neuropathy, sub acute combined degeneration of the spinal cord, megaloblastic anemia and pancytopenia. This review article offers a current perspective on the physiological roles of vitamin B12, proposed pathophysiological mechanisms of vitamin B12 deficiency, screening for vitamin B12 deficiency and vitamin B12 supplementation among patients with diabetes mellitus. PMID:23651730

Kibirige, Davis; Mwebaze, Raymond

2013-05-07

150

[Stability of folic acid and vitamin B12 in TPN].  

PubMed

The stability of folic acid (FA) in mixtures of Total Parenteral Nutrition has been and is a controversial subject, with discussion concerning the influence of factors such as temperature, light and storage time. As regards the stability of the vitamin B12, there are few studies in scientific literature. For all those reasons, we consider it necessary to make a proper study to evaluate the influence of different factors in the stability of both vitamins. The study was made on 3 liter TPN bags of the EVA type, the composition of which was as follows: AA (85g), glucosa (225g), fat (50g), Na (86mEq), K (60 mEq), Ca (15 mEq), Cl (90 mEq), P (17 mmol) acetate (149 mEq) and 10 ml of MVI-12 which contain 400 micrograms of PA and 5 micrograms of Vitamin B 12. Consideration was also given to the stability of these two vitamins in the same diet, to which were added 10 ml of a commercial preparation of oligo-elements. Six TPN bags were prepared (without oligo-elements); two of them were kept in a fridge and protected from the light, two were kept at room temperature and protected from the light and the other two at room temperature without protection from the light. Samples were taken from all the bags immediately after their preparation and after 24, 48, 72 and 96 hours. The same process was carried with other TPN bags which did contain oligo-elements. The method for determining FA and Vitamin B12 was by radioassay.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1764534

Almodóvar, M J; Hernández Jaras, M V; León-Sanz, M; Ortuño, B; Estenoz, J; Negro Vega, E; Marfagón, N; Herreros de Tejada, A

151

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...

152

Diversity in rat tissue accumulation of vitamin B12 supports a distinct role for the kidney in vitamin B12 homeostasis  

Microsoft Academic Search

Background. Vitamin B12 in plasma is complexed to the carrier proteins transcobalamin (TC) and hapto- corrin. The TC-B12 complex is filtered in the glomeruli and reabsorbed in the renal tubules by receptor- mediated endocytosis, providing a route for a signi- ficant renal accumulation of vitamin B12. The present study investigates the role of the rodent kidney in B12 homeostasis by

Henrik Birn; Ebba Nexø; Erik Ilsø Christensen; Rikke Nielsen

153

Negative symptoms presenting as neuropsychiatric manifestation of vitamin B12 deficiency  

PubMed Central

Long lists of psychiatric illness or symptoms have been documented to be caused by vitamin B12 deficiency. We describe an atypical case of a young adult who presented with predominant negative symptoms followed by neurological symptoms consistent with vitamin B12 deficiency. The symptoms showed complete remission after vitamin B12 supplementation. The uniqueness of this case is that vitamin B12 deficiency presented with predominant negative symptoms without other psychotic and manic symptoms, which has not been reported previously.

Sahoo, Manoj Kumar; Avasthi, Ajit; Singh, Parampreet

2011-01-01

154

Vitamin B12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia  

Microsoft Academic Search

Background: Vegetarians have a lower intake of vitamin B-12 than do omnivores. Early and reliable diagnosis of vitamin B-12 deficiency is very important. Objective: The objective was to investigate vitamin B-12 status in vegetarians and nonvegetarians. Design: The study cohort included 66 lactovegetarians or lac- toovovegetarians (LV-LOV group), 29 vegans, and 79 omnivores. Total vitamin B-12, methylmalonic acid, holotranscobalamin II,

Wolfgang Herrmann; Heike Schorr; Rima Obeid; Jürgen Geisel

155

Dose-response effects of long-acting injectable vitamin B12 plus selenium (Se) on the vitamin B12 and Se status of ewes and their lambs  

Microsoft Academic Search

AIM: To determine the effect of increasing doses of long-acting injectable vitamin B12 plus selenium (Se) given pre-mating on the vitamin B12 and Se status of ewes and their lambs from birth to weaning.METHODS: Four groups of 24 Poll Dorset ewes each were injected 4 weeks pre-mating with different doses of a long-acting vitamin B12 + Se product, containing 3

ND Grace; SO Knowles

2006-01-01

156

Vitamin B12 deficiency presenting as acute ataxia.  

PubMed

A previously healthy 7-year-old Caucasian boy was hospitalised for evaluation of acute ataxia and failure to thrive, initially suspicious for an intracranial mass. Weight and body mass index were below the third percentile and he demonstrated loss of joint position and vibratory sense on examination. Laboratory studies revealed megaloblastic anaemia while an initial MRI of the brain showed no evidence of mass lesions or other abnormalities. A dietary history revealed the child subscribed to a restrictive vegan diet with little to no intake of animal products or other fortified foods. The child was diagnosed with presumed vitamin B12 deficiency and was treated with intramuscular B12 injections. Neurological symptoms resolved promptly within several days after starting therapy. This case underlines the importance of assessing nutritional status in the evaluation of neurological dysfunction in the pediatric patient. PMID:23536622

Crawford, John Ross; Say, Daphne

2013-03-26

157

High frequency of maternal vitamin B 12 deficiency as an important cause of infantile vitamin B 12 deficiency in Sanliurfa province of Turkey  

Microsoft Academic Search

Summary\\u000a Background  Vitamin B12 deficiency in infancy may cause failure to thrive, severe neurological disorders and megaloblastic pancytopenia. It is well\\u000a known that infants born with deficient vitamin B12 storage have increased the risk of vitamin B12 deficiency. Vitamin B12 deficiency is more prevalent in infancy in Sanliurfa province (at the southeast region of Turkey).\\u000a \\u000a \\u000a \\u000a Aim of the study  The aim of

Ahmet Koc; Abdurrahim Kocyigit; Mustafa Soran; Nihat Demir; Eylem Sevinc; Ozcan Erel; Zeki Mil

2006-01-01

158

Dietary source of vitamin B12 intake and vitamin B12 status in female elderly Koreans aged 85 and older living in rural area  

PubMed Central

Recently, we found and analyzed vitamin B12 in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B12 intake and its dietary sources and the vitamin B12 status in the very old elderly Koreans. We measured serum vitamin B12 level and estimated the amounts of vitamin B12 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 B12 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 B12 intake of our subjects was 3.2 µg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 µg/day. On dietary source, 67.3% of dietary vitamin B12 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 B12 concentration was 450.5 pg/mL, and low serum vitamin B12 (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B12 intake was significantly lower in subjects with low serum vitamin B12 (0.79 µg/day) than those with normal serum vitamin B12 (3.47 µg/day). There were no significant difference in vitamin B12 intake and its dietary sources and serum vitamin B12 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 B12 status in very old elderly Koreans.

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

2010-01-01

159

Vitamin B12 deficiency in the aged: a population-based study  

Microsoft Academic Search

Background: vitamin B12 deficiency is common in the aged, but it is controversial whether only some risk groups should be investigated instead of screening the entire aged population. Objectives: to describe the prevalence of vitamin B12 deficiency in the Finnish aged, and to find out if the subjects especially prone to vitamin B12 deficiency could be identified by the risk

SAILA LOIKAS; P ERTTI KOSKINEN; K ERTTU IRJALA; R AIMO ISOAHO; S IRKKA-LIISA KIVEL; T ARJA-TERTTU PELLINIEMI

2006-01-01

160

VOLATILE FATTY-ACID CLEARANCE STUDIES IN RELATION TO VITAMIN B12 DEFICIENCY IN SHEEP  

Microsoft Academic Search

Clearance studies were used to investigate propionate and acetate metabolism in sheep at progressive stages during the induction of vitamin B12 (cobalt) deficiency. Both propionate and acetate clearance rates were increasingly adversely affected as vitamin B12 deficiency intensified. The effect of vitamin B12 on propionate and acetate clearance times was greater than the effect of depressed feed intake. Both of

M Somers

1969-01-01

161

Effect of Vitamin B12 Deficiency on Liver Dehydrogenase Activity in Rats  

Microsoft Academic Search

WEANLING rats born of mothers maintained on a diet deficient in vitamin B12 during pregnancy were fed on a vitamin B12-free ration for twelve weeks and their liver dehydrogenase levels were compared with those of similar animals receiving 2-µgm. supplements of vitamin B12 daily. The basal diet had the composition : whole soya bean flour, 25; groundnut cake flour, 14;

V. Sreenivasa Murthy; H. S. R. Desikachar; M. Swaminathan

1956-01-01

162

Dementia and subnormal levels of vitamin B 12 : Effects of replacement therapy on dementia  

Microsoft Academic Search

Routine determination of serum vitamin B12 levels is generally recommended as part of the screening of demented patients, based on the notion that vitamin B12 deficiency is one of the causes of reversible dementia. We studied the effects of vitamin B12 replacement therapy in a prospective longitudinal study at a memory clinic, with special emphasis on assessment of severity of

Saskia Teunisse; Anna E. Bollen; Willem A. van Gool; Gerard J. M. Walstra

1996-01-01

163

Use of vitamin B12 conjugates to deliver protein drugs by the oral route.  

PubMed

The treatment of patients with most peptide and protein pharmaceuticals must currently be performed by injection, with the accompanying disadvantages of patient discomfort, increased medical costs, and reduced patient compliance. It would be much easier and more acceptable if these drugs could be given by the oral route. Unfortunately, this route cannot be used with most proteins and with peptides due to both the degradation of these molecules within the intestine and their poor uptake across the intestinal wall. In this review, an uptake system is described that potentially overcomes both these problems. This system relies upon the natural uptake mechanism for vitamin B12 to cotransport peptides and proteins linked to the vitamin B12 from the intestine to the circulation. In an exciting extension to this technology, it has been found that it is also possible to transport nanoparticles, linked to the vitamin B12, into the circulation. Such nanoparticles can potentially be loaded with peptides or proteins of choice, and so protect these molecules from degradation in the intestine, while simultaneously transporting them into the circulation. These findings are an important step in realizing the possibility of delivering almost all peptides and proteins via the oral route. PMID:9883390

Russell-Jones, G J

1998-01-01

164

Metabolites of Vitamin B12 in Bile after Parenteral Administration of the Vitamin  

Microsoft Academic Search

SEVERAL investigations have shown that, in animals and in man1, the major proportion of the total radioactivity excreted after an injection of radioactive vitamin B12 is excreted in the bile, and that in man at least two-thirds of the biliary radioactivity is re-absorbed from the intestine. This indicates that vitamin B12 is subject to an entero-hepatic circulation similar to other

John B. Stokes

1961-01-01

165

Biologically active vitamin B12 compounds in foods for preventing deficiency among vegetarians and elderly subjects.  

PubMed

The usual dietary sources of vitamin B12 are animal-source based foods, including meat, milk, eggs, fish, and shellfish, although a few plant-based foods such as certain types of dried lavers (nori) and mushrooms contain substantial and considerable amounts of vitamin B12, respectively. Unexpectedly, detailed characterization of vitamin B12 compounds in foods reveals the presence of various corrinoids that are inactive in humans. The majority of edible blue-green algae (cyanobacteria) and certain edible shellfish predominately contain an inactive corrinoid known as pseudovitamin B12. Various factors affect the bioactivity of vitamin B12 in foods. For example, vitamin B12 is partially degraded and loses its biological activity during cooking and storage of foods. The intrinsic factor-mediated gastrointestinal absorption system in humans has evolved to selectively absorb active vitamin B12 from naturally occurring vitamin B12 compounds, including its degradation products and inactive corrinoids that are present in daily meal foods. The objective of this review is to present up-to-date information on various factors that can affect the bioactivity of vitamin B12 in foods. To prevent vitamin B12 deficiency in high-risk populations such as vegetarians and elderly subjects, it is necessary to identify plant-source foods that contain high levels of bioactive vitamin B12 and, in conjunction, to prepare the use of crystalline vitamin B12-fortified foods. PMID:23782218

Watanabe, Fumio; Yabuta, Yukinori; Tanioka, Yuri; Bito, Tomohiro

2013-07-02

166

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

PubMed

A high prevalence of low serum vitamin B-12 concentrations has been reported in studies and surveys in Latin America including Mexico, but the functional consequences are unknown. This randomized controlled trial assessed the response to a high-dose vitamin B-12 supplementation of women in rural Querétaro, Mexico. Participants aged 20-59 y were stratified at baseline to deficient, marginal, and adequate status groups (serum vitamin B-12, 75-148, 149-220, and >220 pmol/L, respectively), and each group was randomized to vitamin B-12 treatment (single dose of 1 mg i.m. then 500 ?g/d orally for 3 mo, n = 70) or placebo (n = 62). Measures at baseline and 3 mo included: complete blood count, serum vitamin B-12, holotranscobalamin (holoTC), folate, ferritin, C-reactive protein (CRP), bone alkaline phosphatase, and methylmalonic acid (MMA) and plasma total homocysteine (tHcy). At baseline, 11% of the women were vitamin B-12 deficient and 22% had marginal status. HoloTC was low (<35 pmol/L) in 23% and correlated with serum vitamin B-12 (r = 0.7; P < 0.001). Elevated MMA (>271 nmol/L) and tHcy (>12 ?mol/L) occurred in 21 and 31%, respectively, and correlated with serum vitamin B-12 (r = -0.28, P < 0.0007 and r = -0.20, P < 0.01, respectively). Supplementation increased serum vitamin B-12 and holoTC and lowered MMA and tHcy, normalizing all values except for elevated tHcy in 21% of the women. Supplementation did not affect hematology or bone-specific alkaline phosphatase. Vitamin B-12 supplementation normalized biochemical indicators of vitamin B-12 status in the treatment group but did not affect the functional outcomes measured. PMID:22915298

Shahab-Ferdows, Setareh; Anaya-Loyola, Miriam A; Vergara-Castañeda, Haydé; Rosado, Jorge L; Keyes, William R; Newman, John W; Miller, Joshua W; Allen, Lindsay H

2012-08-22

167

Vitamin B12 Deficiency Due to a Strictly Vegetarian Diet in Adolescence  

Microsoft Academic Search

A 14-year-old white girl suffered from severe neurologic disturbances caused by vitamin B12 deficiency, due to failure to provide vitamin B12 supplementation to a strictly vegetarian diet. The disturbances resolved completely following treatment with vatamin B12. Physicians should be alert to the necessity for vitamin B12 supplementation for strict vegetarians, who eat no meat, fish, eggs, or dairy products.

S. Ashkenazi; R. Weitz; I. Varsano; M. Mimouni

1987-01-01

168

An evaluation of the efficacy of injectable microencapsulated Vitamin B12 in increasing and maintaining the serum and liver Vitamin B12 concentrations of lambs  

Microsoft Academic Search

Aim. To develop a long-acting vitamin B, injection to prevent Co deficiency in sheep.Methods. Formulations of microencapsulated Vitamin B12 in lactide-glycolide polymers were injected intramuscularly or subcutaneously into the anterior neck region of groups of 10 lambs and their efficacy determined from changes in serum and liver Vitamin B12 concentrations.Results. The 955 lactide glycolide and the 100 lactide formulations containing

N. D. Grace; D. H. Lewis

1999-01-01

169

Maximal Load of the Vitamin B12 Transport System: A Study on Mice Treated for Four Weeks with High-Dose Vitamin B12 or Cobinamide  

PubMed Central

Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n?=?7 in each group). B12 content and markers of B12 metabolism were analysed in plasma, urine, kidney, liver, and salivary glands. Both Cbi and B12 treatment saturated the transcobalamin protein in mouse plasma. Cbi decreased the content of B12 in tissues to 33–50% of the level in control animals but did not influence any of the markers examined. B12 treatment increased the tissue B12 level up to 350%. In addition, the transcript levels for methylenetetrahydrofolate reductase in kidneys and for transcobalamin and transcobalamin receptor in the salivary glands were reduced. Our study confirms the feasibility of delivering drugs through the B12 transport system but emphasises that B12 status should be monitored because there is a risk of decreasing the transport of endogenous B12. This risk may lead to B12 deficiency during prolonged treatment.

Lildballe, Dorte L.; Mutti, Elena; Birn, Henrik; Nexo, Ebba

2012-01-01

170

Maximal load of the vitamin B12 transport system: a study on mice treated for four weeks with high-dose vitamin B12 or cobinamide.  

PubMed

Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n = 7 in each group). B12 content and markers of B12 metabolism were analysed in plasma, urine, kidney, liver, and salivary glands. Both Cbi and B12 treatment saturated the transcobalamin protein in mouse plasma. Cbi decreased the content of B12 in tissues to 33-50% of the level in control animals but did not influence any of the markers examined. B12 treatment increased the tissue B12 level up to 350%. In addition, the transcript levels for methylenetetrahydrofolate reductase in kidneys and for transcobalamin and transcobalamin receptor in the salivary glands were reduced. Our study confirms the feasibility of delivering drugs through the B12 transport system but emphasises that B12 status should be monitored because there is a risk of decreasing the transport of endogenous B12. This risk may lead to B12 deficiency during prolonged treatment. PMID:23049711

Lildballe, Dorte L; Mutti, Elena; Birn, Henrik; Nexo, Ebba

2012-10-01

171

FUETHEE STUDIES ON THE ABSOEPTION OF VITAMIN B12 FOLLOWING OEAL AND PAEENTEEAL ADMINISTEATION >•2  

Microsoft Academic Search

Vitamin B12 appears to be an essential nutritional factor, administration of which may overcome the manifestations of pernicious anemia. Evidences available at this time suggest that in patients with this disease there is impaired absorption of vitamin B12 from the gastrointestinal tract. Oral adminis tration of this vitamin in amounts equivalent to many times the minimum effective parenteral dose is

R. YAMAMOTO; CHARLES BARROWS; CALVIN LANG

2010-01-01

172

Effect of vitamin B12 and folic acid deficiency on small intestinal absorption  

PubMed Central

Three patients are described, and they provide further evidence that deficiency of folic acid and vitamin B12 may sometimes affect small intestinal function. Malabsorption of both xylose and vitamin B12 returned to normal in one patient after treatment of a megaloblastic anaemia due to dietary deficiency of folic acid. Impaired absorption of vitamin B12 was corrected by vitamin B12 therapy in the other two patients. The initial cause of the vitamin B12 deficiency in one patient was not apparent, but she was taking Gynovlar 21, which may have been an aetiological factor. In the third patient the small intestinal defect was secondary to pernicious anaemia, and in a group of 98 other patients with pernicious anaemia intrinsic factor did not improve vitamin B12 absorption in six, and only partially corrected absorption in 30. The significance of these observations is discussed.

Forshaw, John

1969-01-01

173

[Neurological picture and selected diagnostic indices of vitamin b12 malabsorption syndrome].  

PubMed

Funicular myelosis is considered to be the main neurological syndrome in vitamin B12 deficiency. However, many authors tend to think that sensory neuropathy is the most common neurological manifestation of vitamin B12 deficiency. The aim of this paper was to assess neurological condition of patients with vitamin B12 malabsorption. The absorption of vitamin B-12 was assessed by Schilling's test. Patients with abnormal results of this test underwent neurological and medical examinations as well as series of accessory investigations. 16 cases of deficient vitamin B12 absorption accompanied by neurological symptoms were presented. The results of the investigation showed that the most common clinical manifestation of vitamin B12 deficiency was sensory neuropathy. In over 93% of described cases pathologic changes in gastric mucous membrane were found. PMID:11556213

Tomczyk, A; Helewski, K; G?owacka, M; Konecki, J; Stepie?, M

2001-01-01

174

Screening for vitamin B12 and folate deficiency in older persons1-3  

Microsoft Academic Search

Background: Vitamin B-12 deficiency is usually accompanied by elevated concentrations of serum total homocysteine (tHcy) and methylmalonic acid (MMA). Folate deficiency also results in ele- vated tHcy. Measurement of these metabolites can be used to screen for functional vitamin B-12 or folate deficiency. Objective: We assessed the prevalence of vitamin B-12 and folate deficiency in a population-based study (n =

Robert Clarke; Helga Refsum; Jacqueline Birks; John Grimley Evans; Carole Johnston; Paul Sherliker; Joern Schneede; Joseph McPartlin; Ebba Nexo; John M Scott

175

Vitamin B12 antagonism by monocarboxylic acids and anilides of cyanocobalamin  

Microsoft Academic Search

VARIOUS test systems have been used to examine the anti-metabolite activity of vitamin B12 analogues1. In general, the tests have relied on the demonstration of growth inhibition or depression in either vitamin B12-requiring microorganisms or vitamin B12-deficient experimental animals. I have investigated the effect of the mixed isomeric monocarboxylic acids of cyanocobalamin and the anilides derived from these acids on

R. C. Siddons

1974-01-01

176

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

PubMed

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

Yetley, Elizabeth A; 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; Coates, Paul M; Johnson, Clifford L; Picciano, Mary Frances

2011-05-18

177

Persistence of neurological damage induced by dietary vitamin B12 deficiency in infancy  

Microsoft Academic Search

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

Ursula von Schenck; Christine Bender-Götze; Berthold Koletzko

1997-01-01

178

Reference curves to diagnose cobalt deficiency in sheep using liver and serum vitamin B12 levels  

Microsoft Academic Search

Reference curves demonstrating the relationship between serum or liver vitamin B12 and weight gain were derived from the examination of 16 published and 48 unpublished N.Z. trials. From these curves probability of obtaining an economic reponse (>10g\\/day body weight increase) for any serum or liver vitamin B12 can be determined. No significant (P<0.05) weight gain responses occurred to vitamin B12

R. G. Clark; D. F. Wright; K. R. Millar; J. D. Rowland

1989-01-01

179

Treatment responsive executive and behavioral dysfunction associated with Vitamin B12 deficiency  

Microsoft Academic Search

Vitamin B12 deficiency can manifest with various neuropsychiatric symptoms. We report a case of an individual with vitamin B12 deficiency presenting with personality, emotional and behavioral changes. Neuropsychological tests revealed disproportionate disturbance of executive functions. Single photon emission tomography (Tc99m HMPAO) showed right fronto-temporo-parietal hypoperfusion. After vitamin B12 injections, the patient's executive and behavioral dysfunction disappeared and performance on neuropsychological

Gülden Akdal; Görsev G. Yener; Pinar Kurt

2008-01-01

180

The diagnosis and treatment of vitamin B12 deficiency in young lambs  

Microsoft Academic Search

ExtractIn the course of some earlier experiments, it was observed that vitamin B12 deficiency in 2 hoggets was corrected by injection of hydroxocobalamin (vitamin B12b) (E. D. Andrews, pers. comm., 1972). Since this form of therapy offered a convenient and effective means of treating young lambs suffering from vitamin B12 deficiency, more detailed investigations were desirable. It has been known

K. G. Hogan; P. P. Lorentz; F. M. Gibb

1973-01-01

181

Economic and laboratory considerations in screening for vitamin B12 deficiency in psychiatric practice.  

PubMed

Two alternative methods for detecting vitamin B(12) deficiency in a psychiatric population have been compared: the ;direct' approach by microbiological assay of serum vitamin B(12) levels in all patients, and the ;indirect' approach where all patients are first screened for antigastric parietal cell antibodies and thereafter all positive reactors and other ;high-risk' patients have serum vitamin B(12) assayed. The indirect approach was found to be cheaper. PMID:4891481

Beck, J S; Dawson, A A; Henderson, J G; Strachan, R W

1969-05-01

182

Vitamin B-12 deficiency is prevalent in 35- to 64-year-old Chinese adults.  

PubMed

Low vitamin B-12 status alone, or in combination with low folate status, is related to neural tube defects (NTD) and hyperhomocysteinemia, a risk factor for atherosclerotic disease, but little is known about vitamin B-12 status in Chinese adults. In a cross-sectional study, we measured plasma vitamin B-12 in 2407 apparently healthy Chinese men and women, 35-64 y old, living in the south and the north of China. Plasma vitamin B-12 concentrations were lower among the northerners than the southerners (geometric means, 209 vs. 309 pmol/L, P < 0.001). Controlling for gender, age, season (spring and fall), and area (urban and rural) had little impact on the difference. We estimated that 11% of the southerners and 39% of the northerners had plasma vitamin B-12 concentrations <185 pmol/L, a level to define vitamin B-12 deficiency. Within each region, men had lower plasma vitamin B-12 concentrations and higher prevalence of vitamin B-12 deficiency than women (279 vs. 333 pmol/L and 15 vs. 8% in the south; 192 vs. 233 pmol/L and 47 vs. 34% in the north; P < 0.001 for all the differences). Low intakes of animal-based food, especially fish and dairy products, were significantly associated with vitamin B-12 deficiency. In the north, 59% of the participants were deficient in either folate (<6.8 nmol/L) or vitamin B-12, and 17% had deficiency in both. The corresponding rates were 16 and 1% in the southerners. To our knowledge, our findings provide the first evidence that vitamin B-12 deficiency is common in 35- to 64-y-old Chinese adults, especially in the north. Further studies are needed to evaluate the health effects and possible intervention strategies in areas where B-12 vitamin deficiency is common. PMID:17449593

Hao, Ling; Ma, Jing; Zhu, Jianghui; Stampfer, Meir J; Tian, Yihua; Willett, Walter C; Li, Zhu

2007-05-01

183

Effects of vitamin B12, folate, and vitamin B6 supplements in elderly people with normal serum vitamin concentrations  

Microsoft Academic Search

SummaryIn a prospective, multicentre, double-blind controlled study, the effect of an intramuscular vitamin supplement containing 1 mg vitamin B12, 1·1 mg folate, and 5 mg vitamin B6 on serum concentrations of methylmalonic acid (MMA), homocysteine (HCYS), 2-methylcitric acid (2-MCA), and cystathionine (CYSTA) was compared with that of placebo in 175 elderly subjects living at home and 110 in hospital. Vitamin

H. J. Naurath; E. Joosten; R. Riezler; S. Stabler; R. H. Allen; J. Lindenbaum

1995-01-01

184

Nutritional vitamin B12 deficiency: two cases detected by routine newborn urinary screening.  

PubMed

We describe two asymptomatic newborns with nutritional vitamin B12 deficiency in whom increased urinary methylmalonic acid was detected by routine neonatal screening at 3 weeks of age. Both infants were exclusively breast-fed. One mother suffered from pernicious anaemia, and the other was a strict vegetarian. Both mothers had no clinical or haematological abnormality, aside from a borderline mean corpuscular volume for the vegetarian mother. This report illustrates the early appearance of functional vitamin B12 deficiency in breast-fed infants of vitamin B12-depleted mothers. It also demonstrates that urinary methylmalonic acid measurement is a sensitive indicator of tissue vitamin B12 deficiency. PMID:1601016

Michaud, J L; Lemieux, B; Ogier, H; Lambert, M A

1992-03-01

185

Addisonian pigmentation and vitamin B12 deficiency: a case series and review of the literature.  

PubMed

Skin changes associated with vitamin B12 deficiency are common. In most cases, patients present primarily with systemic involvement (eg, megaloblastic anemia and/or neurologic effects), and additional cutaneous changes related to the diagnosis are noted as incidental findings. The role of vitamin B12 deficiency in the etiology of Addisonian pigmentation has not been well studied. We discuss the importance of testing vitamin B12 levels in patients who present for evaluation of generalized hyperpigmentation. Various cutaneous changes associated with vitamin B12 deficiency also are reviewed. PMID:24087784

Jithendriya, Madhukara; Kumaran, Sendhil; P, Ishwara B

2013-08-01

186

Detection of protein bound vitamin B12 malabsorption. A case report and review of the literature.  

PubMed

The Schilling test is used to identify the cause of vitamin B12 malabsorption in patients with low serum vitamin B12 levels. The initial step required for vitamin B12 absorption is a process of separation from the protein complexes of food. The crystalline Co-57 vitamin B12 used in the Schilling test does not reproduce this physiologic process. Thus, a crystalline stage I Schilling test may be normal even in the face of cobalamin malabsorption. An adjunctive stage I Schilling test using Co-57 vitamin B12 bound to protein has been developed. The authors describe a patient with protein-bound vitamin B12 malabsorption whose crystalline Co-57 vitamin B12 stage I Schilling test was normal. A subsequent stage I Schilling test using Co-57 vitamin B12 bound to chicken serum revealed significant cobalamin malabsorption. A review of the history and literature of this diagnostic test using protein bound vitamin B12 is also presented. PMID:7842570

Lucas, M H; Elgazzar, A H

1994-11-01

187

FOLATE, VITAMIN B12 AND VITAMIN B6 AND ONE CARBON METABOLISM  

Technology Transfer Automated Retrieval System (TEKTRAN)

The vitamins folic acid, B12 and B6 and B2 are the source of coenzymes which participate in one carbon metabolism. In this metabolism, a carbon unit from serine or glycine is transferred to tetrahydrofolate (THF) to form methylene-THF. This is either used as such for the synthesis of thymidine, whic...

188

Growth response to increasing doses of microencapsulated vitamin B12 and related changes in tissue vitamin B12 concentrations in cobalt-de cient lambs  

Microsoft Academic Search

AIM: To investigate growth responses of cobalt-deficient lambs to increasing doses of microencapsulated vitamin B12, and to measure associated changes in serum and liver vitamin B12 concentrations over 243 days.METHODS: From a flock grazing pastures that had low cobalt (Co) levels (about 0.06 mg Co\\/kg dry matter), 4-6-week-old lambs (n=137) were assigned to four groups and received either no treatment

ND Grace; SO Knowles; GR Sinclair; J Lee

2003-01-01

189

Laboratory Evaluation for Vitamin B12 Deficiency: The Case for Cascade Testing  

PubMed Central

Objective Potential vitamin B12 deficiency is a common clinical diagnostic problem, and many providers have a low threshold for initiating therapy. The goal of this study was to systematically evaluate current practice patterns regarding the laboratory evaluation of suspected vitamin B12 deficiency. Methods This retrospective study reviewed the electronic medical records of 192 patients initiated on intramuscular vitamin B12 injections. Results Only 12 patients had objectively documented hematologic responses: decrease of mean corpuscular volume by ?5 fL with stable or improved hemoglobin. Another 5 patients had equivocal hematologic responses. There was one plausible neurologic response. Thus, only 18 (9.4%) of 192 patients had data supportive of a clinical response. In these 18 patients, the baseline serum B12 level was ?107 pg/mL; only 3 patients also had a baseline serum methylmalonic acid level, which was ?1.29 ?mol/L in all 3 patients. Conclusions Currently, only a small minority of patients initiated on intramuscular vitamin B12 supplementation derive any meaningful clinical benefit. Furthermore, current testing recommendations for vitamin B12 deficiency are usually not followed. Up-front ordering of a diagnostic testing cascade is recommended to improve compliance; an example is presented with decision points chosen to improve specificity for clinically evident vitamin B12 deficiency without loss of sensitivity. Ultimately, a better understanding of vitamin B12 physiology is needed to develop and evaluate laboratory tests that more accurately reflect true intracellular vitamin B12 status.

Berg, Richard L.; Shaw, Gene R.

2013-01-01

190

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

191

Effect of a Klamath algae product ("AFA-B12") on blood levels of vitamin B12 and homocysteine in vegan subjects: a pilot study.  

PubMed

Vitamin B12 is a critical nutrient that is often inadequate in a plant-based (vegan) diet, thus the inclusion of a reliable vitamin B12 source in a vegan diet is recommended as essential. Unfortunately, many natural sources of vitamin B12 have been proven to contain biologically inactive vitamin B12 analogues, inadequate for human supplementation. The aim of this non-randomized open trial was to determine whether supplementation with a natural Klamath algae-based product ("AFA-B12", Aphanizomenon flos-aquae algae plus a proprietary mix of enzymes) could favorably affect the vitamin B12 status of a group of 15 vegan subjects. By assessing blood concentration of vitamin B12, folate, and more importantly homocysteine (Hcy, a reliable marker in vegans of their B12 absorption), the vitamin B12 status of the participants at the end of the 3-month intervention period, while receiving the Klamath-algae supplement (T2), was compared with their vitamin B12 status at the end of the 3-month control period (T1), when they were not receiving any supplement, having stopped taking their usual vitamin B12 supplement at the beginning of the study (T0). Compared to the control period, in the intervention period participants improved their vitamin B12 status, significantly reducing Hcy blood concentration (p=0.003). In conclusion, the Klamath algae product AFA-B12 appears to be, in a preliminary study, an adequate and reliable source of vitamin B12 in humans. PMID:20108213

Baroni, Luciana; Scoglio, Stefano; Benedetti, Serena; Bonetto, Chiara; Pagliarani, Silvia; Benedetti, Yanina; Rocchi, Marco; Canestrari, Franco

2009-03-01

192

Malabsorption and deficiency of vitamin B12 in HIV-infected patients with chronic diarrhea.  

PubMed

Deficiency of vitamin B12 is commonly reported in HIV-infected patients. We measured vitamin B12 levels in 36 HIV-infected patients with chronic diarrhea (> 3 stools/day for six weeks or more). Eight patients had an identifiable cause of diarrhea. Vitamin B12 levels were low in 39%. Sixteen of these patients were selected to undergo further testing, eight patients with low levels of vitamin B12 and eight with normal B12 levels. These 16 patients had both a stage II Schilling test and measurement of multiple serum D-xylose concentrations performed after both oral and intravenous doses of D-xylose. Integrated areas under the curves (AUC) for D-xylose concentration versus time were calculated for intravenous and oral doses, and D-xylose bioavailability was determined. Stage II Schilling tests were abnormal in 11 patients, (69%). D-Xylose bioavailability correlated closely with vitamin B12 absorption (r = 0.648, P < 0.01). Comparisons of mean values for CD4 count, serum albumin, Karnovsky score, six-month weight loss, 1-hr serum D-xylose levels and MCV failed to reveal a significant difference between those with and without abnormal serum vitamin B12 levels. These data indicate that below-normal levels of vitamin B12 are highly prevalent in HIV-infected patients with chronic diarrhea. Malabsorption of vitamin B12 occurs in the setting of an enteropathic process effecting both the proximal and distal small bowel. Since no risk factors for vitamin B12 deficiency could be identified, screening for vitamin B12 deficiency in HIV-infected patients with chronic diarrhea is strongly recommended. PMID:7924736

Ehrenpreis, E D; Carlson, S J; Boorstein, H L; Craig, R M

1994-10-01

193

Vitamin B12 absorption test and oral treatment in 14 children with selective vitamin B12 malabsorption.  

PubMed

Oral vitamin B12 (VB12) absorption was studied in 12 patients with selective VB12 malabsorption and in 6 age-matched healthy controls. Serum VB12 level was measured before and 3 h after oral administration of VB12 100 or 1000 micrograms. After administration of 1000 micrograms of VB12 an appreciable increase in the serum VB12 level was observed in patients as well as in controls. The mean of the increase in the serum VB12 level did not differ between patients and the controls (273 +/- 203 pg/mL, 180 +/- 71 pg/mL, respectively P > .05). Twelve patients previously treated by parenteral VB12 were switched to, and 2 newly diagnosed patients were started on, oral VB12 treatment of 1000 micrograms given every 2 weeks. Hematological parameters and serum VB12 levels remained stable after switching to oral therapy in the 12 patients. In the two newly diagnosed patients anemia was cured by orally administrated VB12. This study lends further support to the use of megadoses of VB12 as an alternative treatment for selective VB12 malabsorption. PMID:10100276

Altay, C; Cetin, M

194

THE INFLUENCE OF VITAMIN B12 AND AUREOMYCIN SUPPLEMENTATION IN THE RATION ON THE VITAMIN B12 ACTIVITY OF PORK MUSCLE 1, 2  

Microsoft Academic Search

ONSIDERABLE research has been done to determine the effect of the animal protein factor (APF), vitamin B12, and aureomycin supplementation on the rate of gain and feed efficiency of swine. Luecke et al. (1949) reported that weanling pigs that were fed a corn and soybean diet, supplemented with 0.5 percent vitamin B~2 concen- trate, gained weight at a significantly greater

ROBERT F. KELLY; ROBERT W. BRAY; P. H. PHILLIPS

195

THE INFLUENCE OF DIET COMPOSITION ON VITAMIN B12 ACTIVITY IN MICE  

Microsoft Academic Search

Vitamin B12bas been shown to be an essential nutrient for several animal species as well as for several microorganisms. Very little is known about tbe role of vitamin B12 in metab olic processes, although it has been shown to be a potent anti- pernicious anemia factor in humans (\\

D. K. BOSSHARDT; WINIFRED J. PAUL; R. H. BARNES

196

Vitamin B12 levels in the livers of clinically normal cattle  

Microsoft Academic Search

ExtractAlthough the opinion has been expressed (Andrews, 1971) that cobalt deficiency among cattle has virtually disappeared in New Zealand and that specimens for laboratory examination are rarely required, 15 to 20% of the liver samples submitted by veterinarians to the Animal Health Reference Laboratory for vitamin B12 assay are from cattle. Diagnostic criteria for cobalt (vitamin B12) deficiency cy have

C. G. Rammell; W. S. H. Poole

1974-01-01

197

Interventions with vitamins B6, B12 and C in pregnancy  

Technology Transfer Automated Retrieval System (TEKTRAN)

The water-soluble vitamins B6, B12 and C play important roles in maternal health as well as fetal development and physiology during gestation. This systematic review evaluates the risks and benefits of interventions with vitamins B6, B12 and C during pregnancy on maternal, neonatal and child health ...

198

Hyperhomocysteinaemia and Vitamin B12 Deficiency: The Long-Term Effects in Cardiovascular Disease  

Microsoft Academic Search

Background: An elevated plasma homocysteine level is an established risk factor for cardiovascular disease. Vitamin B12 plays a key role in homocysteine metabolism and could be the main factor in causing cardiovascular disease as well. Objectives: The aim of this study was to assess whether vitamin B12 deficiency or hyperhomocysteinaemia is associated with recurrent cardiovascular events. Methods: Overall, 211 patients

Martijn G. H. van Oijen; Floor Vlemmix; Robert J. F. Laheij; Lea Paloheimo; Jan B. M. J. Jansen; Freek W. A. Verheugt

2007-01-01

199

Developmental Regression as an Early Manifestation of Vitamin B12 Deficiency  

Microsoft Academic Search

Loss of previously attained developmental milestones in an infant is often associated with central nervous system tumor, neuromuscular disease, or an inborn metabolic error. An infant with developmental regression and involuntary movements who was found to be vitamin B12 deficient on the basis of unrecognized maternal vitamin B12 deficiency is described. The infant had a dramatic neurologic recovery after receiving

P. David Sadowitz; Anne Livingston; Robert M. Cavanaugh

1986-01-01

200

Complications of dietary deficiency of Vitamin B12 in young Caucasians  

PubMed Central

The occurrence of dietary deficiency of Vitamin B12 is reported in two young caucasian adults. In one case megaloblastic anaemia occurred and in the other optic atrophy. The importance of the dietary history, the significance of folic acid intake and the inter-relationship of Vitamin B12 and cyanide detoxication are discussed.

Gleeson, M. H.; Graves, P. S.

1974-01-01

201

Recurrent aphthae: treatment with vitamin B12, folic acid, and iron  

Microsoft Academic Search

A series of 130 consecutive outpatients with recurrent aphthous stomatitis were screened at the oral medicine department, Glasgow Dental Hospital, for deficienciesin vitamin b12, folic acid, and iron. In 23 patients (17.7%) such deficiencies werefound; five were deficient in vitamin B12, seven in folic acid, and 15 in iron. Four had more than one deficiency. Out of 130 controls matched

D Wray; M M Ferguson; D K Mason; A W Hutcheon; J H Dagg

1975-01-01

202

Review of Health Aspects of Vitamin B12 as Food Ingredients.  

National Technical Information Service (NTIS)

The review summarizes the available scientific literature from 1971-1976, related to the safety of Vitamin B12 as a food ingredient. Chemical information, biological data, and biochemical aspects of vitamin B12 are given in a 6 page summary containing 13 ...

M. J. Wade

1977-01-01

203

Genetic disorders of vitamin B12 metabolism: eight complementation groups - eight genes  

PubMed Central

Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisation, the genes for eight complementation groups have been identified, leading to the determination of the general structure of vitamin B12 processing and providing methods for carrier testing, prenatal diagnosis and approaches to treatment.

Froese, D. Sean; Gravel, Roy A.

2010-01-01

204

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

PubMed

Approximately one-third of low-income women and children studied in Guatemala are reported to have deficient (<148 pmol/L) or marginal (148-220 pmol/L) plasma vitamin B-12 concentrations. Because vitamin B-12 deficiency can adversely affect infant development and cognitive function, the present study examined predictors of deficient plasma vitamin B-12 concentrations at the age of 12 mo. Analyses were performed on baseline data from a randomized clinical trial in 304 Guatemalan infants, 80% of whom were partially breast-fed, and their mothers. Exclusion criteria for infants included twins, severe stunting or moderate wasting, reported major health problems, severe developmental delay, hemoglobin <95 g/L, maternal age <17 y, and maternal pregnancy >3 mo. Data collected included socio-economic status, infant anthropometry, vitamin B-12 intake from complementary foods, and breast-feeding frequency reported by mothers. A complete blood count and plasma vitamin B-12, folate, ferritin, and C-reactive protein were measured. Deficient or marginal plasma vitamin B-12 concentrations were found in 49% of infants and 68% of mothers. The mean intake of maternal vitamin B-12 was 3.1 microg/d, and infants consumed 2.2 microg/d from complementary foods. In linear regression analysis, infant plasma B-12 concentration was strongly and positively associated with maternal plasma vitamin B-12 and B-12 intake from complementary foods (predominantly powdered cow's milk), and inversely associated with frequency of breast-feeding and larger household size (P < 0.0001). Vitamin B-12 supplementation of lactating women, food fortification, and education to improve infant's vitamin B-12 status are potential interventions that can improve the vitamin B-12 status of mothers and infants in this population. PMID:17449597

Jones, Katharine M; Ramirez-Zea, Manuel; Zuleta, Clara; Allen, Lindsay H

2007-05-01

205

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

206

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.??

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

1997-01-01

207

Prevalent Vitamin B12 Deficiency in Twelve Month-Old Guatemalan Infants Is Predicted by Maternal B12 Deficiency and Infant Diet1,2  

Microsoft Academic Search

Approximately one-third of low-income women and children studied in Guatemala are reported to have deficient (,148 pmol\\/L) or marginal (148-220 pmol\\/L) plasma vitamin B-12 concentrations. Because vitamin B-12 deficiency can adversely affect infant development and cognitive function, the present study examined predictors of deficient plasma vitamin B-12 concentrations at the age of 12 mo. Analyses were performed on baseline data

Katharine M. Jones; Manuel Ramirez-Zea; Clara Zuleta; Lindsay H. Allen

208

Efficacy and safety of fortification and supplementation with vitamin B12: biochemical and physiological effects.  

PubMed

Long known as an uncommon but serious medical disorder requiring medical management, vitamin B12 deficiency is now seen to be common worldwide, but it is in a quite different form than traditionally envisioned. Most of the newly recognized deficiency is subclinical in nature, its health impact and natural history are uncertain, and its prevalence has been greatly inflated by also including persons with "low-normal" vitamin B12 levels, few of whom are deficient. The spread of folic acid fortification has also introduced concerns about folate's potentially adverse neurologic consequences in persons with undetected vitamin B12 deficiency. Fortification with vitamin B12 may prove more complicated than fortification with folic acid, however, because the bioavailability of vitamin B12 is limited. Bioavailability for those who need the vitamin B12 the most is especially poor, because they often have malabsorption affecting either classical intrinsic factor-mediated absorption or food-vitamin B12 absorption. Moreover, new evidence shows that many elderly persons respond poorly to daily oral doses under 500 microg (1 microg = 0.74 nmol), even if they do not have classical malabsorption, which suggests that proposed fortification with 1 to 10 microg may be ineffective. Those least in need of vitamin B12 usually have normal absorption and are thus at greatest risk for whatever unknown adverse effects of high-dose fortification might emerge, such as the effects of excess accumulation of cyanocobalamin. Studies are needed to define the still unproven health benefits of vitamin B12 fortification, the optimal levels of fortification, the stability of such fortification, interactions with other nutrients, and any possible adverse effects on healthy persons. The answers will permit formulation of appropriately informed decisions about mandatory fortification or (because fortification may prove a poor choice) about targeted supplementation in subpopulations with special needs for additional vitamin B12, such as vegetarians, nursing mothers, and the elderly. PMID:18709891

Carmel, Ralph

2008-06-01

209

Vitamin B12 Deficiency and Multiple Sclerosis; Is there Any Association?  

PubMed Central

Background: Vitamin B12 (Cobalamin) deficiency can result in some clinical and paraclinical characteristics similar to what is seen in multiple sclerosis (MS) patients. This study aimed to evaluate the controversial association between vitamin B12 deficiency and MS. Methods: We measured serum vitamin B12 in 60 patients with MS and 38 healthy controls. Clinical disability was evaluated according to the Extended Disability Status Scale (EDSS). Serum B12 concentration was measured with Radioimmunoassay Dual Isotope method. The cutoff value for low serum vitamin B12 concentrations was 75 pg/mL. Patients were in remission at the time of blood draw. Results: There were 13 (21.6%) MS patients and 10 (26.3%) controls with low serum B12 concentration with no significant difference between the groups; P>0.05. The mean serum vitamin B12 concentration in MS patients (108.9±45.3 pg/mL) was not significantly different compared with controls (98.9±44.4 pg/mL); P=0.284. Likewise, there was no correlation between the concentration of serum vitamin B12 and disease’ age of onset, duration, subtypes, or disability status. Conclusions: In contrast to some previous reports, our findings did not support any association between B12 deficiency and MS.

Najafi, Mohamad Reza; Shaygannajad, Vahid; Mirpourian, Maryam; Gholamrezaei, Ali

2012-01-01

210

Nutritional vitamin B12 deficiency in a breastfed infant following maternal gastric bypass.  

PubMed

Breastfed infants of women who have had gastric or intestinal bypass procedures may develop nutritional deficiencies. We describe a 10-month-old exclusively breastfed white male infant who presented with vomiting, failure to thrive, and megaloblastic anemia. He was found to have vitamin B12 deficiency. His mother had undergone a gastric bypass procedure for morbid obesity 2 years prior to her pregnancy with this child. She had subclinical vitamin B12 deficiency, with an abnormal Schilling test that corrected with the addition of intrinsic factor. Therefore, we believe that the mother's gastric bypass had caused a decrease in available intrinsic factor, resulting in subclinical vitamin B12 deficiency and decreased breast milk B12. Although she was asymptomatic, her breastfed infant developed symptomatic B12 deficiency. This is the first reported case of a maternal gastric bypass resulting in vitamin B12 deficiency in an infant. These mothers should receive vitamin supplements, including vitamin B12, during and after pregnancy, and may require parenterally administered vitamin B12. PMID:8060815

Grange, D K; Finlay, J L

211

Vitamin B12 and ageing: current issues and interaction with folate.  

PubMed

A compromised vitamin B12 status is common in older people despite dietary intakes that typically far exceed current recommendations. The maintenance of an optimal status of vitamin B12 is not only dependent on adequate dietary intake but more critically on effective absorption which diminishes with age. The measurement of vitamin B12 is complicated by the lack of a gold standard assay. There are a number of direct and functional indicators of vitamin B12 status; however, none of these are without limitations and should be used in combination. Vitamin B12 is of public health importance, not only because deficiency leads to megaloblastic anaemia and irreversible nerve damage, but also because emerging evidence links low B12 to an increased risk of a number of age-related diseases, including cardiovascular disease, cognitive dysfunction, dementia and osteoporosis. Furthermore, there are concerns relating to potential adverse effects for older adults with low vitamin B12 status of over-exposure to folic acid in countries where there is mandatory fortification of food with folic acid. The aim of this review is to examine the known and emerging issues related to vitamin B12 in ageing, its assessment and inter-relationship with folate. PMID:23592803

Hughes, Catherine F; Ward, Mary; Hoey, Leane; McNulty, Helene

2013-06-18

212

The absorption of free vitamin B12 and R protein-bound vitamin B12 in the diagnosis of pancreatic exocrine insufficiency in rats.  

PubMed

Vitamin B12 (B12) absorption was studied in rats following biliopancreatic duct ligation. The absorption of free B12, as well as of hog R protein-bound B12, was markedly impaired after both intragastric and intraduodenal administration in these rats. The intraduodenal administration of a mixture of pancreatic extract and sodium bicarbonate (NaHCO3) improved the absorption of both free and R protein-bound B12. However, pancreatic extract without NaHCO3 was ineffective in this respect. Intraduodenal administration of NaHCO3 without pancreatic extract worsened the R protein-bound B12 absorption. This finding would indicate that the degradation of R protein by proteolytic enzymes, in the intestine of rats with pancreatic juice exclusion, is inhibited by NaHCO3. PMID:2824630

Chen, W L; Morishita, R; Eguchi, T; Kawai, T; Uchino, H

1987-08-01

213

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

214

Chronic Psychosis Associated with Vitamin B12 Deficiency  

Microsoft Academic Search

B12 deficiency is widely prevalent and usually presents with haematologic and neuropsychiatric manifestations. Psychiatric symptoms seldom precede anaemia and present as the principal manifestation of B12 deficiency. A report an unusual presentation of long standing psychotic symptoms without anaemia in a 31 year old male, who presented to a tertiary care psychiatric facility. His physical examination revealed hyper pigmentation of

AP Rajkumar; P Jebaraj

2008-01-01

215

Vitamin B12 absorption after allogeneic bone marrow transplantation.  

PubMed

The B12 absorption test (Schilling test) with intrinsic factor was used to examine ileal B12 absorption in 26 patients after allogeneic transplantation. The test was well tolerated and showed a profound fall in B12 absorption, which was maximal at two weeks after transplantation and recovered by eight weeks. The predominant influence on absorption at this stage was probably the conditioning schedule, and the presence of acute graft versus host disease (GVHD) was not associated with a further impairment of absorption. Six patients with chronic GVHD were studied. When compared with nine patients without GVHD there was a significant (p less than 0.005) reduction of B12 absorption. These findings suggest that the B12 absorption test may be a useful non-invasive method of studying bowel function after bone marrow transplantation. PMID:3323253

Milligan, D W; Quick, A; Barnard, D L

1987-12-01

216

Vitamin B12 deficiency in the elderly: current dilemmas1'2  

Microsoft Academic Search

Vitamin B-l2 deficiency is present in up to 15% of the elderly population as documented by elevated methylma- lonic acid with or without elevated total homocysteine concentra- tions in combination with low or low-normal vitamin B- 12 con- centrations. Clinical signs and symptoms of vitamin B-12 deficiency are insensitive in elderly subjects and comorbidity in these subjects makes responses to

Sally P Stabler; John Lindenbaum; Robert H Allen

217

Vitamin B12 deficiency in resettled Bhutanese refugees--United States, 2008-2011.  

PubMed

Since 2008, approximately 30,000 Bhutanese refugees have been resettled in the United States. Routine medical examinations of refugees after arrival in resettlement states indicated hematologic and neurologic disorders caused by vitamin B12 deficiency. These cases were reported by examining physicians and state health departments to CDC, which initiated an investigation. This report summarizes the results of that investigation. Sera from overseas medical examinations, postarrival examinations in three state health departments (Minnesota, Utah, and Texas), and medical records and interviews at a health clinic in St. Paul, Minnesota, were evaluated. Vitamin B12 deficiency, defined as serum vitamin B12 concentration <203 pg/mL, was found in 64% (63 of 99) of overseas specimens, 27% (17 of 64) of postarrival medical screenings, and 32% (19 of 60) of Bhutanese refugees screened for vitamin B12 deficiency at the St. Paul clinic. Although the deficiencies might be multifactorial, the main cause is thought to be the diet consumed by these refugees for nearly two decades in Nepal, which lacked meat, eggs, and dairy products, the major dietary sources of vitamin B12. Additionally, infection with Helicobacter pylori might play a role. Clinicians should be aware of the risk for vitamin B12 deficiency in Bhutanese refugees. All Bhutanese refugees should be given nutrition advice and should receive supplemental vitamin B12 upon arrival in the United States. In addition, refugees with clinical manifestations suggestive of deficiency should be tested for adequate serum vitamin B12 concentrations and, if found to have a B12 deficiency, screened for underlying causes, treated with parenteral vitamin B12 or high-dose oral supplements, and evaluated for response to therapy. PMID:21430638

2011-03-25

218

EFFECT OF VITAMIN B12 ON THE GROWING PIG  

Microsoft Academic Search

In an effort to study a possible source of these unknown factors or un- recognized vitamins, the experiment reported herein was conducted in order (~) to determine whether vitamin BI~ would increase the growth rate, feed efficiency, and enhance the blood cell counts of pigs fed purified rations, (2) to compare a crude concentrate of vitamin B,2, a crude concentrate

R. W. COLBY; M. E. ENSMINGER

219

Reversal of protein-bound vitamin B12 malabsorption with antibiotics in atrophic gastritis.  

PubMed

The role of bacteria in the bioavailability of protein-bound vitamin B12 was examined in eight elderly subjects who had atrophic gastritis and in eight normal controls. On separate days and in random order, vitamin B12 absorption tests were performed using either radiolabeled crystalline or protein-bound vitamin B12. At the same time, bacterial samples were collected from the upper gastrointestinal tract. The tests and gastrointestinal aspirates were performed before and during tetracycline therapy. Crystalline vitamin B12 was absorbed to the same extent in the two study groups. Atrophic gastritis subjects absorbed significantly less protein-bound vitamin B12 than normal controls (mean +/- SEM, 0.7% +/- 0.2% vs. 1.9% +/- 0.5%, respectively). However, protein-bound vitamin B12 absorption in these subjects normalized after antibiotic therapy. These results suggest that the small amounts of vitamin B12 released from the protein binders is readily absorbed (as shown in vitro) and/or metabolized by bacteria. PMID:1889697

Suter, P M; Golner, B B; Goldin, B R; Morrow, F D; Russell, R M

1991-10-01

220

Vitamin B12 absorption capacity in healthy children  

SciTech Connect

B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using /sup 57/CoB12 and /sup 51/CrCl/sub 3/, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%).

Hjelt, K.; Krasilnikoff, P.A.

1986-03-01

221

Assessment of peripapillary retinal nerve fiber layer thickness in children with vitamin B12 deficiency.  

PubMed

PURPOSE: Vitamin B12 deficiency is a worldwide problem. It affects all ages, including children. It is one of the most common nutritional disorders and can cause harmful effects on the nervous system. In this study, we compared the peripapillary retinal nerve fiber layer thickness (RNFLT) in a healthy control group with children with vitamin B12 deficiency. In our study, we aimed to evaluate the effect of vitamin B12 deficiency on the RNFLT in children with the optical coherence tomography (OCT) method. METHODS: Sixty-six children with a diagnosis of vitamin B12 deficiency (patient group) and 66 age- and sex-matched healthy children (control group) were enrolled in this prospectively designed study. Blood counts, vitamin B12 levels, folate levels, and full biochemical parameters were obtained for all the subjects in each group. Peripapillary RNFLT measurements were performed with Cirrus HD spectral domain OCT. RESULTS: The thickness of the superior retinal nerve fiber layer (RNFL) in the vitamin B12 deficiency group was significantly lower than that of the control group (p?=?0.037). Although the average thickness of the RNFL was lower in the patient group, there was no statistically significant differences (p?=?0.216). In the vitamin B12 deficiency group, the average RNFL thickness and the superior RNFL thickness were significantly correlated with vitamin B12 levels (r 1?=?0.353, p 1?vitamin B12, elsewhere it is important for the development of the central nervous system, is associated with a reduction in the thickness of the superior RNFL. PMID:23677174

Ozkasap, Serdar; Türkyilmaz, Kemal; Dereci, Selim; Oner, Veysi; Calapo?lu, Tu?ba; Cüre, Medine Cumhur; Durmu?, Mustafa

2013-05-16

222

Nutritional vitamin B12 deficiency in infancy: three case reports and a review of the literature.  

PubMed

Three cases of vitamin B12 deficiency that occurred during infancy are presented. These cases appeared to be the result of pre-existing maternal deficiency. All three infants demonstrated evidence of neurodevelopmental delay at presentation, and one had sustained loss of milestones and developed involuntary motor movements. Prior to the initiation of therapy, all three infants were anemic: one was thrombocytopenic and one pancytopenic. In all three cases the hematologic and neurologic abnormalities were corrected with vitamin B12 therapy. The literature is reviewed and discussed with respect to the mechanism of the infants' vitamin B12 deficiency and neurodevelopmental manifestations. PMID:2702070

Doyle, J J; Langevin, A M; Zipursky, A

1989-01-01

223

Normalization of vitamin B12 absorption after ileal resection in children.  

PubMed

Impaired Vitamin B12 absorption after significant ileal resection has been reported to be permanent, although partial recovery after ileal bypass can occur. Three children are presented in whom Vitamin B12 malabsorption returned to normal 6-8 years after ileal resection. This was due probably to adaptation of the remaining small bowel, although spontaneous resolution of bacterial overgrowth is a possible explanation. An abnormal Schilling test after ileal resection does not automatically imply the need for life-long Vitamin B12 injections. PMID:1562369

Ooi, B C; Barnes, G L; Tauro, G P

1992-04-01

224

Vitamin B12 absorption in some selected pathological states of the gastrointestinal tract.  

PubMed

The absorption of vitamin B12 in selected pathological states of the gastrointestinal tract was studied. Schilling test was performed with 37 kBq (1 microCi) of 57Co-labelled vitamin B12 as an analysis of urinary radioactivity. No increase in cobalamin absorption was present after exogenous IF had been administrated to patients after resection of the upper part the stomach and total gastrectomy. This suggests that there is another factor likely to affect vitamin B12 absorption. PMID:2239025

Boldys, H; Skrzypek, B; Markiewicz, A; Kalacinski, J; Hartleb, M

1990-01-01

225

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 ...

226

Low serum vitamin B12 levels in chronic high-flux haemodialysis patients.  

PubMed

The occurrence of vitamin B12 (B12) deficiency in chronic haemodialysis patients and the need for its supplementation in these patients are still matters of debate. We measured serial predialysis serum B12 levels, at 3- to 6-month intervals, in 67 unselected patients on our high-flux haemodialysis programme. Over a 12-month period, there was a significant fall in serum B12 from 497 +/- 200 (SD) to 391 +/- 131 ng/l (p < 0.001). 22 patients developed subnormal serum B12 levels and were commenced on hydroxocobalamin supplements. We were unable to demonstrate B12 clearance during dialysis using blood side studies. Measurement of B12 in the dialysate showed that 0-4.5 microg B12 was cleared per dialysis. Using these B12 measurements, in vivo B12 clearance was estimated at 9.1 ml/min. Dietary studies on 24 unselected patients showed borderline or low B12 intake in 4 patients. Absorption studies by whole-body counting on 6 patients using 57Co and 58Co showed normal B12 absorption. The same radioisotope studies demonstrated no B12 adsorption to the dialyser membrane. This study demonstrates that low serum B12 levels occur in high-flux haemodialysis patients and that losses during dialysis and dietary deficiency may be contributing factors. PMID:9069445

Chandna, S M; Tattersall, J E; Nevett, G; Tew, C J; O'Sullivan, J; Greenwood, R N; Farrington, K

1997-01-01

227

West syndrome in an infant with vitamin B12 deficiency in the absence of macrocytic anaemia.  

PubMed

Vitamin B(12) deficiency in infants often produces haematological and neurological deficits, including macrocytic anaemia, neurodevelopmental delay or regression, irritability, weakness, hypotonia, ataxia, apathy, tremor, and seizures. The diagnosis of vitamin B(12) deficiency can be difficult when the typical macrocytic anaemia is absent. We report the case of a 10-month-old female diagnosed with West syndrome associated with vitamin B(12) deficiency but without macrocytic anaemia caused by nutritional inadequacy in the mother. The patient's motor skills and cognitive development were normal until she was 9 months old, when she began to exhibit a series of sudden flexions of the head, trunk, arms, and legs. She was exclusively breast-fed and had received no vitamin supplementation. Results of electroencephalography (EEG) indicated modified hypsarrhythmia and the patient was diagnosed as having West syndrome. Synthetic adrenocorticotropic hormone was administered and although her spasms had resolved, the patient remained apathic and could not sit without assistance. EEG results indicated generalized slow activity. After she was diagnosed as having vitamin B(12) deficiency, parenteral treatment with vitamin B(12) was initiated. Her symptoms resolved and EEG was completely normal. When she was 20 months old she exhibited an age-appropriate developmental and neurological profile. To our knowledge, this is the first report of West syndrome as a presenting symptom of vitamin B(12) deficiency. PMID:17880648

Erol, Ilknur; Alehan, Füsun; Gümüs, Ayten

2007-10-01

228

Vegetarianism, vitamin B12 status, and insulin resistance in a group of predominantly overweight\\/obese South Asian women  

Microsoft Academic Search

ObjectivesAsian Indians are an at-risk group for vitamin B12 deficiency (because of vegetarianism) and insulin resistance (IR). Vegetarianism and consequent vitamin B12 deficiency may be associated with IR. This study aimed to describe the vitamin B12 status of predominantly overweight\\/obese women of South Asian origin living in Auckland and to correlate serum vitamin B12 and vegetarian status with IR as

Cheryl S. Gammon; Pamela R. von Hurst; Jane Coad; Rozanne Kruger; Welma Stonehouse

229

Oral vitamin B12 for patients suspected of subtle cobalamin deficiency: a multicentre pragmatic randomised controlled trial  

Microsoft Academic Search

BACKGROUND: Evidence regarding the effectiveness of oral vitamin B12 in patients with serum vitamin B12 levels between 125-200 pM\\/l is lacking. We compared the effectiveness of one-month oral vitamin B12 supplementation in patients with a subtle vitamin B12 deficiency to that of a placebo. METHODS: This multicentre (13 general practices, two nursing homes, and one primary care center in western

Bernard Favrat; Paul Vaucher; Lilli Herzig; Bernard Burnand; Giuseppa Ali; Olivier Boulat; Thomas Bischoff; François Verdon

2011-01-01

230

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 ...

231

Effect of vitamin B12 deficiency on neurodevelopment in infants: current knowledge and possible mechanisms  

Technology Transfer Automated Retrieval System (TEKTRAN)

Severe vitamin B12 deficiency produces a cluster of neurological symptoms in infants, including irritability, failure to thrive, apathy, anorexia, and developmental regression, which respond remarkably rapidly to supplementation. The underlying mechanisms may involve delayed myelination or demyelina...

232

Maternal Milk and Serum Vitamin B12, Folic Acid, and Protein Levels in Indian Subjects  

PubMed Central

Serum vitamin B12 and folic acid activity levels were studied in 47 mothers. The mean serum vitamin B12 value in non-vegetarian mothers was 228 ??g./ml. ± 38·9 SE, as compared to mean values 97 ??g./ml. ± 20·7 SE in lacto-vegetarians. There was no significant difference in folic acid levels, haemoglobin, and total proteins among the different dietetic groups. Analysis of milk revealed mean vitamin B12 values of 103 ??g./ml. in non-vegetarians as compared to 91 ??g./ml. in lacto-vegetarians; the difference was not statistically significant. Mean total protein and folic acid levels for milk were similar in different dietetic groups. The figures obtained for vitamin B12 content of human milk in these mothers are considerably lower than those reported in similar studies from Western countries.

Jathar, V. S.; Kamath, S. A.; Parikh, M. N.; Rege, D. V.; Satoskar, R. S.

1970-01-01

233

Role of Vitamin B12 in the Methionine-Synthesizing System.  

National Technical Information Service (NTIS)

Experiments were performed on animals (Wistar white rats) kept on methionine- and B12 vitamin deficient diets. It showed that maximal growth effect occurred with a simultaneous addition of these substances into the diet. (Similar results were obtained in ...

L. Y. Areshkina V. N. Bukin N. N. Erofeeva L. S. Kutseva E. P. Skorobogatova

1969-01-01

234

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

2009-03-17

235

Microbiological assay for vitamin B12 performed in 96-well microtitre plates  

Microsoft Academic Search

A simplified microbiological assay for vitamin B12 estimation, completed on microtitre plates using a colistin sulphate resistant strain of Lactobacillus leichmannii (NCIB 12519), and cryopreserved cultures is described. The new assay correlated well with a more conventional \\

B P Kelleher; S D Broin

1991-01-01

236

Vitamin B12 Supplement Exerts a Beneficial Effect on the Seminiferous Epithelium of Cimetidine-Treated Rats  

Microsoft Academic Search

Treatment of gastric ulcer with cimetidine reduces acid secretion and interferes in the vitamin B12 absorption. Regarding the harmful effect of cimetidine on the seminiferous tubules, the aim of the present study was to verify if prolonged treatment with cimetidine causes vitamin B12 deficiency and whether the testicular damages are attenuated by vitamin B12 supplementation. Adult male rats received, for

Flávia L. Beltrame; Breno H. Caneguim; Sandra M. Miraglia; Paulo S. Cerri; Estela Sasso-Cerri

2011-01-01

237

Maternal and neonatal vitamin B12 deficiency detected through expanded newborn screening--United States, 2003-2007.  

PubMed

The incidence of neonatal vitamin B12 (cobalamin) deficiency because of maternal deficiency was determined by surveying state newborn screening programs. Thirty-two infants with nutritional vitamin B12 deficiency were identified (0.88/100,000 newborns). Pregnant women should be assessed for their risk of inadequate intake/malabsorption of vitamin B12. PMID:20400092

Hinton, Cynthia F; Ojodu, Jelili A; Fernhoff, Paul M; Rasmussen, Sonja A; Scanlon, Kelley S; Hannon, W Harry

2010-04-18

238

Vitamin B12 status in patients of Turkish and Dutch descent with depression: a comparative cross-sectional study  

Microsoft Academic Search

BACKGROUND: Studies have shown a clear relationship between depressive disorders and vitamin B12 deficiency. Gastroenteritis and Helicobacter pylori infections can cause vitamin B12 deficiency. Helicobacter pylori infections are not uncommon among people of Turkish descent in The Netherlands. AIM: To examine the frequency of vitamin B12 deficiency in depressive patients of Turkish descent and compare it to the frequency of

Yener Güzelcan; Peter van Loon

2009-01-01

239

Traveling the vitamin B12 pathway: oral delivery of protein and peptide drugs.  

PubMed

Oral routes of administration for therapeutic peptides and proteins face two major barriers: proteolytic degradation in the stomach and an inadequate absorption mechanism for polypeptides within the intestinal lumen. As a result, peptide-based therapeutics are administered by injection, a painful process associated with lower patient compliance. The development of a means of overcoming these two major obstacles and enabling the successful delivery of peptide therapeutics by the oral route of administration has therefore been the target of extensive scientific endeavor. This Minireview focuses on oral peptide/protein delivery by the dietary uptake pathway for vitamin B(12). Recent progress in this field includes the delivery of erythropoietin, granulocyte-colony-stimulating factor, luteinizing-hormone-releasing hormone, and insulin. PMID:19072807

Petrus, Amanda K; Fairchild, Timothy J; Doyle, Robert P

2009-01-01

240

Quantitation of vitamin B 12 by first-derivative absorption spectroscopy  

NASA Astrophysics Data System (ADS)

Quantitation of vitamin B 12 by first-derivative absorption spectroscopy is described. Peak-to-peak (355 nm to 370 nm) amplitudes were measured from the first derivative spectra. The method permits rapid determination of vitamin B 12, and increases the detection limit while decreasing interference by impurities. The effects of the majority of other absorbing macromolecules which may also be present in biological samples are eliminated or very considerably minimized by this method.

Kar?ilayan, Huriye

1996-08-01

241

Retardation of myelination due to dietary vitamin B 12 deficiency: cranial MRI findings  

Microsoft Academic Search

Vitamin B12 deficiency is known to be associated with signs of demyelination, usually in the spinal cord. Lack of vitamin B12 in the maternal diet during pregnancy has been shown to cause severe retardation of myelination in the nervous system. We\\u000a report the case of a 14 1\\/2-month-old child of strictly vegetarian parents who presented with severe psychomotor retardation.\\u000a This

Karl-Olof Lövblad; Gianpaolo Ramelli; Luca Remonda; Arto C. Nirkko; Christoph Ozdoba; Gerhard Schroth

1997-01-01

242

Urinary methylmalonic acid as an indicator of the vitamin B12 status of grazing sheep  

Microsoft Academic Search

Lambs grazing cobalt-deficient pastures and injected with hydroxocobalamine gained significantly more weight and excreted significantly less methylmalonic acid in the urine than untreated controls. Lambs with liver vitamin B12 levels in the range 0.1–0.2?g\\/g excreted less than 25 ?g of methylmalonic acid per ml of urine, whereas lambs with liver vitamin B12 concentrations of less than 0.1 ?g\\/g excreted greater

K. R. Millar; P. P. Lorentz

1979-01-01

243

Effect of Cobaltic Oxide Pellets on the Vitamin B12 Content of Ewes' Milk  

Microsoft Academic Search

EVIDENCE that the provision of cobalt-containing supplements to ruminants will increase the vitamin B12 content of their milk is conflicting. Harper et al.1 and Moinuddin et al.2 found that cobaltized mineral mixtures given to ewes fed on dry rations significantly increased vitamin B12 levels in the milk. Other workers3, however, have reported that supplementary feeding with cobalt-containing trace element mixtures

L. I. Hart; E. D. Andrews

1959-01-01

244

Brief report: childhood disintegrative disorder as a likely manifestation of vitamin B12 deficiency.  

PubMed

Childhood disintegrative disorder is a rare disorder, characterized by regression of acquired skills after a period of normal development. The case of childhood disintegrative disorder presented here was found to have vitamin B12 deficiency and hyperhomocysteinemia on extensive evaluation to find a probable cause for regression. This case illustrates the need for a thorough evaluation of all cases of childhood disintegrative disorder so that treatable causes of regression, like vitamin B12 deficiency, are not missed. PMID:23334842

Malhotra, Savita; Subodh, B N; Parakh, Preeti; Lahariya, Sanjay

2013-09-01

245

A water channel in the core of the vitamin B 12 RNA aptamer  

Microsoft Academic Search

Background: The 3.0 Å crystal structure of the vitamin B12 RNA aptamer revealed an unusual tertiary structure that is rich in novel RNA structural motifs. Important details of the interactions that stabilize noncanonical base pairing and the role of solvent in the structure were not apparent owing to the limited resolution.Results: The structure of the vitamin B12 RNA aptamer in

Django Sussman; Charles Wilson

2000-01-01

246

How Nature Builds the Pigments of Life: The Conquest of Vitamin B12  

Microsoft Academic Search

In part because humans cannot synthesize vitamin B12 and must obtain it from organisms that produce it and because B12 deficiency leads to pernicious anemia, it has been important to understand how microorganisms build this quite complex substance. As shown here, an interdisciplinary attack was needed, which combined the strengths of genetics, molecular biology, enzymology, chemistry, and spectroscopy. This allowed

Alan R. Battersby

1994-01-01

247

Folate, vitamin B12 and vitamin B6 and one carbon metabolism.  

PubMed

The vitamins folic acid, B12 and B6 and B2 are the source of coenzymes which participate in one carbon metabolism. In this metabolism, a carbon unit from serine or glycine is transferred to tetrahydrofolate (THF) to form methylene-THF. This is either used as such for the synthesis of thymidine, which is incorporated into DNA, oxidized to formyl-THF which is used for the synthesis of purines, which are building blocks of RNA and DNA, or it is reduced to methyl-THF which used to methylate homocysteine to form methionine, a reaction which is catalyzed by a B12-containing methyltransferase. Much of the methionine which is formed is converted to S-adenosylmethionine (SAM), a universal donor of methyl groups, including DNA, RNA, hormones, neurotransmitters, membrane lipids, proteins and others. Because of these functions, interest in recent years has been growing particularly in the area of aging and the possibility that certain diseases that afflict the aging population, loss of cognitive function, Alzheimer's disease, cardiovascular disease, cancer and others, may be in part explained by inadequate intake or inadequate status of these vitamins. Homocysteine, a product of methionine metabolism as well as a precursor of methionine synthesis, was shown recently to be a risk factor for cardiovascular disease, stroke and thrombosis when its concentration in plasma is slightly elevated. There are now data which show association between elevated plasma homocysteine levels and loss of neurocognitive function and Alzheimer's disease. These associations could be due to a neurotoxic effect of homocysteine or to decreased availability of SAM which results in hypomethylation in the brain tissue. Hypomethylation is also thought to exacerbate depressive tendency in people, and for (colorectal) cancer DNA hypomethylation is thought to be the link between the observed relationship between inadequate folate status and cancer. There are many factors that contribute to the fact that the status of these vitamins in the elderly is inadequate. These factors are in part physiological such as the achlorhydria which affects vitamin B12 absorption and in part socioeconomic and habitual. We need more studies to confirm that these vitamins have important functions in the etiology of these diseases. We also need to establish if these diseases can be prevented or diminished by proper nutrition starting at a younger age. PMID:11813080

Selhub, J

2002-01-01

248

Association between vitamin b12 levels and melancholic depressive symptoms: a Finnish population-based study  

PubMed Central

Background An association between vitamin B12 levels and depressive symptoms (DS) has been reported in several epidemiological studies. The purpose of this study was to evaluate vitamin B12 levels in population-based samples with melancholic or non-melancholic DS as the relationship between vitamin B12 levels and different subtypes of DS has not been evaluated in previous studies. Methods Subjects without previously known type 2 diabetes, aged 45–74 years were randomly selected from the National Population Register as a part of the Finnish diabetes prevention programme (FIN-D2D). The study population (N?=?2806, participation rate 62%) consisted of 1328 men and 1478 women. The health examinations were carried out between October and December 2007 according to the WHO MONICA protocol. The assessment of DS was based on the Beck Depression Inventory (BDI, cut-off ?10 points). A DSM-IV- criteria based summary score of melancholic items in the BDI was used in dividing the participants with DS (N?=?429) into melancholic (N?=?138) and non-melancholic DS (N?=?291) subgroups. In the statistical analysis we used chi-squared test, t-test, permutation test, analysis of covariance, multivariate logistic regression analysis and multinomial regression model. Results The mean vitamin B12 level was 331±176 pmol/L in those without DS while the subjects with non-melancholic DS had a mean vitamin B12 level of 324 ± 135 pmol/L, and those with melancholic DS had the lowest mean vitamin B12 level of 292±112 pmol/L (p?vitamin B12 levels between the non-melancholic and the melancholic group was 33 pmol/L (95%CI 8 to 57, p?=?0.008). Melancholic DS and vitamin B12 levels showed an independent linearly inverse association. The relative risk ratio (RRR) for melancholic DS was 2.75 (95%CI 1.66 to 4.56) in the lowest vitamin B12 level tertile versus the highest (p for linearity <0.001) when those without DS formed the reference group. The RRR in the non-melancholic subgroup was nonsignificant. Conclusions The vitamin B12 level was associated with melancholic DS but not with non-melancholic DS.

2013-01-01

249

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically labeled (14)C-cobalamin.  

PubMed

There is a need for an improved test of human ability to assimilate dietary vitamin B(12). Assaying and understanding absorption and uptake of B(12) is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry is uniquely suited for assessing absorption and kinetics of carbon-14 ((14)C)-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of (14)C in microliter volumes of biological samples with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B(12) in the range of normal dietary intake. The B(12) used was quantitatively labeled with (14)C at one particular atom of the dimethylbenzimidazole (DMB) moiety by exploiting idiosyncrasies of Salmonella metabolism. To grow aerobically on ethanolamine, Salmonella enterica must be provided with either preformed B(12) or two of its precursors, cobinamide and DMB. When provided with (14)C-DMB specifically labeled in the C2 position, cells produced (14)C-B(12) of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) (1 Ci = 37 GBq) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 microg, 2.2 kBq/59 nCi) of purified (14)C-B(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(12) assimilation. PMID:16585531

Carkeet, Colleen; Dueker, Stephen R; Lango, Jozsef; Buchholz, Bruce A; Miller, Joshua W; Green, Ralph; Hammock, Bruce D; Roth, John R; Anderson, Peter J

2006-04-03

250

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically labeled 14C-cobalamin  

PubMed Central

There is a need for an improved test of human ability to assimilate dietary vitamin B12. Assaying and understanding absorption and uptake of B12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry is uniquely suited for assessing absorption and kinetics of carbon-14 (14C)-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of 14C in microliter volumes of biological samples with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B12 in the range of normal dietary intake. The B12 used was quantitatively labeled with 14C at one particular atom of the dimethylbenzimidazole (DMB) moiety by exploiting idiosyncrasies of Salmonella metabolism. To grow aerobically on ethanolamine, Salmonella enterica must be provided with either preformed B12 or two of its precursors, cobinamide and DMB. When provided with 14C-DMB specifically labeled in the C2 position, cells produced 14C-B12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) (1 Ci = 37 GBq) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 ?g, 2.2 kBq/59 nCi) of purified 14C-B12 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 B12 assimilation.

Carkeet, Colleen; Dueker, Stephen R.; Lango, Jozsef; Buchholz, Bruce A.; Miller, Joshua W.; Green, Ralph; Hammock, Bruce D.; Roth, John R.; Anderson, Peter J.

2006-01-01

251

Occurrence of Vitamin B12 in the Sargasso Sea  

Microsoft Academic Search

The concentration of vitamin Blz occurring in Sargasso Sea waters over the period of one year is given. A seasonal cycle in the cuphotic zone corresponding to the cycle of primary production was evidenced. It is postulated that while BJ2 may not control production rates per se, it probably exerts controlling influences on the species composition of the phyto-

DAVID W. MENZEL; JANE P. SPAETH

1962-01-01

252

Effects of moderate alcohol consumption on folate and vitamin B12 status in postmenopausal women  

Microsoft Academic Search

Background: Although alcohol intake has been positively associated with breast cancer risk in epidemiologic studies, a causal relationship has not been established, and the mechanisms mediating this association are speculative. Alcohol may act through altered status of folate and vitamin B12, two vitamins required for DNA methylation and nucleotide synthesis, and thus cell integrity. Although the effects of heavy alcohol

E M Laufer; T J Hartman; D J Baer; E W Gunter; J F Dorgan; W S Campbell; B A Clevidence; E D Brown; D Albanes; J T Judd; P R Taylor

2004-01-01

253

PYRIDOXAL, FOLATE AND VITAMIN B12 CONCENTRATIONS IN WESTERN AUSTRALIAN ABORIGINES  

Microsoft Academic Search

Serum vitamin B6 (pyridoxal), folate and vitamin B12 concentrations were measured in blood samples from 293 Western Australian Aborigines living in the Cundeelee and Meekatharra areas. Twenty-one per cent of males and 25% of females from the Cundeelee area had a low serum pyridoxal compared with 39% and 31% respectively from the Meekatharra area. Twelve per cent of Aborigines below

RE Davis; BK Smith; DH Curnow

1975-01-01

254

Laboratory Diagnosis of Vitamin B12 and Folate Deficiency A Guide for the Primary Care Physician  

Microsoft Academic Search

t one time, the diagnosis of a deficiency of vitamin B12 or folate was considered to be relatively straightforward. As knowledge has accumulated, the limitations of such tests as serum vitamin level measurements and the Schilling test have become apparent. With the development of newer tests, atypical and subclinical deficiency states have been recognized. In this review, available tests used

Christopher F. Snow

255

Elevated serum homocysteine as a predictor for vitamin B12 or folate deficiency.  

PubMed

Tissue deficiency of vitamin B12 and folate results in an increase in serum homocysteine (sHcy). We have measured sHcy in patients with reduced serum vitamin B12 and/or red cell folate (RCF) to determine its usefulness as a discriminant for the diagnostic interpretation of reduced vitamin levels. Of 3846 patients who had serum vitamin B12 and RCF assayed, 335 (9%) had reduced vitamin levels. Multivariate analysis showed a significant association between sHcy and serum creatinine (p = 0.0001), positive intrinsic factor (IF) antibody or neutrophil hypersegmentation (NHS) (p = 0.001), increased MCV (p = 0.014) and low RCF (p = 0.025) but no relationship with the level of serum vitamin B12 or haemoglobin. After censoring the patients with renal impairment (n = 54), the distribution of the remaining 72 patients with elevated sHcy was 37/151 (25%) with low serum vitamin B12 with or without low RCF and 35/130 (27%) with low RCF alone. sHcy correctly identified response to vitamin therapy in 33/35 (94%) patients who had adequate parameters to assess response. The positive predictive values of IF antibody/NHS, macrocytosis and/or low RCF for elevated sHcy were 100% and 34% respectively. Twenty-four percent of patients with a low serum vitamin B12 and elevated sHcy had no abnormal haematologic parameters as determined by the routine laboratory staff. These data suggest that the usefulness of measuring sHcy in a routine diagnostic setting is limited and a careful review of the peripheral blood for macrocytosis and NHS plus determination of RCF may be a more cost-effective process than sHcy assay in most instances to determine the presence of tissue deficiency. PMID:8005233

Curtis, D; Sparrow, R; Brennan, L; Van der Weyden, M B

1994-04-01

256

Broth from canned clams is suitable for use as an excellent source of free vitamin B12.  

PubMed

Vitamin B(12) was assayed and characterized in the broth of canned clams (boiled plain). The broth contained considerable amounts of vitamin B(12) (2.7-14.1 ?g/100 g, 1.3-6.7 ?g/can). HPLC and LC/ESI-MS/MS chromatograms demonstrated that the clam broth contained true vitamin B(12). Gel filtration experiments indicated that most (72%) of the vitamin B(12) found in the broth was recovered in free vitamin B(12) fractions. These results indicate that the clam broth would be suitable for use an excellent source of free vitamin B(12) for elderly persons with food-bound vitamin B(12) malabsorption. PMID:22026331

Ueta, Kazumi; Takenaka, Shigeo; Yabuta, Yukinori; Watanabe, Fumio

2011-10-25

257

Effect of oral vitamin B12 with or without folic acid on cognitive function in older people with mild vitamin B12 deficiency: a randomized, placebo-controlled trial1-3  

Microsoft Academic Search

Background:Vitamin B-12 deficiency is associated with cognitive impairment in older people. However, evidence from randomized trials of the effects of vitamin B-12 supplementation on cognitive function is limited and inconclusive. Objective: The objective was to investigate whether daily supple- mentation with high doses of oral vitamin B-12 alone or in combi- nationwithfolicacidhasanybeneficialeffectsoncognitivefunction in persons aged 70 y with mild vitamin

Simone J Eussen; Lisette C de Groot; Liesbeth W Joosten; Rubia J Bloo; Robert Clarke; Per M Ueland; Jörn Schneede; Henk J Blom; Willibrord H Hoefnagels; Wija A van Staveren

258

Effects of folate and vitamin B12 deficiencies during pregnancy on fetal, infant, and child development.  

PubMed

The importance of folate in reproduction can be appreciated by considering that the existence of the vitamin was first suspected from efforts to explain a potentially fatal megaloblastic anemia in young pregnant women in India. Today, low maternal folate status during pregnancy and lactation remains a significant cause of maternal morbidity in some communities. The folate status of the neonate tends to be protected at the expense of maternal stores; nevertheless, there is mounting evidence that inadequate maternal folate status during pregnancy may lead to low infant birthweight, thereby conferring risk of developmental and long-term adverse health outcomes. Moreover, folate-related anemia during childhood and adolescence might predispose children to further infections and disease. The role of folic acid in prevention of neural tube defects (NTD) is now established, and several studies suggest that this protection may extend to some other birth defects. In terms of maternal health, clinical vitamin B12 deficiency may be a cause of infertility or recurrent spontaneous abortion. Starting pregnancy with an inadequate vitamin B12 status may increase risk of birth defects such as NTD, and may contribute to preterm delivery, although this needs further evaluation. Furthermore, inadequate vitamin B12 status in the mother may lead to frank deficiency in the infant if sufficient fetal stores of vitamin B12 are not laid down during pregnancy or are not available in breastmilk. However, the implications of starting pregnancy and lactation with low vitamin B12 status have not been sufficiently researched. PMID:18709885

Molloy, Anne M; Kirke, Peadar N; Brody, Lawrence C; Scott, John M; Mills, James L

2008-06-01

259

A new 13C breath test to detect vitamin B12 deficiency: a prevalent and poorly diagnosed health problem  

Microsoft Academic Search

Vitamin B12 deficiency is emerging as a growing public health problem. The most commonly used diagnostic tests are limited in accuracy, sensitivity, and are non-specific for B12 deficiency. The aim of this study was to develop a simple B12 breath test (BBT) to more accurately evaluate vitamin B12 status as an alternative to the most common diagnostic test, serum B12

David A. Wagner; Richard Schatz; Richard Coston; Cheryl Curington; Daniel Bolt; Phillip P. Toskes

2011-01-01

260

Studies on vitamin B12 status in the elderly--prophylactic and therapeutic consequences.  

PubMed

Because of the large liver stores (about 5 mg), low turnover rate (0.143%) and small daily requirement (3 micrograms), vitamin B12 deficiency does not occur under normal circumstances. This is not the case in individuals with chronic inflammatory or trophic changes at vitamin B12 absorption sites. Without supplementation, vitamin B12 deficiency can be expected within 5 years of gastrectomy. Characteristic features of type A gastritis are hyposecretion and mucosal atrophy in the fundus and body of the stomach, with absent intrinsic factor. In the small intestine, active and/or passive absorption is impaired by extensive ileal resection, exocrine pancreatic insufficiency and chronic inflammatory disorders such as Crohn's disease. Definitive plasma concentrations cannot be quoted for vitamin B12 deficiency. Dietary habits, subjective symptoms, hematological laboratory results, function tests and gastrointestinal endoscopic and histological findings must all be taken into account in the diagnosis. Modern diagnostic parameters, such as methylmalonic acid and homocysteine serum assays, are useful for achieving early diagnosis and hence optimal treatment. With their assured availability, parenteral vitamin B12 preparations remain the treatment of choice. Results from vitamin B12 bioavailability studies in healthy subjects suggest that > 300 micrograms probably suffices as an oral maintenance dose after parenteral loading. Further well-documented cases are needed in order to establish whether these doses are adequate in malabsorption syndromes and gastrointestinal diseases. Various case reports indicate the value of prophylactic and therapeutic oral vitamin B12 administration, especially in disorders of homocysteine metabolism, a substance postulated as a further important risk factor for atherosclerosis. PMID:10389032

Loew, D; Wanitschke, R; Schroedter, A

1999-05-01

261

Imerslund-Gr?sbeck syndrome (selective vitamin B12 malabsorption with proteinuria)  

PubMed Central

Imerslund-Gräsbeck syndrome (IGS) or selective vitamin B12 (cobalamin) malabsorption with proteinuria is a rare autosomal recessive disorder characterized by vitamin B12 deficiency commonly resulting in megaloblastic anemia, which is responsive to parenteral vitamin B12 therapy and appears in childhood. Other manifestations include failure to thrive and grow, infections and neurological damage. Mild proteinuria (with no signs of kidney disease) is present in about half of the patients. Anatomical anomalies in the urinary tract were observed in some Norwegian patients. Vitamin B12 absorption tests show low absorption, not corrected by administration of intrinsic factor. The symptoms appear from 4 months (not immediately after birth as in transcobalamin deficiency) up to several years after birth. The syndrome was first described in Finland and Norway where the prevalence is about 1:200,000. The cause is a defect in the receptor of the vitamin B12-intrinsic factor complex of the ileal enterocyte. In most cases, the molecular basis of the selective malabsorption and proteinuria involves a mutation in one of two genes, cubilin (CUBN) on chromosome 10 or amnionless (AMN) on chromosome 14. Both proteins are components of the intestinal receptor for the vitamin B12-intrinsic factor complex and the receptor mediating the tubular reabsorption of protein from the primary urine. Management includes life-long vitamin B12 injections, and with this regimen, the patients stay healthy for decades. However, the proteinuria persists. In diagnosing this disease, it is important to be aware that cobalamin deficiency affects enterocyte function; therefore, all tests suggesting general and cobalamin malabsorption should be repeated after abolishment of the deficiency.

Grasbeck, Ralph

2006-01-01

262

Mutualistic interactions between vitamin B12 -dependent algae and heterotrophic bacteria exhibit regulation.  

PubMed

Many algae are auxotrophs for vitamin B(12) (cobalamin), which they need as a cofactor for B(12) -dependent methionine synthase (METH). Because only prokaryotes can synthesize the cobalamin, they must be the ultimate source of the vitamin. In the laboratory, a direct interaction between algae and heterotrophic bacteria has been shown, with bacteria supplying cobalamin in exchange for fixed carbon. Here we establish a system to study this interaction at the molecular level. In a culture of a B(12) -dependent green alga Chlamydomonas nivalis, we found a contaminating bacterium, identified by 16S rRNA analysis as Mesorhizobium sp. Using the sequenced strain of M.?loti (MAFF303099), we found that it was able to support the growth of B(12) -dependent Lobomonas rostrata, another green alga, in return for fixed carbon. The two organisms form a stable equilibrium in terms of population numbers, which is maintained over many generations in semi-continuous culture, indicating a degree of regulation. However, addition of either vitamin B(12) or a carbon source for the bacteria perturbs the equilibrium, demonstrating that the symbiosis is mutualistic and facultative. Chlamydomonas reinhardtii does not require B(12) for growth because it encodes a B(12) -independent methionine synthase, METE, the gene for which is suppressed by addition of exogenous B(12) . Co-culturing C.?reinhardtii with M.?loti also results in reduction of METE expression, demonstrating that the bacterium can deliver the vitamin to this B(12) -independent alga. We discuss the implications of this for the widespread distribution of cobalamin auxotrophy in the algal kingdom. PMID:22463064

Kazamia, Elena; Czesnick, Hjördis; Nguyen, Thi Thanh Van; Croft, Martin Tom; Sherwood, Emma; Sasso, Severin; Hodson, Sarah James; Warren, Martin James; Smith, Alison Gail

2012-03-29

263

[Vitamin B 12 deficiency in strict vegetarian diet. Why do some people choose such a diet, and what will they do in case of vitamin B 12 deficiency].  

PubMed

Nine persons in the county of Troms, Norway, were interviewed on their strict vegetarian diet. Improved health was indicated as the main reason for their choice of diet, but religion was a contributing reason for some. Most of the study persons would increase the intake of vitamin B12 if a deficiency state were to occur. One person reported, however, that she would not regard vitamin B12 deficiency as a health problem. The interviews disclosed beliefs regarding human physiology that are very far removed from standard scientific knowledge. The article indicates that communication between patient and the health care system may be difficult in such circumstances. Problems of communication would probably be minimized if the patient had a thorough understanding of human physiology and the health worker a thorough understanding of the reasons for the patient's choice of diet. PMID:2000592

Johnsen, J B; Fønnebø, V

1991-01-10

264

Serum iron, vitamin B12 and folic acid levels in Parkinson's disease.  

PubMed

We aimed to investigate possible associations between systemic iron metabolism deficiency and Parkinson's disease, and also to research any possible correlations between stage of the disease and vitamin B12 and folic acid levels. 33 male and 27 female patients diagnosed with idiopathic Parkinson's disease and 22 male and 20 female age- and sex-matched controls were enrolled in the study. Having the diagnosis of secondary Parkinsonism or Parkinson plus syndromes, and for the females, not being in the menopausal stage were considered as exclusion criteria. Recordings of blood samples of both groups collected after 8 h fasts were assessed in terms of serum iron, ferritin levels and iron-binding capacity, vitamin B12 and folic acid levels. The Hoehn and Yahr scale was used to determine the stage of the disease. No statistically significant difference was found with respect to mean serum iron, median serum ferritin levels and median serum iron-binding capacity between the groups. A statistically significant but inverse correlation was found between symptoms' duration and serum iron and ferritin levels. There was no statistically significant difference between the groups with respect to vitamin B12 and folic acid levels. However, a statistically significant but inverse correlation was determined between the patients' vitamin B12 levels and the Hoehn and Yahr scores. As Parkinson's disease progresses, serum iron, ferritin and vitamin B12 levels may decrease. The lower levels of these parameters may be the cause of the progression or may be the result of it. PMID:22367474

Madenci, Gulizar; Bilen, Sule; Arli, Berna; Saka, Mustafa; Ak, Fikri

2012-02-26

265

[Vitamin B(12) deficiency anaemia in a 7.5 months old girl].  

PubMed

Vitamin B(12) stores at birth are adequate for infants until the end of the first year of life even if it 's concentration in maternal breast milk is low. However, there are some situations in which infants have depleted vitamin B(12) stores and in addition have a low dietary intake of cobalamin. Vitamin B(12) depletion occurs in infants who are exclusively breastfed by mothers who have unrecognized pernicious anemia or are strict vegetarians for many years. In those infants symptoms of bone marrow disfunction and impaired development of the central nervous system appear already in the first months of life. Unrecognized cobalamin deficiency may lead to serious neurologic consequences, and even to the death of the child. The authors present a case of a 7.5 month old girl admitted to the Department of Paediatrics, Haematology, Oncology and Endocrinology. Gda?sk Medical University suspected of acute leukaemia. Based on a detailed diagnostic procedure a final diagnosis of vitamin B(12) deficiency anaemia was established. The child was exclusively breast-fed. Results of investigations into the reason for cobalamin deficiency in the patient s organism. Led to the diagnosis of pernicious anaemia in the mother. Such a suspicion had been made during pregnancy, but no continuation of investigations nor appropriate treatment were implemented. After treatment with vitamin B(12) supplements and modification of the diet the patient improved quickly and remarkably. A few months follow-up was enough to observe remarkable improvement of psychomotor development of this child. PMID:15738604

Jarosz, Malgorzata; Irga, Ninela; Wierzba, Jolanta

266

Vitamin B12 deficiency and the lack of its consequences in type 2 diabetes patients using metformin.  

PubMed

Objectives: To study vitamin B12 concentrations in patients with type 2 diabetes with and without metformin use and to identify risk factors and consequences of low vitamin B12 concentrations. Research design and methods: This study had a cross-sectional design. During eight weeks all patients with type 2 diabetes visiting the diabetic outpatient clinic of the Isala Clinics in Zwolle were approached for participation. Participation included measurement of haemoglobin, mean corpuscular volume and vitamin B12 levels. Data on neuropathy were retrospectively searched for in the patient records. Vitamin B12 deficiency was defined as serum B12 concentrations. PMID:24038568

de Groot-Kamphuis, D M; van Dijk, P R; Groenier, K H; Houweling, S T; Bilo, H J G; Kleefstra, N

2013-09-01

267

Homocysteine, vitamin B12, serum and erythrocyte folate in peritoneal dialysis patients.  

PubMed

Plasma homocysteine (tHcy) is an important risk factor for atherosclerosis in dialysis patients. Few data were reported on the prevalence and severity of hyperhomocysteinemia in peritoneal dialysis (PD) patients. In addition, little attention was paid to the search of factors possibly involved in the pathogenesis of hyperhomocysteinemia in these patients. A cross-sectional study was performed in 107 stable PD patients. None of them was given folate or vitamin B12 supplementation before or during the study. Plasma tHcy, serum vitamin B12, serum and erythrocyte folate were measured by immunoenzymatic methods. Genetic analysis of the methylentetrahydrofolate-reductase thermolabile mutation (tMTHFR) was performed in 61 patients. 97% of patients had tHcy levels higher than normal. tHcy was not different between men and women, patients with or without malnutrition, with or without clinically evident atherosclerotic vasculopathy, with or without anemia. tHcy levels were significantly higher in homozygotes for the tMTHFR mutation than in patients carrying the wild type form. Significant univariate correlation was found between hyperhomocysteinemia and time since the start of dialysis, serum and erythrocyte folate and vitamin B12. The best fitted model equation was log tHcy = 108.53 + 0.1606 (duration of dialysis) -1.1053 (s-F) -0.7980 (age) 0.0215 (vitamin B12). Our results agree with those reported by other authors in hemodialysis patients. Despite the large number of PD patients with normal serum vitamin B12 and folate status, the relation between tHcy and vitamin B12 or folate suggests that the supplementation of these vitamins could be useful irrespective of their serum levels, especially in younger patients or in those treated for a long period of time with peritoneal dialysis. PMID:11334318

De Vecchi, A F; Bamonti-Catena, F; Finazzi, S; Patrosso, C; Taioli, E; Novembrino, C; Colucci, P; Lando, G; De Franceschi, M; Marocchi, A; Maiolo, A T

2001-04-01

268

An investigation of the relationship between vitamin B12 deficiency and HIV infection.  

PubMed

The symptoms of vitamin B12 deficiency and several symptoms common to HIV infection overlap. Additionally, persons with HIV infection have frequently been found to have vitamin B12 deficiency. Therefore, the issue of concern is the prevalence of B12 deficiency in HIV-infected persons. A retrospective study of 63 medical records in a midwestern urban veterans affairs medical center provided the data for this study. Data were collected and analyzed for relationships among B12 levels, certain hematologic components, medications, symptomatology, and immune status. A chi-square goodness-of-fit test demonstrated a significant prevalence of B12 deficiency among persons with HIV disease, and chi-square two-way tables demonstrated significant relationships between B12 deficiency and weight loss and diarrhea. Prevalence of B12 deficiency in persons with HIV infection has been shown to be significant, indicating that B12 deficiency screening in persons with HIV infection may need be done to aid the health care provider in planning the best possible care. Further research is needed to corroborate these findings. PMID:10670004

Balt, C A

269

Characterisation of vitamin B12 immunoaffinity columns and method development for determination of vitamin B12 in a range of foods, juices and pharmaceutical products using immunoaffinity clean-up and high performance liquid chromatography with UV detection  

Microsoft Academic Search

New rapid and simpler procedures, using immunoaffinity columns, have been developed for the determination of vitamin B12 in a range of samples including three different US National Institute of Standard and Technology (NIST) Reference Materials, infant formula, powdered energy drinks and bars, wheat breakfast cereal, carbonated soft drinks, fruit juices and vitamin B12 tablets. The procedures involved extraction of vitamin

E. C. Marley; E. Mackay; G. Young

2009-01-01

270

The nutritional status of iron, folate, and vitamin B-12 of Buddhist vegetarians.  

PubMed

Nutritional status of iron, folate, and vitamin B-12 in vegetarians were assessed and compared with those of non- vegetarians in Korea. The vegetarian subjects were 54 Buddhist nuns who ate no animal source food except for dairy products. The non-vegetarians were divided into two groups: 31 Catholic nuns and 31 female college students. Three-day dietary records were completed, and the blood samples were collected for analyzing a complete blood count, and serum levels of ferritin, folate, and vitamin B-12. There was no difference in hemoglobin among the diet groups. The serum ferritin and hematocrit levels of vegetarians did not differ from that of non- vegetarian students with a high intake of animal source food but low intake of vitamin C, and the levels were lower than that of non-vegetarian Catholic nuns with a modest consumption of animal source food and a high intake of vitamin C. The serum vitamin B-12 levels of all subjects except one vegetarian and the serum folate levels of all subjects except one non-vegetarian student fell within a normal range. In vegetarians, there was a positive correlation between the vitamin C intake and serum ferritin levels as well as between the laver intake and serum vitamin B-12 levels. In order to achieve an optimal iron status, both an adequate amount of iron intake and its bioavailability should be considered. Sufficient intake of vegetables and fruits was reflected in adequate serum folate status. Korean laver can be a good source of vitamin B-12 for vegetarians. PMID:21393109

Lee, Yujin; Krawinkel, Michael

2011-01-01

271

Distributions of dissolved vitamin B 12 and Co in coastal and open-ocean environments  

NASA Astrophysics Data System (ADS)

Distributions of dissolved vitamin B 12 and total dissolved Co were measured to gain an understanding of the cycling of these interdependent micronutrients in six marine settings including; an upwelling location, a semi-enclosed bay, two urban coastal systems, and two open ocean locations. Along the coast of Baja California, Mexico, concentrations of B 12 and dissolved Co varied from 0.2 to 11 pM and 180 to 990 pM, respectively. At a nearby upwelling station, vitamin B 12 and Co concentrations ranged from 0.3 to 7.0 pM and 22 to 145 pM, and concentrations did not correlate with upwelling intensity. Concentrations of B 12 were highest within Todos Santos Bay, a semi-enclosed bay off the coast of Baja California, Mexico, during a dinoflagellate bloom, ranging from 2 to 61 pM, while Co concentrations varied between 61 and 194 pM. In the anthropogenically impacted Long Island Sound, NY, U.S.A., B 12 levels were between 0.1 and 23 pM and Co concentrations varied from 60 to 1900 pM. However, anthropogenic inputs were not evident in B 12 levels in the San Pedro Basin, located outside Los Angeles, Ca, U.S.A., where concentrations of B 12 were 0.2-1.8 pM, approximating observed open ocean B 12 concentrations. In the Southern Ocean and North Atlantic Ocean, B 12 levels were 0.4-4 pM and 0.2-2 pM, respectively. Total Co concentrations in the Southern Ocean and North Atlantic tended to be low; measuring 26-59 pM and 15-80 pM, respectively. These low Co concentrations may limit B 12 synthesis and its availability to B 12-requiring phytoplankton because the total dissolved Co pool is not necessarily entirely bioavailable.

Panzeca, Caterina; Beck, Aaron J.; Tovar-Sanchez, Antonio; Segovia-Zavala, Jose; Taylor, Gordon T.; Gobler, Christopher J.; Sañudo-Wilhelmy, Sergio A.

2009-11-01

272

Long-term neurologic consequences of nutritional vitamin B12 deficiency in infants.  

PubMed

A review of the clinical findings in six infants with nutritional vitamin B12 deficiency seen during the last 10 years was undertaken and an attempt made to obtain long-term neurologic follow-up. There was a consistent clinical pattern in vitamin B12-deficient infants; irritability, anorexia, and failure to thrive were associated with marked developmental regression and poor brain growth. Two of the four patients who qualified for long-term review had a poor intellectual outcome. Although early response to treatment is satisfying, the long-term consequences of nutritional vitamin B12 deficiency in infants emphasize the need for prevention or early recognition of this syndrome. PMID:1432418

Graham, S M; Arvela, O M; Wise, G A

1992-11-01

273

Oral vitamin B12 therapy in the primary care setting: a qualitative and quantitative study of patient perspectives  

Microsoft Academic Search

BACKGROUND: Although oral replacement with high doses of vitamin B12 is both effective and safe for the treatment of B12 deficiency, little is known about patients' views concerning the acceptability and effectiveness of oral B12. We investigated patient perspectives on switching from injection to oral B12 therapy. METHODS: This study involved a quantitative arm using questionnaires and a qualitative arm

Jeff C Kwong; David Carr; Irfan A Dhalla; Denise Tom-Kun; Ross EG Upshur

2005-01-01

274

Determination of vitamin B 12 in multivitamin tablets by multimode high-performance liquid chromatography  

Microsoft Academic Search

Quantitative determination of vitamin B12 in B-complex tablets was performed by using multimode high-performance liquid chromatography. The multivitamin tablets (B1, B6 and B12) were sonicated for 30 min in methanol–water (50:50, v\\/v) and diluted to appropriated volume with the same solvent. The resulting solution was filtered and the filtrate was analysed on a phenylpropanolamine bonded silica column (15 cm×4.6 mm

Surapote Wongyai

2000-01-01

275

Familial selective vitamin B12 malabsorption (Imerslund-Gräsbeck syndrome) in a pool of Turkish patients.  

PubMed

Thirty-six patients with Imerslund-Gräsbeck syndrome are presented. The mean ages at presentation and diagnosis were 4.7 +/- 3.7 years and 7.2 +/- 4.2 years, respectively. The mean hemoglobin level was 5.8 +/- 2.2 g/dL, the mean cell volume was 104.9 +/- 11.6 fL, the white blood cell count was 4479 +/- 2022/mm3, and the serum vitamin B12 level was 96.9 +/- 73 pg/mL. At diagnosis, 5 of the 36 patients, aged 5 to 16 years, had neurologic symptoms. All the patients had severe megaloblastic changes in bone marrow precursor cells. Proteinuria was detected in 78% of them. Patients with proteinuria had a younger age of onset (P < 0.0001) and diagnosis (P < 0.001) compared with those without proteinuria. In all patients, vitamin B12 excretion unbound to intrinsic factor after a flushing dose of vitamin B12 was lower than normal, and there was no appreciable correction in urinary vitamin B12 excretion after binding of intrinsic factor. The impairment of vitamin B12 absorption studies in Schilling tests; however, showed great variation among patients. Serum haptoglobin values were close to zero in all patients, indicating the presence of that intravascular hemolysis in Imerslund-Gräsbeck syndrome. Variations among patients in the age of presentation, degree of impairment of vitamin B12 absorption, and presence or absence of proteinuria suggest a heterogeneity in etiology of Imerslund-Gräsbeck syndrome at the molecular level. PMID:7703038

Altay, C; Cetin, M; Gümrük, F; Irken, G; Yetgin, S; Laleli, Y

276

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

PubMed Central

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.

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

2013-01-01

277

Potential cobalt limitation of vitamin B12 synthesis in the North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

While recent studies have confirmed the ecological importance of vitamin B12, it is unclear whether the production of this vitamin could be limited by dissolved Co, a trace metal required for B12 biosynthesis, but found at only subnanomolar concentrations in the open ocean. Herein, we demonstrate that the spatial distribution of dissolved B12 (range: 0.13-5 pmol L-1) in the North Atlantic Ocean follows the abundance of total dissolved Co (range: 15-81 pmol L-1). Similar patterns were observed for bacterial productivity (range: 20-103 pmol 3H leucine L-1 hr-1) and algal biomass (range: 0.4-3.9 ?g L-1). In contrast, vitamin B1 concentrations (range: 0.7-30 pM) were decoupled from both Co and B12 concentrations. Cobalt amendment experiments carried out in low-dissolved Co waters (˜20 pmol L-1) enhanced B12 production two-fold over unamended controls. This study provides evidence that B12 synthesis could be limited by the availability of Co in some regions of the world ocean.

Panzeca, C.; Beck, A. J.; Leblanc, K.; Taylor, G. T.; Hutchins, D. A.; SañUdo-Wilhelmy, S. A.

2008-06-01

278

Concurrent changes in serum vitamin B12 and methylmalonic acid during cobalt or vitamin B12 supplementation of lambs while suckling and after weaning on properties in the South Island of New Zealand considered to be cobalt-deficient  

Microsoft Academic Search

AIM: To compare serum analyses of vitamin B12 and methylmalonic acid (MMA) as indices of cobalt\\/vitamin B12 deficiency in lambs around weaning.METHODS: Lambs on five properties, considered to be cobalt- deficient, were supplemented with either cobalt bullets, or short- or long-acting vitamin B12 preparations. Blood samples, and in some cases liver biopsies, and liveweights were obtained at monthly intervals. Serum

Tini M Gruner; JR Sedcole; JM Furlong; ND Grace; Stephen D Williams; G Sinclair; JD Hicks; AR Sykes

2004-01-01

279

Circulating folate, vitamin B12, homocysteine, vitamin B12 transport proteins and risk of prostate cancer: a case-control study, systematic review and meta-analysis  

PubMed Central

Background Disturbed folate metabolism is associated with an increased risk of some cancers. Our objective was to determine whether blood levels of folate, vitamin B12 and related metabolites were associated with prostate cancer risk. Methods Matched case-control study nested within the UK population-based ProtecT study of PSA-detected prostate cancer in men aged 50–69 years. Plasma concentrations of folate, B12 (cobalamin), holo-haptocorrin, holo- and total-transcobalamin, and total homocysteine (tHcy) were measured in 1,461 cases and 1,507 controls. ProtecT study estimates for associations of folate, B12, and tHcy with prostate cancer risk were included in a meta-analysis, based on a systematic review. Results In the ProtecT study, increased B12 and holo-haptocorrin concentrations showed positive associations with prostate cancer risk (highest vs lowest quartile of B12 odds ratio (OR)=1.17 (95% CI 0.95–1.43), P-for-trend=0.06; highest vs lowest quartile of holo-haptocorrin OR=1.27 (1.04–1.56), P-for-trend=0.01); folate, holo-transcobalamin and tHcy were not associated with prostate cancer risk. In the meta-analysis, circulating B12 levels were associated with an increased prostate cancer risk (pooled OR=1.10 (1.01–1.19) per 100 pmol/L increase in B12, P=0.002); the pooled OR for the association of folate with prostate cancer was positive (OR=1.11 (0.96–1.28) per 10 nmol/L, P=0.2) and conventionally statistically significant if ProtecT (the only case-control study) was excluded (OR=1.18 (1.00–1.40) per 10 nmol/L, P=0.02). Conclusion Vitamin B12 and (in cohort studies) folate were associated with increased prostate cancer risk. Impact Given current controversies over mandatory fortification, further research is needed to determine whether these are causal associations.

Collin, Simon M.; Metcalfe, Chris; Refsum, Helga; Lewis, Sarah J.; Zuccolo, Luisa; Smith, George Davey; Chen, Lina; Harris, Ross; Davis, Michael; Marsden, Gemma; Johnston, Carole; Lane, J. Athene; Ebbing, Marta; B?naa, Kaare Harald; Nygard, Ottar; Ueland, Per Magne; Grau, Maria V.; Baron, John A.; Donovan, Jenny; Neal, David E.; Hamdy, Freddie C.; Smith, A. David; Martin, Richard M.

2013-01-01

280

Studies on the spin Hamiltonian parameters of vitamin B 12r  

NASA Astrophysics Data System (ADS)

The spin Hamiltonian parameters g factors gi ( i = x, y, z) and the hyperfine structure constants Ai of vitamin B 12r have been theoretically studied from the perturbation formulas of these parameters for a Co 2+(3d 7) ion with low spin ( S = 1/2) in rhombically distorted octahedra. The related crystal-field parameters are determined from the point-charge-dipole model and the local structure around Co 2+ in vitamin B 12r. The theoretical spin Hamiltonian parameters are in good agreement with the experimental data.

Wu, Shao-Yi; Wei, Li-Hua; Zhang, Zhi-Hong; Wang, Xue-Feng

2009-01-01

281

Early treatment causes clinicoradiological reversal of myelopathy due to vitamin B12 deficiency.  

PubMed

Vitamin B12 deficiency has a wide spectrum of clinical presentation with a variety of neurological symptoms and signs. As a result, many patients lack classic features of advanced severe deficiency. Early diagnosis and treatment are crucial in order to prevent the irreversible damage to the nervous system. We describe a 25-year-old man, who presented with predominant sensory symptoms without any signs on clinical evaluation. His serum vitamin B12 levels were low and neuroimaging revealed myelopathy. The patient was treated promptly with cyanocobalamin injections, which lead to a rapid resolution of symptoms and radiological abnormalities. PMID:23715834

Verma, Rajesh; Kori, Prakash; Patil, Tushar B; Praharaj, Heramba Narayan

2013-05-27

282

Vitamin B12, folate, and homocysteine in depression: the Rotterdam Study  

Microsoft Academic Search

OBJECTIVE: The associations of vitamin B(12), folate, and homocysteine\\u000a with depression were examined in a population-based study. METHOD: The\\u000a authors screened 3,884 elderly people for depressive symptoms. Subjects\\u000a with positive screening results had psychiatric workups. Folate, vitamin\\u000a B(12), and homocysteine blood levels were compared in 278 persons with\\u000a depressive symptoms, including 112 with depressive disorders, and 416\\u000a randomly selected reference

Henning Tiemeier; Tuijl van H. R; J. Meijer; A. J. Kiliaan; M. M. B. Breteler; A. Hofman

2002-01-01

283

Biosynthesis of vitamin B12: concerning the origin of the methine protons of the corrin nucleus  

SciTech Connect

13C NMR spectroscopy has been used to locate six deuterium atoms incorporated biosynthetically on the periphery of the corrin nucleus of vitamin B12 (cyanocobalamin) derived from cells of Propionibacterium shermanii grown in a medium containing 50% /sup 2/H/sub 2/O and /sup 13/C-enriched delta-aminolevulinic acid. The implications of these results for the mechanism of vitamin B12 biosynthesis are discussed, and it is concluded that the same oxidation level of the intermediates is maintained throughout the biosynthetic pathway, from delta-aminolevulinic acid to corrin.

Scott, A.I.; Kajiwara, M.; Santander, P.J.

1987-10-01

284

A child with vitamin B12 deficiency presenting with pancytopenia and hyperpigmentation.  

PubMed

The authors describe a 16-month-old infant presenting with neurologic developmental regression, severe pancytopenia, excessive skin pigmentation, and tremor resulting from nutritional vitamin B12 deficiency. She had been exclusively breast-fed and had refused to take any other food. Laboratory studies showed severe pancytopenia, a decrease in serum B12 levels, and an increase in urinary methylmalonic acid levels. Bone marrow aspiration was compatible with megaloblastic changes. Schilling test was normal. The serum B12 level of the mother was also low. Megaloblastic anemia resulting from inadequate B12 intake was diagnosed. Parenteral B12 therapy was initiated. The neurologic picture did not completely resolve, but pancytopenia, tremor, and hyperpigmentation of the extremities recovered completely. PMID:15591907

Sim?ek, Ozlem Pelin; Gönç, Nazli; Gümrük, Fatma; Cetin, Mualla

2004-12-01

285

Common variants of FUT2 are associated with plasma vitamin B12 levels  

PubMed Central

We identified a strong association (p=5.36×10?17) between rs492602 in FUT2 and plasma vitamin B12 levels in a genome-wide scan (n=1,658) and an independent replication sample (n=1,059) from the Nurses' Health Study. Women homozygous for the rs492602 G allele had higher B12 levels. This allele is in strong linkage disequilibrium with the FUT2 W143X nonsecretor variant, suggesting a plausible mechanism for altered B12 absorption and plasma levels.

Hazra, Aditi; Kraft, Peter; Selhub, Jacob; Giovannucci, Edward L.; Thomas, Gilles; Hoover, Robert N.; Chanock, Stephen J.; Hunter, David J.

2009-01-01

286

Carbon nanotube–chitosan modified disposable pencil graphite electrode for Vitamin B 12 analysis  

Microsoft Academic Search

A single walled carbon nanotube–chitosan (SWCNT–chitosan) modified disposable pencil graphite electrode (PGE) was used in this study for the electrochemical detection of Vitamin B12. Electrochemical behaviors of SWCNT–chitosan PGE and chitosan modified PGE were compared by using cyclic voltammetry (CV), square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques. SWCNT–chitosan modified electrode was also used for the quantification of Vitamin

Filiz Kuralay; Tayfun Vural; Cem Bayram; Emir Baki Denkbas; Serdar Abaci

2011-01-01

287

Vitamin B12 Deprivation in the Rat: Effects on Folate Metabolism with Emphasis on the Nervous System  

Microsoft Academic Search

Rats were subjected to deprivation of vitamin B12 in order to induce neuropathy and to study effects on folate metabolism. Plasma vitamin B12concentrations were maintained at about 100 pg\\/ml for 5 months. Neurological testing failed to reveal signs of neuropathy. Vitamin B12 deprivation induced high plasma folate levels but had no effects on the levels of total folate in the

C. Fehling; M. Jägerstad

1978-01-01

288

TLC-Bioautogram Analysis of Vitamin B12 Compounds from Boiled and Dried Japanese Anchovy (Engraulis japonica) Products  

Microsoft Academic Search

Vitamin B12 contents of boiled and dried Japanese anchovy (Engraulis japonica) products (mild- and semi-dried white bait, and dried whole), which are commercially available in Japan, contained about 3.8 ? 4.6 and 44.6 µg of vitamin B12 per 100 g weight. TLC-bioautogram analysis indicated that the vitamin B12-activity found in each anchovy product was given as a single spot whose Rf value (0.56)

Michiko Nishioka; Fuki Kanosue; Emi Miyamoto; Yukinori Yabuta; Fumio Watanabe

2009-01-01

289

HPLC-ESI-MS analysis of Vitamin B 12 in food products and in multivitamins-multimineral tablets  

Microsoft Academic Search

Methods for the determination of Vitamin B12 remain limited due to their low sensitivity and poor selectivity. In the present work, a simple and sensitive HPLC-ESI-MS method for determining Vitamin B12 in food products and in multivitamin-multimineral tablets was developed. Vitamin B12 was extracted from food products with 50mM sodium acetate buffer (pH 4.0) in the presence of sodium cyanide.

Xubiao Luo; Bo Chen; Li Ding; Fei Tang; Shouzhuo Yao

2006-01-01

290

[A simple health control for the elderly. Screening for vitamin B12 deficiency and thyroid disease].  

PubMed

Screening for vitamin B12 deficiency and thyroid disease is cheap and enables early diagnosis to be made and treatment to be started while it is still simple and can prevent the development of such serious conditions as dementia, depression, or irreversible tissue damage. In 1995-6, 83% (126/151) of all 75-year-olds in Härryda, a district (population 28,500) to the east of Gothenburg, agreed to undergo a health control designed to detect hypo- or hyper-thyroidism or vitamin B12 deficiency among elderly residents without symptoms (or with atypical symptoms not easily recognised). Of the 126 participants, four (3%) had low plasma cobalamin (vitamin B12) levels (a figure similar to or lower than those reported by others), and were treated with vitamin B12 after further examination; eight (6%) had serum thyroid stimulating hormone (TSH) levels below the lower normal limit, though further examination showed all eight to be euthyroid; and two (1.6%) were diagnosed as being hypothyroid (a lower prevalence than figures reported elsewhere), and were treated with laevothyroxine. The findings suggest that such screening might be useful in primary care. However, the clinical diagnosis of vitamin B12 deficiency, and of hypo- or hyperthyroidism, is often difficult, especially in the elderly; and although a low serum TSH level is also considered to be a reliable marker of hyperthyroidism, like others this study showed that it may occur even in the absence of disease. Thus, serum TSH and plasma B12 levels are useful screening variables, but need to be complemented by other tests before diagnosis is set. PMID:9424529

Bondeson, E; Meisel, T; Eggertsen, R

1997-11-19

291

STM investigations of Au(1 1 1) electrodes coated with vitamin B12 derivatives  

NASA Astrophysics Data System (ADS)

Vitamin B12 derivatives immobilized at flame-annealed Au(1 1 1) electrode surfaces have been investigated in close correlation with their structural properties and spatial arrangement at the electrode substrate by scanning tunneling microscopy (STM) in air and in aqueous 0.1 M NaClO4 solution. The investigated compounds were symmetrical (B12C10S SC10B12) and nonsymmetrical (B12C10S SC10) dialkyl disulfide derivatives of vitamin B12, attached to the electrode surfaces by the S Au bond. The ex situ and in situ STM experiments show the formation of a surface layer, whose packing density and structure is presumably controlled by the spatial arrangement of the large cobyrinate head groups. In presence of the symmetrical B12 compound, a disordered surface layer is observed. Voltammetric investigations show that, in 0.1 M NaClO4, this layer becomes unstable at potentials approximately ? -1000 mV vs. MSE and is almost completely removed at more negative potentials. The STM imaging properties of the nonsymmetrical B12 surface layer show a significant dependence on the tunneling distance. In particular, at small tunneling distances, a highly regular hexagonal surface pattern is observed that suggests strongly the presence of an ordered surface assembly. Modeling of the B12 head group has been performed to provide information for a structure-related interpretation of the high-resolution STM images. The investigations are first STM results obtained at such B12 modified electrodes.

Sz?cs, E.; Durrer, L.; Luginbühl, R.; Simic, N.; Viana, A. S.; Abrantes, L. M.; Keese, R.; Siegenthaler, H.

2006-01-01

292

[Folate and vitamin B12 deficiency. Characterization of parameters for early diagnosis].  

PubMed

True vitamin B12/folate deficiency is more common than is currently appreciated; it appears in many guises and the classic hematological features of megaloblastic anaemia are often absent. The single most reliable predictor of megaloblastic anaemia is serum vitamin B12/folate concentration, but this determination in a screening program for all patients is difficult in terms of laboratory overload and cost. Early recognition of nutritional anaemias is, however, mandatory and we undertook this study to explore the possibility of identifying, on a demographic basis or because of routine laboratory results, a group of subjects at risk for vitamin B12/folate deficiency. Results obtained in simultaneous radioassay of serum B12 and folate levels and erythrocyte folate concentration in 1.200 hospitalized patients are presented. Coexisting iron deficiency was excluded by ferritin assay. We found no significant difference between males and females and no correlation between serum folate and B12 concentrations and aging. Low serum folic and cobalamin levels were found in 53% of patients with macrocytosis and elevated MCH, even in the absence of anaemia. These observations suggest that increased MCV and MCH may be present before a related anaemia and that serum folate and cobalamin levels must be monitored early in these patients to prevent a deficiency. PMID:2602638

Tarocco, R P; Faro, G; Sargiotto, A; Ansermin, A

1989-10-01

293

Dual isotope Schilling test for measuring absorption of food-bound and free vitamin B12 simultaneously  

Microsoft Academic Search

A prototype food-bound vitamin B12 (food-B12) absorption test has been developed in which ⁵⁷Co-B12 was incorporated in vitro into egg yolk (yolk-B12) and served to volunteers in 50-g cooked portions together with toast and coffee for breakfast. Six hours later, 1 mg nonlabeled B12 was given intramuscularly and 24-hour urine was collected for radioactivity measurement. In separate tests, the absorption

A. Doscherholmen; S. Silvis; J. McMahon

1983-01-01

294

Review of the magnitude of folate and vitamin B12 deficiencies worldwide  

Technology Transfer Automated Retrieval System (TEKTRAN)

Human deficiencies of folate and vitamin B12 result in adverse effects which may be of public health significance, but the magnitude of these deficiencies is unknown. Therefore, we examine the prevalence data currently available, assess global coverage of surveys, determine the frequency with which...

295

Two new species of arthrobacter requiring respectively vitamin B 12 and the terregens factor  

Microsoft Academic Search

The morphological, cultural, nutritional and general physiological properties of two species of bacteria, isolated from soil, are described which require for growth vitamin B12 and the terregens factor respectively. Both organisms undergo the change in morphology from a rod stage in young culture to a coccoid stage in older culture which is characteristic of members of the genus ArthrobacterConn and

A. G. Lochhead

1958-01-01

296

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

297

Ultrasonographic evaluation to diagnose hepatic lipidosis in Egyptian Zaraibi goats with vitamin B12 deficiency  

Microsoft Academic Search

As little is known about the ultrasonographic features of hepatic lipidosis (white liver disease) in goats, this study was undertaken to evaluate the use of ultrasound for the diagnosis of hepatic lipidosis associated with vitamin B12 (cyanocobalamin) deficiency in Egyptian Zaraibi goats. A total of 38 goats (28 with weight loss, diarrhoea and anaemia and 10 clinically healthy) were studied.

Sabry A. El-Khodery; Hussein S. Hussein; Mohamed E. El-Boshy; Medhat N. Nassif

2011-01-01

298

Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization  

Microsoft Academic Search

BACKGROUND: Nickel (Ni) and cobalt (Co) are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited. RESULTS: We carried out comparative genomic

Yan Zhang; Dmitry A Rodionov; Mikhail S Gelfand; Vadim N Gladyshev

2009-01-01

299

Rare sensory and autonomic disturbances associated with vitamin B12 deficiency  

Microsoft Academic Search

Vitamin B12 deficiency is an important nutritional disorder causing neurological manifestations of myelopathy, neuropathy and dementia. Sub-acute combined degeneration (SCD) with involvement of the posterior columns in the cervical and thoracic cord is a common presentation of this disorder. In this case report, we describe a 43year old woman with pernicious anemia and myelopathy with atypical clinical features. The patient

Preeti Puntambekar; Maysaa M. Basha; Imad T. Zak; Ramesh Madhavan

2009-01-01

300

Paralysis of Upward Gaze as a Presenting Symptom of Vitamin B12 Deficiency  

Microsoft Academic Search

A 47-year-old woman presented with paralysis of upward gaze associated with Addison’s pernicious anaemia. Administration of cyanocobalamin resulted in significant improvement of eye movements and haematological parameters. Isolated paralysis of upward gaze may be a feature of vitamin B12 deficiency.Copyright © 1984 S. Karger AG, Basel

R. Sandyk

1984-01-01

301

Inverse Correlation of Low Vitamin B12, Folic Acid and Homocysteine Levels in Diabetic Retinopathy  

Microsoft Academic Search

Purpose: Evaluation of total plasma homocysteine, serum vitamin B12 and folic acid levels in patients with diabetic retinopathy. Materials and Methods: Fifty patients having insulin dependent diabetes mellitus were included and subdivided into 3 groups: Diabetics without retinopathy (n=10), with background retinopathy (n=20), and proliferative retinopathy (n=20). Ten nor- mal subjects served as controls. Plasma total homocysteine levels were measured

Soher A. Mohammed Ismail; Iman A. Fahmy; Samah Ali; Mostafa Farrag

302

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

303

Nutritional vitamin B 12 deficiency: Two cases detected by routine newborn urinary screening  

Microsoft Academic Search

We describe two asymptomatic newborns with nutritional vitamin B12 deficiency in whom increased urinary methylmalonic acid was detected by routine neonatal screening at 3 weeks of age. Both infants were exclusively breast-fed. One mother suffered from pernicious anaemia, and the other was a strict vegetarian. Both mothers had no clinical or haematological abnormality, aside from a borderline mean corpuscular volume

J. L. Michaud; B. Lemieux; H. Ogier; M. A. Lambert

1992-01-01

304

The structural basis for molecular recognition by the vitamin B 12 RNA aptamer  

Microsoft Academic Search

Previous solution structures of ligand-binding RNA aptamers have shown that molecular recognition is achieved by the folding of an initially unstructured RNA around its cognate ligand, coupling the processes of RNA folding and binding. The 3 Å crystal structure of the cyanocobalamin (vitamin B12) aptamer reported here suggests a different approach to molecular recognition in which elements of RNA secondary

Jay C. Nix; Django Sussman; Charles Wilson

2000-01-01

305

Total serum homocysteine as an indicator of vitamin B12 and folate status  

SciTech Connect

Presented is a modification of an assay for total serum homocysteine (Hcy) in which the Hcy plus radioactive adenosine is converted enzymatically to labeled S-adenosylhomocysteine (AdoHcy). The modifications included a commerical source for the AdoHcy hydrolase, adenosine labeled with either /sup 14/C or /sup 3/H, and separation of the AdoHcy by thin layer chromatography. The assay was sensitive to 25 pmol. Hcy levels in sera from 18 controls ranged from 6.9 to 12.1 mumol/L with a mean of 9.1 and a SD of 1.5 mumol/L. The total serum Hcy was increased in vitamin B12 and folate deficiency. The level was high in congenital defects of vitamin B12 metabolism, blocking the methylation of Hcy regardless of the serum vitamin B12 levels, but was normal in the absence of tissue deficiency even if the serum vitamin B12 levels were low. The procedure has been found practical in two years of use and requires only 0.1 mL of serum.

Chu, R.C.; Hall, C.A.

1988-10-01

306

Vitamin B 12 production and depletion in a naturally occurring eutrophic lake.  

PubMed

The distribution of vitamin B(12) within Upper Klamath Lake was surveyed at approximately monthly intervals during a period from September 1968 to November 1969. High concentrations (up to 1.8 mug/g of dry sediment) characteristically occurred at the water-sediment interface, with a sharp decline below this area. A heavy bloom of Aphanizomenon flos-aquae occurred from the latter part of May through October 1969. B(12) concentrations of the uppermost sediments, from all but one sampling site, increased gradually through the bloom, followed by a drastic increase during the die-off period. B(12) is probably not a limiting factor for primary productivity, since sufficient levels of this vitamin were found to occur throughout the year. Of 42 cultures isolated from Upper Klamath Lake water and sediments, 20 were found capable of producing 50 pg or more of B(12)/ml of medium. Phytoplankton samples were found to contain up to 5 mug of B(12)/g of dry material. Degradation of B(12) occurred in sterilized as well as fresh sediment samples. PMID:4622828

Gillespie, P A; Morita, R Y

1972-02-01

307

Opening and closing motions in the periplasmic vitamin B12 binding protein BtuF.  

PubMed

BtuF is the periplasmic binding protein (PBP) in the vitamin B(12) uptake system in Escherichia coli where it is associated with the ABC transporter BtuCD. When the ligand binds, PBPs generally display large conformational changes, commonly termed the Venus flytrap mechanism. BtuF belongs to a group of PBPs that, on the basis of crystal structures, does not appear to display such behavior. Using 480 ns multicopy molecular dynamics simulations of apo and holo forms of the protein, we investigate the dynamics of BtuF. We find BtuF to be more flexible than previously assumed, displaying clear opening and closing motions which are more pronounced in the apo form. The protein behavior is compatible with a PBP functional model that postulates a closed conformation for the ligand-bound state, whereas the empty form fluctuates between open and closed conformations. Elastic network normal-mode analysis suggests that all BtuF-like PBPs are capable of similar opening and closing motions. It also makes the typical Venus flytrap domain motions a likely common means of how PBP-ABC transporter interaction could occur. PMID:17073449

Kandt, Christian; Xu, Zhitao; Tieleman, D Peter

2006-11-01

308

Should we monitor vitamin B12 and folate levels in Crohn's disease patients?  

PubMed

Abstract Objective. Crohn's disease commonly involves the small intestine, which is the site of vitamin B12 and folate absorption. Our aim was to define the prevalence of vitamin B12 and folate deficiency in patients with Crohn's disease and to identify predictive factors associated with such abnormalities. Methods. Two years prospective study of 180 consecutive Crohn's disease patients. Vitamin B12 and folate deficiency was defined as serum levels below 200 pg/ml and 3 ng/ml, respectively. We analysed prevalence of these deficiencies and possible predictive factors including small intestine resection, disease location, activity and duration of disease. Controls were ulcerative colitis patients (n = 70). Results. The prevalence of B12 deficiency in Crohn's disease was 15.6% (95%CI 9.7-20%) compared with 2.8% (95%CI 0.8-9.8%) in ulcerative colitis (p = 0.007). With regard to folate deficiency, the prevalence in patients with Crohn's disease was 22.2% (95%CI 16-28%) compared with 4.3% (95%CI 1.4-12%) in ulcerative colitis (p = 0.001); 7.8% of Crohn's disease patients had macrocytic anemia. Ileal resection was found to be a risk factor for B12 deficiency (OR 2.7; 1.2-6.7; p = 0.02), and disease activity a risk factor for folate deficiency (OR 2.4; 1.2-5.1; p = 0.01). Conclusion. A significant proportion of patients with Crohn's disease suffer from vitamin B12 and/or folate deficiency, suggesting that regular screening should be performed, with closer monitoring in patients with ileal resection or active disease. PMID:24063425

Bermejo, Fernando; Algaba, Alicia; Guerra, Iván; Chaparro, María; De-La-Poza, Gema; Valer, Paz; Piqueras, Belén; Bermejo, Andrea; García-Alonso, Javier; Pérez, María-José; Gisbert, Javier P

2013-09-25

309

Insights into the evolution of vitamin B12 auxotrophy from sequenced algal genomes.  

PubMed

Vitamin B(12) (cobalamin) is a dietary requirement for humans because it is an essential cofactor for two enzymes, methylmalonyl-CoA mutase and methionine synthase (METH). Land plants and fungi neither synthesize or require cobalamin because they do not contain methylmalonyl-CoA mutase, and have an alternative B(12)-independent methionine synthase (METE). Within the algal kingdom, approximately half of all microalgal species need the vitamin as a growth supplement, but there is no phylogenetic relationship between these species, suggesting that the auxotrophy arose multiple times through evolution. We set out to determine the underlying cellular mechanisms for this observation by investigating elements of B(12) metabolism in the sequenced genomes of 15 different algal species, with representatives of the red, green, and brown algae, diatoms, and coccolithophores, including both macro- and microalgae, and from marine and freshwater environments. From this analysis, together with growth assays, we found a strong correlation between the absence of a functional METE gene and B(12) auxotrophy. The presence of a METE unitary pseudogene in the B(12)-dependent green algae Volvox carteri and Gonium pectorale, relatives of the B(12)-independent Chlamydomonas reinhardtii, suggest that B(12) dependence evolved recently in these lineages. In both C. reinhardtii and the diatom Phaeodactylum tricornutum, growth in the presence of cobalamin leads to repression of METE transcription, providing a mechanism for gene loss. Thus varying environmental conditions are likely to have been the reason for the multiple independent origins of B(12) auxotrophy in these organisms. Because the ultimate source of cobalamin is from prokaryotes, the selective loss of METE in different algal lineages will have had important physiological and ecological consequences for these organisms in terms of their dependence on bacteria. PMID:21551270

Helliwell, Katherine E; Wheeler, Glen L; Leptos, Kyriacos C; Goldstein, Raymond E; Smith, Alison G

2011-05-06

310

Relations of vitamin B12, vitamin B6, folate, and homocysteine to cognitive performance in the Normative Aging Study1  

Microsoft Academic Search

We investigated the relations between plasma concentrations of homocysteine and vitamins B- 12 and B-6 and folate, and scores from a battery of cognitive tests for 70 male subjects, aged 54-81 y, in the Normative Aging Study. Lower concentrations of vitamin B-l2 (P = 0.04) and folate (P = 0.003) and higher concentrations of homocysteine (P = 0.0009) were associated

Karen M Riggs; Avron Spiro Ill; Katherine Tucker; David Rush

311

Effect of calcium deficiency on vitamin B12 absorption in rats.  

PubMed

The influence of calcium on vitamin B12 absorption was investigated in two experiments. In the first we investigated whether B12 malabsorption in rats with biliary diversion through choledochocolic fistula is caused by deficiency of calcium in the small intestine. Calcium concentrations were measured in 10 fistula- and 10 sham-operated rats. Fistula rats had steatorrhea, but the concentration of calcium in the intestinal lumen was increased. In the second experiment we studied the effect of calcium deficiency on B12 absorption. Ten young rats were fed a low-calcium diet and 10 rats a control diet for 4 weeks. Rats on the low-calcium diet had moderately reduced calcium concentration in the blood and in the intestinal juice but unaltered calcium concentration in the cytosol fraction of intestinal mucosal scrapings. The absorption of 57CoB12 was unimpaired. This suggests that moderate calcium deficiency does not influence the intestinal absorption of vitamin B12 in the rat. PMID:2320946

Bergesen, O; Schjønsby, H; Schjerven, L

1990-03-01

312

Enhanced therapeutic effect of methotrexate in experimental rat leukemia after inactivation of cobalamin (vitamin B12) by nitrous oxide  

Microsoft Academic Search

Exposure to nitrous oxide interferes selectively with the coenzyme function of vitamin B12 and causes inactivation of methionine synthetase, with subsequent impairment of folate metabolism and reduction of cellular proliferation. In a rat leukemia model (BNML) we investigated the combined administration of nitrous oxide, inactivating vitamin B12, and methotrexate (MTX), a folate antagonist inhibiting the enzyme dihydrofolate reductase. Through different

A. C. M. Kroes; J. Lindemans; M. Schoester; J. Abels

1986-01-01

313

Masked deficit of vitamin B12 in the patient with heterozygous b-thalassemia and spastic paraparesis  

Microsoft Academic Search

The spinal cord, brain, optic nerves and peripheral nerves may be affected by vitamin B12 (cobalamin) deficiency. Deficiency of vitamin B12 also causes megaloblastic anaemia, meaning that the red blood cells are usually larger than normal. In this paper we report a 16-year old girl who was referred to us for the evaluation of mild paraparesis and paresthesias marked by

Ernest BILIC; Ervina BILIC; Marija ZAGAR; Stjepan JURIC

2004-01-01

314

TwoRadioassays forSerumVitamin B12andFolateDetermination Compared ina Reference Interval Study  

Microsoft Academic Search

lationbetween the folate (r = 0.87) andvitaminB12(r = 0.94) kits, we observedsignificantdifferencesin the overall mean values for vitamin B12(p <0.01) and folate (p <0.001) as measuredwith the kits in this population.Radioassaystan- dard-curvedata for the folate assayswere similar,butthese data indicated greater sensitivityat low concentrations for one vitaminB12kitthan the other. Using reference intervals recommendedinthe kit inserts,we foundthat the vitaminB12 statusfor 9% of

Robert H. Christenson; Georgette A. Dent

315

Autonomic dysfunction in vitamin B12 deficiency: A heart rate variability study  

Microsoft Academic Search

This study was arranged to examine whether vitamin B12 deficiency may cause autonomic dysfunction. Time-domain and long-term frequency-domain heart rate variability parameters from 12 patients with pernicious anemia were compared to 12 age and sex matched controls. In B12 deficient patient group time-domain parameters; SDNN (100.4±37.86 vs. 131.91±26.94, P=0.05), SDANN (87.00±37.77 vs. 118.83±26.22, P=0.05) SD (39.41±13.32 vs. 53.41±15.39, P=0.0221), rMSSD

Ahmet Bilge Sözen; ?eref Demirel; Vakur Akkaya; Hasan Kudat; Tufan Tükek; Mustafa Yeneral; Mustafa Özcan; Özen Güven; Ferruh Korkut

1998-01-01

316

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.

2012-01-01

317

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

318

Vitamin B12 and folate concentrations in serum and cerebrospinal fluid of neurological patients with special reference to multiple sclerosis and dementia  

Microsoft Academic Search

Vitamin B12 and folate concentrations were measured in serum and cerebrospinal fluid (CSF) in 293 neurological patients. Serum and CSF vitamin B12 concentrations showed a positive correlation. In individual patients CSF B12 concentrations varied considerably for a given serum concentration. The median serum vitamin B12 concentration of the Alzheimer's type dementia group was significantly lower compared with that of a

T Q Nijst; R A Wevers; H C Schoonderwaldt; O R Hommes; A F de Haan

1990-01-01

319

Cellular folate vitamer distribution during and after correction of vitamin B12 deficiency: a case for the methylfolate trap  

Microsoft Academic Search

Haematological sequellae of vitamin B12 deficiency are attributed to disturbed DNA synthesis, but vitamin B12 itself plays no role in DNA biosynthesis. A proposed explanation for this is the methylfolate trap hypothesis. This hypothesis states that B12 deficiency impairs overall folate metabolism because 5-methyltetrahydrofolate (5MTHF) becomes metabolically trapped. This trap results from the fact that 5MTHF can neither be metabolised

Y. M. Smulders; D. E. C. Smith; R. M. Kok; T. Teerlink; D. W. Swinkels; C. D. A. Stehouwer; C. Jakobs

2006-01-01

320

Clinical and laboratory features and response to treatment in patients presenting with vitamin B12 deficiency-related neurological syndromes  

Microsoft Academic Search

Aims and objectives: To study the clinical and laboratory features of patients admitted with vitamin B12 deficiency-re- lated (B12def) neurological syndromes. Settings and Design: A hospital-based retrospective and prospective study con- ducted at a referral teaching hospital. Materials and Meth- ods: Consecutive patients admitted with vitamin B12 defi- ciency-related neurological disorders during a three-year pe- riod from June 2000 to

Sudhir Kumar; J Vijayan; J Jacob; M Alexander; C Gnanamuthu; S Aaron

2005-01-01

321

Vitamin B12 and folate bioavailability from two prenatal multivitamin/multimineral supplements.  

PubMed

In this crossover, single-blind study, the bioavailability of B12 and folate, fasting and postprandially, was measured in 30 pregnant women for two prenatal multivitamin/multimineral supplements (Stuartnatal Plus and Materna, Wyeth-Ayerst Pharmaceuticals, Philadelphia, PA) and a placebo. Blood samples were obtained before supplementation and at 1, 3, 6, and 8 hr after supplementation serum levels of the two vitamins were measured by radioimmunoassay. The maximum postabsorption serum level was multiplied by the total body plasma levels to obtain the total rate of body absorption. The absorption peak of both vitamins occurred at 3 hours after ingestion of a supplement. The total body absorption of the two vitamins was greater during fasting than it was postprandially. There was 30% greater B12 absorption for Stuartnatal Plus (371 +/- 56 vs. 285 +/- 34 pmol) and 33% for Materna (315 +/- 34 vs. 236 +/- 4 pmol, p < or = 0.05). Similarly, there was 117% greater folate absorption fasting for Stuartnatal Plus (163 +/- 15 vs. 75 +/- 15 nmol, p < or = 0.001) and 57% greater absorption for Materna (207 +/- 21 vs. 132 +/- 13 nmol, p < or = 0.01). Both vitamins were readily absorbed (within 3 hours) into the maternal hepatic portal circulation. The absorption of both vitamins was significantly less when ingested after the test meal than when fasting. PMID:11041441

Dawson, E B; Evans, D R; Conway, M E; McGanity, W J

2000-01-01

322

Theoretical analysis of electronic absorption spectra of vitamin B12 models  

NASA Astrophysics Data System (ADS)

Time-dependent density-functional theory (TD-DFT) is applied to analyze the electronic absorption spectra of vitamin B12. To accomplish this two model systems were considered: CN-[CoIII-corrin]-CN (dicyanocobinamide, DCC) and imidazole-[CoIII-corrin]-CN (cyanocobalamin, ImCC). For both models 30 lowest excited states were calculated together with transition dipole moments. When the results of TD-DFT calculations were directly compared with experiment it was found that the theoretical values systematically overestimate experimental data by approximately 0.5 eV. The uniform adjustment of the calculated transition energies allowed detailed analysis of electronic absorption spectra of vitamin B12 models. All absorption bands in spectral range 2.0-5.0 eV were readily assigned. In particular, TD-DFT calculations were able to explain the origin of the shift of the lowest absorption band caused by replacement of the-CN axial ligand by imidazole.

Andruniow, Tadeusz; Kozlowski, Pawel M.; Zgierski, Marek Z.

2001-10-01

323

Effects of Orotic Acid on Coenzyme A and Pantothenic Acid of Liver in Vitamin B12 Deficiency  

Microsoft Academic Search

OROTIC ACID was found to reduce the vitamin B12 requirement for growth and for the betaine-homocysteine transmethylase activity of liver in rats fed corn\\/soybean meal ration deficient in vitamin B121. These results suggested a metabolic relationship between orotic acid and vitamin B12. To ascertain whether this metabolic relationship was limited or more extended, we have directed our research towards other

G. Moruzzi; R. Viviani; M. Marchetti; F. Sanguinetti

1958-01-01

324

Brain function in the elderly: role of vitamin B 12 and folate  

Microsoft Academic Search

Vitamin B12 (cobalamin) deficiency associated neuropathy, originally called sub- acute combined degeneration, is particularly common in the elderly. The potential danger today is that with supplementation with folic acid of dietary staples such as flour, that the incidence of this disease could rise as folic acid, as opposed to natural folate (NsCH3HFGIu,), enters the cell and the metabolic cycle by

Donald G. Weir; John M. Scott

1999-01-01

325

Production of extracellular vitamin B12 compounds from methanol by Methanosarcina barkeri  

Microsoft Academic Search

Summary  Production of vitamin B-12 compounds from methanol was carried out by Methanosarcina barkeri Fusaro, an anaerobic methanogen. The methanogen released about 40% to 70% of corrinoids irrespective of the culture medium\\u000a used. The use of cysteine instead of Na2S as the sole sulphur source for cell growth led to an increase in the cobalt chloride concentration in the culture medium

Tapan Kumar Mazumder; Naomichi Nishio; Satoshi Fukuzaki; Shiro Nagai

1987-01-01

326

Oral cyanocobalamin supplementation in older people with vitamin B12 deficiency: a dose-finding trial  

Microsoft Academic Search

BACKGROUND: Supplementation with high doses of oral cobalamin is as effective as cobalamin administered by intramuscular injection to correct plasma markers of vitamin B(12) deficiency, but the effects of lower oral doses of cobalamin on such markers are uncertain. METHODS: We conducted a randomized, parallel-group, double-blind, dose-finding trial to determine the lowest oral dose of cyanocobalamin required to normalize biochemical

S. J. P. M. Eussen; L. C. de Groot; R. Clarke; J. Schneede; P. M. Ueland; W. H. L. Hoefnagels; W. A. van Staveren

2005-01-01

327

Ultrafast electronic relaxation of excited state vitamin B 12 in the gas phase  

NASA Astrophysics Data System (ADS)

The time evolution of electronically excited vitamin B 12 (cyanocobalamin) has been observed for the first time in the gas phase. It reveals an ultrafast decay to a state corresponding to metal excitation. This decay is interpreted as resulting from a ring to metal electron transfer. This opens the observation of the excited state of other complex biomimetic systems in the gas phase, the key to the characterisation of their complex evolution through excited electronic states.

Shafizadeh, Niloufar; Poisson, Lionel; Soep, Beno?ˆt

2008-06-01

328

Effective oral delivery of insulin in animal models using vitamin B12-coated dextran nanoparticles  

Microsoft Academic Search

The potential utility of vitamin B12 carrier system for the oral delivery of conjugated peptides\\/proteins and enhancement of nanoparticles (NPs) transport has been demonstrated. The present study aims to optimize the effectiveness of VB12–NPs conjugates using different levels of cross-linking, linked with different VB12-coatings and evaluates in animal models to investigate an efficient insulin carrier. Amino alkyl VB12 derivatives suitable

Kishore B. Chalasani; Gregory J. Russell-Jones; Akhlesh K. Jain; Prakash V. Diwan; Sanjay K. Jain

2007-01-01

329

[Sensitivity of Sherman's propionic acid bacilli to antibacterial preparations and vitamin B12 synthesis].  

PubMed

Sherman propionic acid bacilli were sensitive to benzylpenicillin, ampicillin, ceporin, tetracyclines, oleandomycin, oletetrin, tetraolean, sigmamycin, levomycetin and furadonine. Methicillin, oxacillin, monomycin, kanamycin, polymyxin and furazolidone had an insignificant effect on the above organism. The subbacteriostatic concentrations of methicillin, oxacillin, streptomycin, monomycin, kanamycin, neomycin, tetraolean, sigmamycin, polymyxin M and ristomycin increased the biosynthesis of vitamin B12 by Sherman propionic acid bacilli, while benzylpenicillin, ampicillin, tetracyclines, oleandomycin, oletetrin, levomycetin and furadonine in the subbacteriostatic concentrations inhibited this process. PMID:596839

Sidorchuk, I I

1977-11-01

330

Vitamin B 12 Deficiency Stimulates Osteoclastogenesis via Increased Homocysteine and Methylmalonic Acid  

Microsoft Academic Search

The risk of nutrient deficiencies increases with age in our modern Western society, and vitamin B12 deficiency is especially prevalent in the elderly and causes increased homocysteine (Hcy) and methylmalonic acid (MMA) levels.\\u000a These three factors have been recognized as risk factors for reduced bone mineral density and increased fracture risk, though\\u000a mechanistic evidence is still lacking. In the present

Bart L. T. Vaes; Carolien Lute; Henk J. Blom; Nathalie Bravenboer; Teun J. de Vries; Vincent Everts; Rosalie A. Dhonukshe-Rutten; Michael Müller; Lisette C. P. G. M. de Groot; Wilma T. Steegenga

2009-01-01

331

Liver copper, selenium and vitamin B12 concentrations in farmed and feral red deer (Cervus elaphus)  

Microsoft Academic Search

AIM: To compare liver copper, selenium and vitamin B12 concentrations in red deer of farmed and feral origin.METHODS: Liver samples were collected from red deer at a South Island deer slaughter premise and a game packing house in November 2000. The site of origin and age of each animal were recorded. A subsample of 107 livers was selected (n=5-10 per

SG Tremain-Boon; JCA Hart; PR Wilson; N Lopez-Villalobos

2002-01-01

332

Subcellular localisation of vitamin B12 during absorption in the guinea-pig ileum  

Microsoft Academic Search

The subcellular distribution of vitamin B12 was studied during its absorption in the guinea-pig ileum. Animals were fed either (57Co) or (58Co) cyanocobalamin and killed two or four hours later. At two hours labelled cyanocobalamin was concentrated in brush border and lysosomal fractions of ileal homogenates, with some remaining in the sample layer. In contrast, at four hours labelled cyanocobalamin

W J Jenkins; R Empson; D P Jewell; K B Taylor

1981-01-01

333

Protein Synthesis in Megaloblastic Erythropoiesis caused by Vitamin B12 Deficiency  

Microsoft Academic Search

LITTLE information is available about protein synthesis in the megaloblasts of pernicious anaemia. In experimental animals deprived of vitamin B12, however, depressed protein synthesis has been demonstrated both in vivo1 and in cell cultures and cell free systems derived from deficient animals1-3. The addition of cobamide co-enzymes to such in vitro systems enhances the incorporation of labelled amino-acids into proteins2,3,

S. N. Wickramasinghe; D. G. Chalmers

1968-01-01

334

A teased-fibre study of the median nerves of vitamin B12-depleted baboons.  

PubMed Central

Isolated nerve fibres of the median nerve of normal baboons and baboons kept on diets deficient in vitamin B12, and supplemented with potassium cyanide and potassium thiocyanate injections, were examined by the teased-fibre technique. Regression lines of internodal length on fibre diameter were obtained. Small differences between the groups were apparent but were of uncertain significance. There was occasional evidence of segmental demyelination and Wallerian degeneration but this was not characteristic of any particular group.

Knowles, J F

1978-01-01

335

Increased risk of vitamin B12 and iron deficiency in infants on macrobiotic diets  

Microsoft Academic Search

The blood iron, vitamin B-12, and folate status ofthe 1985 birth cohort of Dutch infants aged 10. 1-20.4 mo fed macrobiotic diets (n = 50) and matched omnivorous control infants (n = 57) was measured. Fe deficiency (combination of Hb < 120 gIL, ferritin < 12 ??g\\/L, and FEP > 1.77 ?tmol\\/L) was observed in 15% ofthe macrobiotic group but

Pieter C Dagnelie; Staveren van W. A; Freddy JVRA Vergote; Pieter G Dingjan; Berg van den H; J. G. A. J. Hautvast

1989-01-01

336

Failure of Menadione to affect Folate Utilization in Vitamin B12-deficient Human Beings  

Microsoft Academic Search

IT has been suggested that vitamin B12-deficiency in man may produce a defect in folate utilization due to trapping of L. casei folate activity1. This suggestion has recently received support in the British literature2. The trapped folate is probably some form of N-5-methyltetrahydrofolic acid3. Donaldson and Keresztesy4 reported that N-5-methyltetrahydrofolic acid can be enzymatically oxidized to N-5,10-methylene-tetrahydrofolic acid in the

Victor Herbert; Richard R. Streiff; Louis W. Sullivan; Morris Friedkin

1964-01-01

337

Increased Plasma Methylmalonic Acid Level Does Not Predict Clinical Manifestations of Vitamin B12 Deficiency  

Microsoft Academic Search

Background: The prevalence of vitamin B12 defi- ciency, defined as an elevated concentration of plasma methylmalonic acid (P-MMA), has been estimated to be 15% to 44% in the elderly. However, we do not know whether an increased P-MMA level actually indicates or predicts a clinical condition in need of treatment. Participants and Methods: In a follow-up study, 432 individuals not

Anne-Mette Hvas; Jørgen Ellegaard; Ebba Nexø

2001-01-01

338

Approaches to vitamin B12 deficiency. Early treatment may prevent devastating complications.  

PubMed

Vitamin B12 deficiency is a common problem that affects the general population and the elderly in particular. Persons with the deficiency may be asymptomatic or may have hematologic or neuropsychiatric signs and symptoms. If the disorder is untreated, complications may cause significant morbidity. In this article, Drs Dharmarajan and Norkus discuss approaches to screening and diagnosis as well as the nontoxic, low-cost treatments now available. PMID:11467046

Dharmarajan, T S; Norkus, E P

2001-07-01

339

Dual pathology as a result of spinal stenosis and vitamin B12 deficiency  

Microsoft Academic Search

Vitamin B12 deficiency can confound the clinical assessment of patients presenting with features of spinal disorders. Speciality\\u000a practice within spinal surgery may lead the clinician to a focus upon spinal explanations for symptoms and that belief may\\u000a be reinforced by supporting imaging. In the presence of mainly sensory symptoms consideration and exclusion of non surgical\\u000a causes needs to occur. This

Mohammed Shakil Patel; Zurqa Rasul; Philip Sell

340

Folate, vitamin B12 and total homocysteine levels in neonates from Brazil  

Microsoft Academic Search

Objective:To determine folates, vitamin B12 and total homocysteine levels among neonates from mothers of low or high socioeconomic status.Design:We carried out a cross-sectional transversal study comprising 143 neonates from two maternity hospitals in the city of Salvador, Northeast of Brazil. Cord blood samples were obtained at the time of delivery from newborns from low (group 1, n=77) or high (group

F D Couto; L M O Moreira; D B dos Santos; M G Reis; M S Gonçalves

2007-01-01

341

Hyperhomocysteinemia, and low intakes of folic acid and vitamin B12 in urban North India  

Microsoft Academic Search

Summary  \\u000a Background and Aim An adverse coronary risk profile has been reported amongst rural-to-urban migrant population living in urban slums undergoing\\u000a stressful socio-economic transition. These individuals are likely to have low intakes of folic acid and vitamin B12, which\\u000a may have an adverse impact on serum levels of homocysteine (Hcy). To test this hypothesis, we studied serum levels of Hcy

Anoop Misra; Naval K. Vikram; R. M. Pandey; Manjari Dwivedi; Faiz Uddin Ahmad; Kalpana Luthra; Kajal Jain; Nidhi Khanna; J. Rama Devi; Rekha Sharma; Randeep Guleria

2002-01-01

342

Determination of Vitamin B12 in Multivitamin Tablets by High Performance Liquid Chromatography  

Microsoft Academic Search

Two procedures for separation and determination of vitamin B12 in multivitamin tablets by reversed phase high performance liquid chromatography are proposed. Sample preparation is very simple: tablets are dissolved in distilled water, centrifuged and filtered. The sample solution is directly applied in the sample loop injector and chromatograms are obtained with gradient elution using water-methanol and water-acetonitrile as solvents. The

Marina Stefova; Trajce Stafilov; Kiro Stojanoski; Biljana Cepreganova-Krstic

1997-01-01

343

Serum Levels of Zinc, Copper, Vitamin B12, Folate and Immunoglobulins in Individuals with Giardiasis  

PubMed Central

Background: Giardia lamblia is one of the most important intestinal parasites. The aim of this study was to measure serum levels of IgA, IgE, zinc, copper, vitamin B12 and folate in individuals with giardiasis in comparison to normal subjects. Methods: The study was carried out among 49 Giardia positive and 39 age and sex matched healthy volunteers. Examination of stool samples was done by direct wet smear and formol-ether concentration method. Serum samples were obtained for further laboratory examination. IgA levels were measured by Single Radial Immune Diffusion (SRID). IgE levels were measured by ELISA kit. Zinc and copper levels was measured by Ziestchem Diagnostics Kit and colorimetric endpoint-method respectively. Vitamin B12 and folate levels were measured by DRG Diagnostics Kit and Enzyme Immunoassay method respectively. All data were analyzed using SPSS version 17. Results: There was a statistically significant difference in IgA, IgE, copper and zinc levels between positive and negative groups (P<0.05). There was no significant difference between vitamin B12 and folate levels between the two groups. Mean values of Giardia positive and negative groups for IgA were 309.26 and 216.89 mg/dl, IgE 167.34 and 35.49 IU/ml, copper 309.74 and 253.61 ?g/dl and zinc 69.41 and 144.75 ?g/dl respectively. Conclusion: The results showed levels of IgA may correlate more closely with giardiasis than IgE. Regarding trace elements, giardiasis elevated serum copper levels, while it decreased serum zinc. Finally, there was no significant difference in serum levels of vitamin B12 and folic acid between the two groups.

Zarebavani, M; Dargahi, D; Einollahi, N; Dashti, N; Mohebali, M; Rezaeian, M

2012-01-01

344

Effect of Vitamin B 12 and Folate on Homocysteine levels in colorectal cancer  

Microsoft Academic Search

Folate and cobalamin (Vitamin B12) are two essential micronutrients involved in one-carbon metabolism, which affects heart disease, neural tube defects and\\u000a cancer. Methylenetetrahydrofolate reductase, the key enzyme involved in one carbon metabolism produces methyl tetrahydrofolate\\u000a from methylene tetrahydrofolate, which in turn donates methyl group to homocysteine to generate methionine. There exist two\\u000a common low function polymorphic variants of the methylenetetrahydrofolate

Sunil Chandy; M. N. Sadananda Adiga; Girija Ramaswamy; C. Ramachandra; Lakshmi Krishnamoorthy

2008-01-01

345

Effects of nutrition on zinc, folic acid, and vitamin B 12 levels during pregnancy  

Microsoft Academic Search

In this article, we report the results of a case control study carried out on 290 Turkish pregnant women at 5–24 wk of gestation\\u000a to determine their zinc, folic acid, and vitamin B12 levels in relation to their nutritional and socioconomic status. The women were divided into two groups (n=145 each), depending on the stage of gestation. Group I consisted

Maturat Erdogan; Isik Üstüner; Bora Cengiz; Feride Söylemez; Ayhan O. Çavdar

2006-01-01

346

Thyroid hormones and metabolic rate during induction of Vitamin B12 deficiency in goats.  

PubMed

Vitamin B12 deficiency was induced in 15 small East African goats by feeding cobalt deficient Chloris gayana hay (containing 0.02 mg of Co/kg dry matter) over a 25 week experimental period. Cobalt was supplemented as an oral drench to supply 0.3 g of Co/goat/week to 15 treated goats. At intervals of 3-4 weeks, serum concentrations of Vitamin B12 , total thyroxine (TT4), free tetra-iodothyronine (FT4) and free tri-iodothyronine (FT3) were determined by radioimmunoassay, while the rate of resting metabolism was determined by measuring the goats' rate of oxygen consumption. Serum Vitamin B12 concentration was significantly higher (p<0.01) in cobalt-treated (289.6 +/- 40.76 pg/ml) than in control (142.8 +/- 28.27 pg/ml) goats. The mean serum TT4 concentration was significantly (p<0.01) higher in control (59.0 +/- 1.70 nmol/l) than in cobalt-treated (51.6 +/- 2.45 nmol/l) goats. However, the levels of FT4, FT3 and the rate of resting metabolism were unaffected by the goats' cobalt status. Furthermore, the goats did not lose weight or become anaemic. PMID:16031778

Mburu, J N; Kamau, J M; Badamana, M S

1994-10-01

347

Review of interventions for the prevention and control of folate and vitamin B12 deficiencies.  

PubMed

Folate and vitamin B12 deficiencies represent important and evolving global health challenges that contribute to the global burden of anemia, neurologic conditions, neurodevelopmental disorders, and birth defects. We present a review of population-based programs designed to increase consumption of folates and vitamin B12. A folic acid supplementation program targeting couples prior to marriage in China has led to optimal consumption of supplements containing folic acid and a significant reduction of neural tube defects (NTD). Supplementation programs that use mass community education show some promise, but have not been shown to be as effective as targeted education. The success of supplementation programs hinges on a strong and persistent educational component and access to the supplements. Fortification with folic acid has been shown to reduce the prevalence of NTD in the countries where it has been implemented. Challenges to fortification programs include identifying the appropriate delivery vehicles, setting the optimal fortification level, sustaining the quality assurance of the fortification level, and addressing regulatory challenges and trade barriers of commercially fortified flours. Supplementation and fortification are cost-effective and viable approaches to reducing the burden of NTD, anemia, and other conditions resulting from folate deficiency. The experience with interventions involving folic acid could provide a model for the subsequent development of supplementation and fortification programs involving vitamin B12. PMID:18709892

Cordero, José F; Do, Ann; Berry, R J

2008-06-01

348

Folate (vitamin B9) and vitamin B12 and their function in the maintenance of nuclear and mitochondrial genome integrity.  

PubMed

Folate plays a critical role in the prevention of uracil incorporation into DNA and hypomethylation of DNA. This activity is compromised when vitamin B12 concentration is low because methionine synthase activity is reduced, lowering the concentration of S-adenosyl methionine (SAM) which in turn may diminish DNA methylation and cause folate to become unavailable for the conversion of dUMP to dTMP. The most plausible explanation for the chromosome-breaking effect of low folate is excessive uracil misincorporation into DNA, a mutagenic lesion that leads to strand breaks in DNA during repair. Both in vitro and in vivo studies with human cells clearly show that folate deficiency causes expression of chromosomal fragile sites, chromosome breaks, excessive uracil in DNA, micronucleus formation, DNA hypomethylation and mitochondrial DNA deletions. In vivo studies show that folate and/or vitamin B12 deficiency and elevated plasma homocysteine (a metabolic indicator of folate deficiency) are significantly correlated with increased micronucleus formation and reduced telomere length respectively. In vitro experiments indicate that genomic instability in human cells is minimised when folic acid concentration in culture medium is greater than 100nmol/L. Intervention studies in humans show (a) that DNA hypomethylation, chromosome breaks, uracil incorporation and micronucleus formation are minimised when red cell folate concentration is greater than 700nmol/L and (b) micronucleus formation is minimised when plasma concentration of vitamin B12 is greater than 300pmol/L and plasma homocysteine is less than 7.5?mol/L. These concentrations are achievable at intake levels at or above current recommended dietary intakes of folate (i.e. >400?g/day) and vitamin B12 (i.e. >2?g/day) depending on an individual's capacity to absorb and metabolise these vitamins which may vary due to genetic and epigenetic differences. PMID:22093367

Fenech, Michael

2011-11-07

349

Indicators for assessing folate and vitamin B-12 status and for monitoring the efficacy of intervention strategies123  

PubMed Central

Deficiencies of folate or of vitamin B-12 are widespread and constitute a major global burden of morbidity that affect all age groups. Detecting or confirming the presence of folate or vitamin B-12 deficiency and distinguishing one from the other depends, ultimately, on laboratory testing. Tests to determine the presence of folate or vitamin B-12 deficiency are used singly or in combination to establish the nutritional status and prevalence of deficiencies of the vitamins in various populations. The efficacy of interventions through the use of fortification or supplements is monitored by using the same laboratory tests. Tests currently in use have limitations that can be either technical or have a biological basis. Consequently, each single test cannot attain perfect sensitivity, specificity, or predictive value. Laboratory indicators of vitamin B-12 or folate status involve the measurement of either the total or a physiologically relevant fraction of the vitamin in a compartment such as blood. Thus, assays to measure vitamin B-12 or folate in plasma or serum as well as folate in red blood cells are in widespread use, and more recently, methods to measure vitamin B-12 associated with the plasma binding protein transcobalamin (holotranscobalamin) have been developed. Alternatively, concentrations of surrogate biochemical markers that reflect the metabolic function of the vitamin can be used. Surrogates most commonly used are plasma homocysteine, for detection of either vitamin B-12 or folate deficiency, and methylmalonic acid for detection of vitamin B-12 deficiency. The general methods as well as their uses, indications, and limitations are presented.

Green, Ralph

2011-01-01

350

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

PubMed Central

Cobalamin in the form of adenosylcobalamin (Ado-CBL) is known to repress expression of genes for vitamin B12 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 B12-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 B12 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 B12 regulon.

VITRESCHAK, ALEXEY G.; RODIONOV, DMITRY A.; MIRONOV, ANDREY A.; GELFAND, MIKHAIL S.

2003-01-01

351

Dipstick based immunochemiluminescence biosensor for the analysis of vitamin B12 in energy drinks: a novel approach.  

PubMed

In this article, we describe a dipstick based immunochemiluminescence (immuno-CL) biosensor for the detection of vitamin B(12) in energy drinks. The method is a direct competitive type format involving the immobilization of vitamin B(12) antibody on nitrocellulose membrane (NC) followed by treatment with vitamin B(12) and vitamin B(12)-alkaline phosphatase conjugate to facilitate the competitive binding. The dipstick was further treated with substrate disodium 2-chloro-5-(4-methoxyspiro {1,2-dioxetane-3,2¢-(5¢-chloro)tricyclo[3.3.1.13,7]decan}-4-yl)-1-phenyl phosphate (CDP-Star) to generate chemiluminescence (CL). The number of photons generated was inversely proportional to the vitamin B(12) concentration. After systematic optimization, the limit of detection was 1 ng mL(-1). The coefficient of variation was below 0.2% for both intra- and inter-assay precision. Vitamin B(12) was extracted from energy drinks with recovery ranged from 90 to 99.4%. Two different energy drinks samples were analyzed, and a good correlation was observed when the data were compared with a reference enzyme linked immuno sorbent assay (ELISA) method. The developed method is suitable for an accurate, sensitive, and high-throughput screening of vitamin B(12) in energy drinks samples. The dipstick technique based on immuno-CL is suitable for the detection of several analyte in food and environmental samples. PMID:22444541

Selvakumar, L S; Thakur, M S

2012-02-13

352

Vitamin B12 status of pregnant Indian women and cognitive function in their 9-year-old children  

PubMed Central

Background Recent research has highlighted the influence of maternal factors on the health of the offspring. Intrauterine experiences may program metabolic, cardiovascular, and psychiatric disorders. We have shown that maternal vitamin B12 status affects adiposity and insulin resistance in the child. Vitamin B12 is important for brain development and function. Objective We investigated the relationship between maternal plasma vitamin B12 status during pregnancy and the child's cognitive function at 9 years of age. Methods We studied children born in the Pune Maternal Nutrition Study. Two groups of children were selected on the basis of maternal plasma vitamin B12 concentration at 28 weeks of gestation: group 1 (n = 49) included children of mothers with low plasma vitamin B12 (lowest decile, < 77 pM) and group 2 (n = 59) children of mothers with high plasma vitamin B12 (highest decile, > 224 pM). Results Children from group 1 performed more slowly than those from group 2 on the Color Trail A test (sustained attention, 182 vs. 159 seconds; p < .05) and the Digit Span Backward test (short-term memory, p <.05), after appropriate adjustment for confounders. There were no differences between group 1 and group 2 on other tests of cognitive function (intelligence, visual agnosia). Conclusions Maternal vitamin B12 status in pregnancy influences cognitive function in offspring.

Bhate, Vidya; Deshpande, Swapna; Bhat, Dattatray; Joshi, Niranjan; Ladkat, Rasika; Watve, Sujala; Fall, Caroline; de Jager, Celeste A.; Refsum, Helga; Yajnik, Chittaranjan

2009-01-01

353

Recreational nitrous oxide abuse-induced vitamin B12 deficiency in a patient presenting with hyperpigmentation of the skin.  

PubMed

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

2013-06-29

354

Modulator effects of the methylenetetrahydrofolate reductase C677T polymorphism on response to vitamin B12 therapy and homocysteine metabolism.  

PubMed

In this study, our aim was to investigate the association of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism on the vitamin B12 therapy response in 95 patients with vitamin B12 deficiency and 92 healthy control subjects using vitamin B12, plasma total homocysteine (tHcy), and folate as the main measure of outcome. MTHFR C677T genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism techniques. There were no differences in the distribution of MTHFR genotypes in the cases versus the controls. Mean concentrations of plasma tHcy and B12 vitamin were 18.84 ?M and 142.47 pg/mL in patients with TT (10.5%) genotypes. Furthermore, mean concentrations of B12 vitamin after cobalamin therapy were 697.62, 656.64, and 488.76 pg/mL in patients with the CC, CT, and TT genotypes, respectively. The MTHFR 677 TT genotype has decreasing effect in B12 vitamin and increasing effect in tHcy. In comparison with the patients having CC and CT genotypes, patients with the TT genotype had a lower response to vitamin B12 therapy. PMID:22084937

Sensoy, Nazli; ?oysal, Yasemin; Kahraman, Ahmet; Do?an, Nurhan; Imirzalio?lu, Necat

2011-11-15

355

In vitamin B12 deficiency, higher serum folate is associated with increased total homocysteine and methylmalonic acid concentrations  

PubMed Central

In a recent study of older participants (age ?60 years) in the 1999–2002 National Health and Nutrition Examination Survey (NHANES), we showed that a combination of high serum folate and low vitamin B12 status was associated with higher prevalence of cognitive impairment and anemia than other combinations of vitamin B12 and folate status. In the present study, we sought to determine the joint influence of serum folate and vitamin B12 concentrations on two functional indicators of vitamin B12 status, total homocysteine (tHcy) and methylmalonic acid (MMA), among adult participants in phase 2 of the NHANES III (1991–1994) and the NHANES 1999–2002. Exclusion of subjects who were <20 years old, were pregnant, had evidence of kidney or liver dysfunction, or reported a history of alcohol abuse or recent anemia therapy left 4,940 NHANES III participants and 5,473 NHANES 1999–2002 participants for the study. Multivariate analyses controlled for demographic factors, smoking, alcohol use, body mass index, self-reported diabetes diagnosis, and serum concentrations of creatinine and alanine aminotransferase revealed significant interactions between serum folate and serum vitamin B12 in relation to circulating concentrations of both metabolites. In subjects with serum vitamin B12 >148 pmol/liter (L), concentrations of both metabolites decreased significantly as serum folate increased. In subjects with lower serum vitamin B12, however, metabolite concentrations increased as serum folate increased starting at ?20 nmol/L. These results suggest a worsening of vitamin B12's enzymatic functions as folate status increases in people who are vitamin B12-deficient.

Selhub, Jacob; Morris, Martha Savaria; Jacques, Paul F.

2007-01-01

356

Adverse effect of metformin therapy on serum vitamin B12 and folate: short-term treatment causes disadvantages?  

PubMed

Diabetes is a global public health challenge that imposes heavy burdens on communities and individuals. Metformin, the first-line medication for diabetes, has the superiority of reducing risk of macrovascular diseases, all-cause mortality and even possibly cancers. Recent observational studies, however, have demonstrated that long-term metformin therapy increases the probability of vitamin B12 and folate deficiency, and might contribute to the progression of diabetic peripheral neuropathy. Despite metformin is widely used and extensively studied, randomized controlled trials performed to explore the effects of metformin on vitamin B12 and folate are limited. Besides, whether short-term treatment causes vitamin deficiency is a pending issue. We postulate that even a few-month treatment with metformin results in the decrease of vitamin B12 and folate. However, supplementation of vitamin B12 rather than the combination of vitamin B12 and folate might be profitable based on the mechanism of metformin on vitamins in patients with type 2 diabetes. This viewpoint differs from those of majority that a combined supplementation of vitamin B12 and folate is inclined to be advised. PMID:23751310

Xu, Lijuan; Huang, Zhimin; He, Xiaoying; Wan, Xuesi; Fang, Donghong; Li, Yanbing

2013-06-14

357

Effects of ?-irradiation and cooking on vitamins B6 and B12 in grass prawns (Penaeus monodon)  

NASA Astrophysics Data System (ADS)

The effects of irradiation doses, irradiation temperature and a combined treatment of irradiation and cooking on the vitamin B6 and B12 contents of grass prawns have been studied. Grass prawns were irradiated at refrigerated (4°C) or frozen (-20°C) temperatures with different doses. A domestic cooking procedure was followed after irradiation. The changes in vitamins B6 and B12 of both raw and cooked grass prawns were evaluated. Results showed no significant changes of vitamin B6 and B12 in grass prawns with a radiation dose up to 7 kGy at either 4°C or -20°C. Irradiation at 4°C caused more destruction of vitamin B12 but not vitamin B6 than did irradiation at -20°C in grass prawns. There was significant destruction of both vitamins B6 and B12 in unirradiated samples during cooking. The introduction of the irradiation process before cooking had no effect on either vitamin. These results indicate that the loss of vitamins B6 and B12 in the combined treatments was caused mainly by thermal destruction.

Hau, L.-B.; Liew, M.-S.

1993-07-01

358

Common variant in FUT2 gene is associated with levels of vitamin B(12) in Indian population.  

PubMed

Vitamin B(12) is an essential micronutrient synthesized by microorganisms. Mammals including humans have evolved ways for transport and absorption of this vitamin. Deficiency of vitamin B(12) (either due to low intake or polymorphism in genes involved in absorption and intracellular transport of this vitamin) has been associated with various complex diseases. Genome-wide association studies have recently identified several common single nucleotide polymorphisms (SNPs) in fucosyl transferase 2 gene (FUT2) to be associated with levels of vitamin B(12)-the strongest association was with a non-synonymous SNP rs602662 in this gene. In the present study, we attempted to replicate the association of this SNP (rs602662) in an Indian population since a significant proportion has been reported to have low levels of vitamin B(12) in this population. A total of 1146 individuals were genotyped for this SNP using a single base extension method and association with levels of vitamin B(12) was assessed in these individuals. Regression analysis was performed to analyze the association considering various confounding factors like for age, sex, diet, hypertension, diabetes mellitus and coronary artery disease status. We found that the SNP rs602662 was significantly associated with the levels of vitamin B(12) (p value<0.0001). We also found that individuals adhering to a vegetarian diet with GG (homozygous major genotype) have significantly lower levels of vitamin B(12) in these individuals. Thus, our study reveals that vegetarian diet along with polymorphism in the FUT2 gene may contribute significantly to the high prevalence of vitamin B(12) deficiency in India. PMID:23201895

Tanwar, Vinay Singh; Chand, Mandeep P; Kumar, Jitender; Garg, Gaurav; Seth, Sandeep; Karthikeyan, Ganesan; Sengupta, Shantanu

2012-11-29

359

Multiple micronutrient supplementation improves vitamin B 12 and folate concentrations of HIV infected children in Uganda: a randomized controlled trial  

Microsoft Academic Search

Background  The effect of multiple micronutrient supplementation on vitamin B12 and folate has hither to not been reported in African HIV infected children. This paper describes vitamin B12 and folate status of Ugandan HIV infected children aged 1-5 years and reports the effect of multiple micronutrient supplementation\\u000a on serum vitamin B12 and folate concentrations.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Of 847 children who participated in a

Grace Ndeezi; James K Tumwine; Christopher M Ndugwa; Bjørn J Bolann; Thorkild Tylleskär

2011-01-01

360

Levels of circulating homocysteine, vitamin B6, vitamin B12, and folate in different types of open-angle glaucoma  

PubMed Central

Objective: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG). Study design: A prospective controlled trial. Participants and methods: Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin supplements or medications affecting Hcy and vitamin levels were excluded from the study. The levels of Hcy and vit-B6 were measured by High Performance Liquid Chromatography (HPLC). The levels of serum vit-B12 and folic acid were measured by competitive chemiluminescent enzyme immunoassay (CEI). One-way analysis if variance (ANOVA), analysis of covariance (ANCOVA), and the Tukey honestly significant difference test were used for statistical analysis. Results: The mean Hcy level of the PXG group was 15.46 ± 9.27 ?mol/L which was significantly higher (P = 0.03) than that of the control group. There were no statistical differences in serum vit-B12 and folate levels among control subjects and NTG, PXG and POAG groups (P > 0.05). It was found that the mean plasma vit-B6 level was significantly higher in subjects with NTG (P = 0.03) and POAG (P = 0.025) versus controls. Mean vit-B6 levels in NTG and POAG were 30.50 ± 11.29 ?g/L and 30 ± 12.15 ?g/L, respectively. Conclusions: The plasma level of Hcy was found to be increased only in PXG patients and the plasma levels of vit-B6 were found to increase in the NTG and POAG sample groups. Using homocysteine and vit-B6 levels as the determinants of hyperhomocysteinemia still needs further research.

Turgut, Burak; Kaya, Murat; Arslan, Sermal; Demir, Tamer; Guler, Mete; Kaya, Mehmet Kaan

2010-01-01

361

Genetic architecture of vitamin B12 and folate levels uncovered applying deeply sequenced large datasets.  

PubMed

Genome-wide association studies have mainly relied on common HapMap sequence variations. Recently, sequencing approaches have allowed analysis of low frequency and rare variants in conjunction with common variants, thereby improving the search for functional variants and thus the understanding of the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B(12) (B12) and folate. Up to 22.9 million sequence variants were analyzed in combined samples of 45,576 and 37,341 individuals with serum B(12) and folate measurements, respectively. We found six novel loci associating with serum B(12) (CD320, TCN2, ABCD4, MMAA, MMACHC) or folate levels (FOLR3) and confirmed seven loci for these traits (TCN1, FUT6, FUT2, CUBN, CLYBL, MUT, MTHFR). Conditional analyses established that four loci contain additional independent signals. Interestingly, 13 of the 18 identified variants were coding and 11 of the 13 target genes have known functions related to B(12) and folate pathways. Contrary to epidemiological studies we did not find consistent association of the variants with cardiovascular diseases, cancers or Alzheimer's disease although some variants demonstrated pleiotropic effects. Although to some degree impeded by low statistical power for some of these conditions, these data suggest that sequence variants that contribute to the population diversity in serum B(12) or folate levels do not modify the risk of developing these conditions. Yet, the study demonstrates the value of combining whole genome and exome sequencing approaches to ascertain the genetic and molecular architectures underlying quantitative trait associations. PMID:23754956

Grarup, Niels; Sulem, Patrick; Sandholt, Camilla H; Thorleifsson, Gudmar; Ahluwalia, Tarunveer S; Steinthorsdottir, Valgerdur; Bjarnason, Helgi; Gudbjartsson, Daniel F; Magnusson, Olafur T; Sparsø, Thomas; Albrechtsen, Anders; Kong, Augustine; Masson, Gisli; Tian, Geng; Cao, Hongzhi; Nie, Chao; Kristiansen, Karsten; Husemoen, Lise Lotte; Thuesen, Betina; Li, Yingrui; Nielsen, Rasmus; Linneberg, Allan; Olafsson, Isleifur; Eyjolfsson, Gudmundur I; Jørgensen, Torben; Wang, Jun; Hansen, Torben; Thorsteinsdottir, Unnur; Stefánsson, Kari; Pedersen, Oluf

2013-06-06

362

Genetic Architecture of Vitamin B12 and Folate Levels Uncovered Applying Deeply Sequenced Large Datasets  

PubMed Central

Genome-wide association studies have mainly relied on common HapMap sequence variations. Recently, sequencing approaches have allowed analysis of low frequency and rare variants in conjunction with common variants, thereby improving the search for functional variants and thus the understanding of the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B12 (B12) and folate. Up to 22.9 million sequence variants were analyzed in combined samples of 45,576 and 37,341 individuals with serum B12 and folate measurements, respectively. We found six novel loci associating with serum B12 (CD320, TCN2, ABCD4, MMAA, MMACHC) or folate levels (FOLR3) and confirmed seven loci for these traits (TCN1, FUT6, FUT2, CUBN, CLYBL, MUT, MTHFR). Conditional analyses established that four loci contain additional independent signals. Interestingly, 13 of the 18 identified variants were coding and 11 of the 13 target genes have known functions related to B12 and folate pathways. Contrary to epidemiological studies we did not find consistent association of the variants with cardiovascular diseases, cancers or Alzheimer's disease although some variants demonstrated pleiotropic effects. Although to some degree impeded by low statistical power for some of these conditions, these data suggest that sequence variants that contribute to the population diversity in serum B12 or folate levels do not modify the risk of developing these conditions. Yet, the study demonstrates the value of combining whole genome and exome sequencing approaches to ascertain the genetic and molecular architectures underlying quantitative trait associations.

Thorleifsson, Gudmar; Ahluwalia, Tarunveer S.; Steinthorsdottir, Valgerdur; Bjarnason, Helgi; Gudbjartsson, Daniel F.; Magnusson, Olafur T.; Spars?, Thomas; Albrechtsen, Anders; Kong, Augustine; Masson, Gisli; Tian, Geng; Cao, Hongzhi; Nie, Chao; Kristiansen, Karsten; Husemoen, Lise Lotte; Thuesen, Betina; Li, Yingrui; Nielsen, Rasmus; Linneberg, Allan; Olafsson, Isleifur; Eyjolfsson, Gudmundur I.; J?rgensen, Torben; Wang, Jun; Hansen, Torben; Thorsteinsdottir, Unnur; Stefansson, Kari; Pedersen, Oluf

2013-01-01

363

Vitamin B12 Deficiency Is Very Prevalent in Lactating Guatemalan Women and Their Infants at Three Months Postpartum1,2,3  

Microsoft Academic Search

Vitamin B-12 status was evaluated in 113 Guatemalan women and their infants at 3 mo of lactation. Plasma vitamin B-12 was deficient or low in 46.7% of the mothers, and holotranscobalamin II (holo TC II) concentra- tions were low in 32.3%, which may indicate vitamin B-12 malabsorption. Only 9% had deficient or low plasma folate. Breast milk vitamin B-12 was

Jennifer E. Casterline; Lindsay H. Allen; Marie T. Ruel

364

Vitamin B12 and methionine synthesis: a critical review. Is nature's most beautiful cofactor misunderstood?  

PubMed

The mechanism by which Vitamin B12 prevents demyelination of nerve tissue is still not known. The evidence indicates that the critical site of B12 function in nerve tissue is in the enzyme, methionine synthase, in a system which requires S-adenosylmethionine. In recent years it has been recognized that S-adenosylmethionine gives rise to the deoxyadenosyl radical which catalyzes many reactions including the rearrangement of lysine to beta-lysine. Evidence is reviewed which suggests that there is an analogy between the two systems and that S-adenosyl methionine may catalyze a rearrangement of homocysteine on methionine synthase giving rise to iso- or beta-methionine. The rearranged product is readily degraded to CH3-SH, providing a mechanism for removing toxic homocysteine. PMID:16614482

Toohey, John I

2006-01-01

365

Helicobacter pylori associated vitamin B12 deficiency, pernicious anaemia and subacute combined degeneration of the spinal cord.  

PubMed

A 23-year-old man presented with weakness in the lower limbs, numbness in hands and feet over past 6 months. Examination revealed a combination of absent ankle jerk, extensor plantar response and reduced sensations in a glove and stocking distribution. MRI of the spinal cord was distinctive of subacute combined degeneration (SACD) of the spinal cord. Serum vitamin B12 was low and anti-intrinsic factor antibodies were positive. A biopsy of the stomach revealed intense inflammatory infiltrates in lamina propria with grade III Helicobacter pylori infection. Other work-up for the cause of vitamin B12 deficiency was unremarkable. H pylori infection triggers autoantibodies by a mechanism of molecular mimicry. This case report highlights H pylori as a causative agent in vitamin B12 deficiency and culminating in SACD of the spinal cord. H pylori treatment reverses the underlying pathogenesis and corrects vitamin B12 deficient state in selected individuals. PMID:24081591

Gowdappa, H Basavana; Mahesh, M; Murthy, K V K S N; Narahari, M G

2013-09-30

366

Vitamin B12 extensive thoracic myelopathy: clinical, radiological and prognostic aspects. Two cases report and literature review.  

PubMed

The myelopathy caused by vitamin B12 deficiency is known as subacute combined degeneration. It is rare, but a well known cause of demyelination of the dorsal columns of the spinal cord. The magnetic resonance imaging is characterized by an increased signal on T2-weighted images involving the posterior columns of cervical and thoracic cord. There have been few cases in literature with extensive lesions (more than seven levels) of the thoracic spinal cord. The clinical and radiological improvements are possible if the replacement of vitamin B12 is initiated precocious. We present two rare cases of extensive thoracic myelopathy due to vitamin B12 deficiency. The first is a young woman with complete clinical recovery and important radiologic improvement after early treatment. In addition, the second case is an older man with partial response to the treatment. Those cases illustrate the importance of considering vitamin B12 deficiency in any patient, who presents with myelopathy. PMID:23468407

de Medeiros, Frederico Carvalho; de Albuquerque, Lucas Alverne Freitas; de Souza, Renata Brant; Gomes Neto, Antonio Pereira; Christo, Paulo Pereira

2013-03-07

367

LOW PLASMA VITAMIN B12 AND HIGH FOLATE CONCENTRATIONS IN PREGNANCY ARE ASSOCIATED WITH GESTATIONAL DIABESITY AND INCIDENT DIABETES  

PubMed Central

Aim To test the hypothesis that low plasma vitamin B12 concentrations combined with high folate concentrations in pregnancy are associated with higher incidence of gestational diabetes (GDM) and later diabetes. Methods Women (N=785) attending the antenatal clinics of the Holdsworth Memorial Hospital, Mysore, India had their anthropometry, insulin resistance (Homeostasis Model Assessment) and glucose tolerance assessed at 30 weeks gestation (100g Oral Glucose Tolerance Test/ OGTT; Carpenter-Coustan criteria), and five years after delivery (75g OGTT, WHO 1999). Vitamin B12 and folate concentrations in pregnancy were measured in stored frozen plasma samples. Results Low vitamin B12 concentrations (<150 pmol/l, B12 deficiency) were observed in 43% of women and low folate concentrations (<7 nmol/l) in 4%. Women with vitamin B12 deficiency had higher body mass index (BMI; P<0.001), sum of skinfolds (P<0.001), insulin resistance (P=0.02) and a higher incidence of GDM (8.7% v 4.6%; OR=2.14, P=0.02; P=0.1 after adjusting for maternal BMI) than non-deficient women. Among vitamin B12-deficient women the incidence of GDM increased with folate concentration (5.6%, 8.8%, 12.8% respectively from lowest to highest third; P for interaction=0.2). B12 deficiency during pregnancy predicted larger skinfolds, increased insulin resistance (P<0.05) and incident diabetes at 5-year follow-up (P=0.02, after adjusting for current BMI). Conclusion Maternal vitamin B12 deficiency is associated with increased adiposity and, in turn, with increased insulin resistance and GDM, especially in the presence of high folate concentrations. Vitamin B12 deficiency may be an important factor underlying the high risk of diabesity in south Asian Indians.

Krishnaveni, GV; Hill, JC; Veena, SR; Bhat, DS; Wills, AK; Chachyamma, KJ; Karat, SC; Yajnik, CS; Fall, CHD

2012-01-01

368

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

2013-01-09

369

Decreased intrinsic factor secretion in AIDS: relation to parietal cell acid secretory capacity and vitamin B12 malabsorption.  

PubMed

AIDS-associated gastric secretory failure has been characterized by decreased secretion of acid, pepsin, and gastric juice volume. To determine whether decreased intrinsic factor secretion and vitamin B12 malabsorption occur in this entity, we performed prospective measurements of maximal acid output, intrinsic factor output, vitamin B12 absorption, serum vitamin B12, and holotranscobalamin II in 10 consecutive AIDS patients. Four of 10 patients had low maximal acid output, i.e., < or = 1.5 mEq/h (control = 12.8 +/- 9.0, range 2.5-25 mEq/h). Four patients had low intrinsic factor output, i.e., < or = 1.1 microgram/h (control = 8.2 +/- 6.9, range 3.1-19.4 micrograms/h). One patient with low intrinsic factor output had low serum vitamin B12 and a Schilling test consistent with pernicious anemia. A second patient with very low intrinsic factor output (0.16 micrograms/h) had low parts I and II Schilling tests; malabsorption most likely resulted from both low intrinsic factor secretion and ileal disease. One of three vitamin B12 malabsorbing patients, with normal serum vitamin B12, had low holotranscobalamin II, 25 pg/ml (control holotranscobalamin II = 76 +/- 44, range 44-152 pg/ml). Maximal acid output and intrinsic factor output did not correlate in AIDS (r = 0.36, p = 0.30) in contrast to the expected correlation in controls (r = 0.91, p = 0.03). We conclude that low intrinsic factor secretion is common in AIDS and contributes to vitamin B12 malabsorption. Decreased parietal cell secretion of intrinsic factor and acid may occur independently in human immunodeficiency virus-associated gastric secretory failure. Low holotranscobalamin II, an early manifestation of vitamin B12 malabsorption, results in decreased delivery to vitamin B12-dependent tissues prior to depletion of serum vitamin B12. Regular supplementation with vitamin B12 may therefore be warranted in patients with advanced HIV infection. PMID:1449141

Herzlich, B C; Schiano, T D; Moussa, Z; Zimbalist, E; Panagopoulos, G; Ast, A; Nawabi, I

1992-12-01

370

Release of toxic Gd3+ ions to tumour cells by vitamin B12 bioconjugates.  

PubMed

Two probes consisting of vitamin B(12) (CNCbl) conjugated to Gd chelates by esterification of the ribose 5'-OH moiety, Gd-DTPA-CNCbl (1; DTPA = diethylenetriamine-N,N,N',N'',N''-pentaacetic acid) and Gd-TTHA-CNCbl (2; TTHA = triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid), have been synthesised and characterised. The crystal structure of a dimeric form of 1, obtained by crystallisation with an excess of GdCl(3), has been determined. The kinetics of binding to and dissociation from transcobalamin II show that 1 and 2 maintain high-affinity binding to the vitamin B(12) transport protein. Complex 2 is very stable with respect to Gd(3+) release owing to the saturated co-ordination of the Gd(3+) ion by four amino and five carboxylate groups. Hydrolysis of the ester functionality occurs on the time scale of several hours. The lack of saturation and the possible involvement of the ester functionality in co-ordination result in lower stability of 1 towards hydrolysis and in a considerable release of Gd(3+) in vitro. Gd(3+) ions released from 1 are avidly taken up by the K562 tumour cells to an extent corresponding to approximately 10(10) Gd(3+) per cell. The internalisation of toxic Gd(3+) ions causes a marked decrease in cell viability as assessed by Trypan blue and WST-1 tests. On the contrary, the experiments with the more stable 2 did not show any significant cell internalisation of Gd(3+) ions and any influence on cell viability. The results point to new avenues of in situ generation of cytotoxic pathways based on the release of toxic Gd(3+) ions by vitamin B(12) bioconjugates. PMID:19562781

Siega, Patrizia; Wuerges, Jochen; Arena, Francesca; Gianolio, Eliana; Fedosov, Sergey N; Dreos, Renata; Geremia, Silvano; Aime, Silvio; Randaccio, Lucio

2009-08-10

371

An evaluation of plasma homocysteine in the assessment of vitamin B12 status of pasture-fed sheep  

Microsoft Academic Search

AIM: To assess the diagnostic potential of concentrations of homocysteine (Hcy) in plasma in relation to those of methylmalonic acid (MMA) and vitamin B12, as predictors of responsiveness of young sheep to supplementation with vitamin B12.METHODS: Eighty-two ewes grazing ryegrass-white clover pasture were used, 39 of which had been supplemented with a Co bullet and 43 unsupplemented. Thirty days after

JM Furlong; JR Sedcole; AR Sykes

2010-01-01

372

Vitamin B12 Is a Strong Determinant of Low Methionine Synthase Activity and DNA Hypomethylation in Gastrectomized Rats  

Microsoft Academic Search

Background\\/Aims: The respective influence of folate and vitamin B12 deficiency on MTR activity and transcription, and on DNA methylation is not clearly established. The aim of this study was to assess the respective influence of folate and vitamin B12 deficiency on MTR transcription and activity, and on DNA methylation. Methods: Sixty-one rats were administered normal diet or diet deficient in

Laurent Brunaud; Jean-Marc Alberto; Ahmet Ayav; Philippe Gérard; Farès Namour; Laurent Antunes; Marc Braun; Jean-Pierre Bronowicki; Laurent Bresler; Jean-Louis Guéant

2003-01-01

373

Helicobacter pylori infection does not influence the efficacy of iron and vitamin B12 fortification in marginally nourished Indian children  

Microsoft Academic Search

Background\\/Objectives:Helicobacter pylori infection and iron and vitamin B12 deficiencies are widespread in economically disadvantaged populations. There is emerging evidence that H. pylori infection has a negative effect on the absorption of these micronutrients. The aim of this study was to evaluate the effect of H. pylori infection on the efficacy of micronutrient (including iron and vitamin B12)-fortified foods supplied for

P Thankachan; S Muthayya; A Sierksma; A Eilander; T Thomas; G S Duchateau; L G J Frenken; A V Kurpad

2010-01-01

374

Vitamin B12 Treatment Normalizes Metabolic Markers But Has Limited Clinical Effect: A Randomized Placebo-controlled Study  

Microsoft Academic Search

Background: The clinical significance of increased plasma methylmalonic acid (P-MMA) is unclear. We assessed the efficacy of vitamin B12 treatment in reduc- ing P-MMA and plasma total homocysteine compared with the clinical benefits of treatment. Methods: We studied 140 individuals with mildly to modestly increased P-MMA (0.40 -2.00 mmol\\/L), not pre- viously treated with vitamin B12, in a randomized, placebo-controlled

Anne-Mette Hvas; Jørgen Ellegaard; Ebba Nexø

2001-01-01

375

High prevalence of folic acid and vitamin B12 deficiencies in infants, children, adolescents and pregnant women in Venezuela  

Microsoft Academic Search

Background:There is increased worldwide concern about the consequences of folic acid and vitamin B12 deficiencies on health, which include megaloblastic anemia, neural tube defects and cardiovascular disease.Objective:This study intended to determine the prevalence of folic acid and vitamin B12 deficiencies in vulnerable groups in labor and poor socioeconomic strata of the Venezuelan population.Methods:A total of 5658 serum samples were processed

M N García-Casal; C Osorio; M Landaeta; I Leets; P Matus; F Fazzino; E Marcos

2005-01-01

376

Anaemia in rheumatoid arthritis: the role of iron, vitamin B12, and folic acid deficiency, and erythropoietin responsiveness  

Microsoft Academic Search

Thirty six patients with rheumatoid arthritis (RA) (25 with anaemia) were studied to establish the role of iron, vitamin B12, and folic acid deficiency, erythropoietin responsiveness, and iron absorption in the diagnosis and pathogenesis of anaemia in RA. Iron deficiency, assessed by stainable bone marrow iron content, occurred in 13\\/25 (52%), vitamin B12 deficiency in 7\\/24 (29%), and folic acid

G Vreugdenhil; A W Wognum; H G van Eijk; A J Swaak

1990-01-01

377

Determination of vitamin B 12 in multivitamin tablets and fermentation medium by high-performance liquid chromatography with fluorescence detection  

Microsoft Academic Search

A novel method for the determination of vitamin B12 by high-performance liquid chromatography with fluorescence detection is reported. The method was simple and highly sensitive with good precision. Vitamin B12 was analyzed by HPLC on a ?Bondapak C18 column (300×3.9 mm, 10 ?m) with methanol–water (30:70) as mobile phase and fluorescence detection at 305 nm (with excitation at 275 nm).

Hua-Bin Li; Feng Chen; Yue Jiang

2000-01-01

378

High serum vitamin B12 binding capacity as a marker of the fibrolamellar variant of hepatocellular carcinoma  

Microsoft Academic Search

Ten (9.3%) of 107 patients with hepatocellular carcinoma had considerably increased serum unsaturated vitamin B12 binding capacity. All 10 were young (mean 12 years), had no serum alpha-fetoprotein, and no underlying cirrhosis; all had a longer survival compared with patients without increased serum unsaturated vitamin B12 binding capacity in the study. Seven of the 10 patients had fibrolamellar hepatocellular carcinoma,

F J Paradinas; W M Melia; M L Wilkinson; B Portmann; P J Johnson; I M Murray-Lyon; R Williams

1982-01-01

379

High rate of maternal vitamin B12 deficiency nearly a decade after Canadian folic acid flour fortification  

Microsoft Academic Search

Summary Vitamin B12 deficiency may be an independent risk factor for neural tube defects (NTD). We determined the prevalence of biochemical B12 deficiency (<125 pmol\\/l) among 10 622 Ontarian women aged 15-46 years who underwent con- comitant testing of serum bhCG and B12 9 years after the implementation of Canadian folic acid flour fortification. The overall prevalence of bio- chemical

J. G. Ray; J. Goodman; P. R. A. O'Mahoney; M. M. Mamdani; D. Jiang

2008-01-01

380

Dual isotope Schilling test for measuring absorption of food-bound and free vitamin B12 simultaneously  

SciTech Connect

A prototype food-bound vitamin B12 (food-B12) absorption test has been developed in which /sup 57/Co-B12 was incorporated in vitro into egg yolk (yolk-B12) and served to volunteers in 50-g cooked portions together with toast and coffee for breakfast. Six hours later, 1 mg nonlabeled B12 was given intramuscularly and 24-hour urine was collected for radioactivity measurement. In separate tests, the absorption of yolk-B12 and crystalline /sup 57/Co-B12 was equally poor in patients with pernicious anemia. However, in patients with simple gastric achlorhydria and those who had undergone gastric surgery, the assimilation of yolk-B12 was impaired greatly, whereas the absorption of crystalline radio-B12 was normal. Egg yolk labeled with /sup 58/Co-B12 was administered together with crystalline /sup 57/Co-B12 in a dual isotope test with results similar to those obtained when the tests were prepared separately. This yolk-/sup 58/Co-B12 test with its ability to detect malabsorption of food-B12 may be considered as an addition to the first part of the Schilling test.

Doscherholmen, A.; Silvis, S.; McMahon, J.

1983-10-01

381

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

2013-08-30

382

An investigation of vitamin B12 deficiency in elderly inpatients in neurology department  

Microsoft Academic Search

Objective  To investigate the status of vitamin B12 deficiency in elderly inpatients in the department of neurology.\\u000a \\u000a \\u000a \\u000a Methods  A total number of 827 patients in the department of neurology of Shanghai Punan hospital, from March 2007 to July 2008, were\\u000a employed in the present study. They were 60 years or older, and the average age was 77.1±7.5 years old. All the patients

Yu-Hui Wang; Fang Yan; Wen-Bo Zhang; Gang Ye; Yun-Yun Zheng; Xu-Hua Zhang; Fu-Yuan Shao

2009-01-01

383

Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization  

PubMed Central

Background Nickel (Ni) and cobalt (Co) are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited. Results We carried out comparative genomic analyses to examine occurrence and evolutionary dynamics of the use of Ni and Co at the level of (i) transport systems, and (ii) metalloproteomes. Our data show that both metals are widely used in bacteria and archaea. Cbi/NikMNQO is the most common prokaryotic Ni/Co transporter, while Ni-dependent urease and Ni-Fe hydrogenase, and B12-dependent methionine synthase (MetH), ribonucleotide reductase and methylmalonyl-CoA mutase are the most widespread metalloproteins for Ni and Co, respectively. Occurrence of other metalloenzymes showed a mosaic distribution and a new B12-dependent protein family was predicted. Deltaproteobacteria and Methanosarcina generally have larger Ni- and Co-dependent proteomes. On the other hand, utilization of these two metals is limited in eukaryotes, and very few of these organisms utilize both of them. The Ni-utilizing eukaryotes are mostly fungi (except saccharomycotina) and plants, whereas most B12-utilizing organisms are animals. The NiCoT transporter family is the most widespread eukaryotic Ni transporter, and eukaryotic urease and MetH are the most common Ni- and B12-dependent enzymes, respectively. Finally, investigation of environmental and other conditions and identity of organisms that show dependence on Ni or Co revealed that host-associated organisms (particularly obligate intracellular parasites and endosymbionts) have a tendency for loss of Ni/Co utilization. Conclusion Our data provide information on the evolutionary dynamics of Ni and Co utilization and highlight widespread use of these metals in the three domains of life, yet only a limited number of user proteins.

Zhang, Yan; Rodionov, Dmitry A; Gelfand, Mikhail S; Gladyshev, Vadim N

2009-01-01

384

Investigation of hemorheological parameters at the diagnosis and the follow-up of nutritional vitamin b12 deficient children.  

PubMed

We aimed to investigate the effects of vitamin B12 deficiency on hemorheological parameters, and the changes in these parameters following vitamin B12 treatment. 33 patients (mean-age:7 ± 5.7 years) diagnosed as nutritional vitamin B12 deficiency, and 31 age and sex matched controls (mean-age:7.1 ± 5.2 years) were enrolled. Erythrocyte deformability and aggregation were determined by an ectacytometer, plasma and whole blood viscosities by a cone-plate rotational viscometer. The differences between patients and controls were compared. Hemorheological parameters were repeated in the patient group following vitamin B12 treatment, and the results were compared with the initial results. In vitamin B12 deficiency, erythrocyte deformability and whole blood viscosity were found to be significantly decreased, eythrocyte aggregation was found to be significantly increased compared with the controls. Plasma viscosity was found to be decreased in deficiency but this decrease was not statistically significant. In patient group, erythrocyte deformability, whole blood and plasma viscosities were found to be significantly increased and erythrocyte aggregation was significantly decreased, after treatment. This study indicates that vitamin B12 deficiency has important effects on hemorheological parameters and adequate treatment of deficiency not only corrects the hematological parameters, but also by helping to normalize the hemorheological parameters, may contribute to the regulation of microvascular perfusion. PMID:23719423

Tancer-Elci, Hazal; Isik-Balc?, Yasemin; Bor-Kucukatay, Melek; Kilic-Toprak, Emine; Kilic-Erkek, Ozgen; Senol, Hande; Aybek, Hülya

2013-05-29

385

Vitamin B12 deficiency in African American and white octogenarians and centenarians in Georgia  

Microsoft Academic Search

Objective  Test the hypotheses that vitamin B12 deficiency would be prevalent in octogenarians and centenarians and associated with age,\\u000a gender, race\\/ethnicity, living arrangements (community or skilled nursing facility), animal food intake, B-vitamin supplement\\u000a use, atrophic gastritis, folate status, and hematological indicators.\\u000a \\u000a \\u000a \\u000a Design  Population-based multi-ethnic sample of adults aged 80 to 89 and 98 and above.\\u000a \\u000a \\u000a \\u000a Setting  Northern Georgia in the United States.\\u000a \\u000a \\u000a \\u000a Participants  Men

Mary Ann Johnson; D. B. Hausman; A. Davey; L. W. Poon; R. H. Allen; S. P. Stabler

386

Vitamin B12 deficiency in African American and white octogenarians and centenarians in Georgia  

Microsoft Academic Search

Objective  Test the hypotheses that vitamin B12 deficiency would be prevalent in octogenarians and centenarians and associated with age,\\u000a gender, race\\/ethnicity, living arrangements (community or skilled nursing facility), animal food intake, B-vitamin supplement\\u000a use, atrophic gastritis, folate status, and hematological indicators.\\u000a \\u000a \\u000a \\u000a \\u000a Design  Population-based multi-ethnic sample of adults aged 80 to 89 and 98 and above.\\u000a \\u000a \\u000a \\u000a Setting  Northern Georgia in the United States.\\u000a \\u000a \\u000a \\u000a Participants  Men

Mary Ann Johnson; D. B. Hausman; A. Davey; L. W. Poon; R. H. Allen; S. P. Stabler

2010-01-01

387

Low holotranscobalamin II is the earliest serum marker for subnormal vitamin B12 (cobalamin) absorption in patients with AIDS.  

PubMed

In AIDS, as previously found in pernicious anemia (PA), the earliest serum marker of subnormal vitamin B12 (cobalamin) absorption, and therefore of negative B12 balance, is low serum holotranscobalamin II (holo-TC II; B12-TC II) despite normal total serum B12 level, normal serum homocysteine, and normal classic (oral free radio-B12) Schilling test. This may be accompanied by subtle and insidious damage to hematopoietic, immunologic, neuropsychiatric, nutritional and alimentary systems, confirmed by correction on therapeutic trial with B12 therapy. Our studies suggest such selective B12 deficiency occurs in about half of the HIV-1 infected, in part due to frequent depression of B12 absorption by HIV-1 attack on the gastric mucosa and/or opportunistic infection attack on the small bowel, and in part due to a telescoping of the continuum of the stages of negative B12 balance in relation to damage to B12 delivery by the infective and/or systemic disease process. In AIDS, when total serum B12 is normal despite tissue depletion of B12, if the classic Schilling test does not reveal subnormal food B12 absorption, the food Schilling test does. We hypothesize that DNA-synthesizing cells of the hematopoietic, immunologic, neurologic and other systems which have surface receptors solely for holo-TC II, and which have low B12 stores, rapidly become dysfunctional due to B12 deficiency when holo-TC II is low, while cells (such as liver cells) which also have surface receptors for holohaptocorrin (B12-haptocorrin) remain B12-replete. We believe this to be another example of the concept of selective nutrient deficiency in one cell line but not another. PMID:2339679

Herbert, V; Fong, W; Gulle, V; Stopler, T

1990-06-01

388

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

PubMed

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

Tufan, Ali Evren; Bilici, Rabia; Usta, Genco; Erdo?an, Ayten

2012-06-22

389

Effect of isotretinoin treatment on plasma holotranscobalamin, vitamin B12, folic acid, and homocysteine levels: non-controlled study.  

PubMed

Isotretinoin (Iso) has been used for the treatment of acne. Some previous studies reported elevated homocysteine (Hcy) levels after treatment with Iso. Some side effects have clinical presentations similar to vitamin B12, folic acid deficiencies, and hyperhomocysteinemia. In the present study we evaluated the plasma Hcy levels, the vitamins involved in its metabolism (vitamin B12 and folic acid), and holotranscobalamin (HoloTC), a transport system for vitamin B12 absorption in patients receiving Iso treatment for acne vulgaris. A total of 66 patients with acne vulgaris between the ages of 18 and 40 years were included. Screening for hemoglobin, creatinine, SGOT, SGPT, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and very low-density lipoprotein cholesterol (VLDL-C), folic acid, vitamin B12, Hcy, and HoloTC were done just before initiation (pretreatment) and after four months of Iso treatment (posttreatment). Posttreatment vitamin B12, folic acid, and HoloTC levels were significantly lower while Hcy levels were significantly higher compared with initial values. Posttreatment total cholesterol, LDL-C, triglycerides, VLDL-C, SGPT, and SGOT levels were also higher, and HDL-C levels were lower compared with initial values while there was no change in hemoglobin levels during Iso treatment. We found that Iso usage might cause decreased vitamin B12, folic acid, and HoloTC. These Iso side effects might contribute to the missing link between Iso usage, hyperhomocysteinemia, and neuropsychiatric disorders. Trials may be made with the aim of demonstrating (clearly) if starting vitamin B12 and folic acid replacement therapies with Iso treatment initialization could be useful for preventing hyperhomocysteinemia and possibly related disorders. PMID:22098008

Karadag, Ayse Serap; Tutal, Emre; Ertugrul, Derun Taner; Akin, Kadir Okhan

2011-12-01

390

[Vitamin B12 deficiency in children--underestimated danger in the light of new knowledge].  

PubMed

Vitamin B12 (cobalamin) has two active forms, adenosylcobalamin and methylcobalamin which have a key role in two important metabolic pathways in humans and their deficiency is responsible for clinical problems. Cobalamin is essential during whole life, but its sufficient amount is extra important in fetal and neonatal period, when it is essential for normal child growth and development as well as for normal development of the central nervous system. Because of very complex transport and metabolism, its deficiency can be manifested in numerous congenital and acquired disorders. Vitamin B12 deficiency mostly has non-specific clinical features, it carries a great risk of permanent consequences, but most frequently it is easily curable if diagnosed on time. In Croatia cobalamin deficiency in children has been diagnosed too rarely. Accordingly, the aim of this paper is to point to the recently gained knowledge on cobalamin metabolism, present typical case reports and to provide guidelines for rapid and proper diagnostic and therapeutic approach. PMID:21644278

Juras, Karin; Fumi?, Ksenija; Izakovi?, Senka; Puselji?, Silvija; Culi?, Vida; Gali?, Slobodan; Buljevi?, Andrea Dasovi?; Benjak, Vesna; Coli?, Ana; Frkovi?, Sanda Huljev; Maradin, Miljenka; Sarnavka, Vladimir; Bili?, Karmen; Baumgartner, Matthias; Bari?, Ivo

391

Oral versus intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency: a pragmatic, randomised, multicentre, non-inferiority clinical trial undertaken in the primary healthcare setting (Project OB12)  

PubMed Central

Background The oral administration of vitamin B12 offers a potentially simpler and cheaper alternative to parenteral administration, but its effectiveness has not been definitively demonstrated. The following protocol was designed to compare the effectiveness of orally and intramuscularly administered vitamin B12 in the treatment of patients ≥65 years of age with vitamin B12 deficiency. Methods/design The proposed study involves a controlled, randomised, multicentre, parallel, non-inferiority clinical trial lasting one year, involving 23 primary healthcare centres in the Madrid region (Spain), and patients ≥65 years of age. The minimum number of patients required for the study was calculated as 320 (160 in each arm). Bearing in mind an estimated 8-10% prevalence of vitamin B12 deficiency among the population of this age group, an initial sample of 3556 patients will need to be recruited. Eligible patients will be randomly assigned to one of the two treatment arms. In the intramuscular treatment arm, vitamin B12 will be administered as follows: 1 mg on alternate days in weeks 1 and 2, 1 mg/week in weeks 3–8,and 1 mg/month in weeks 9–52. In the oral arm, the vitamin will be administered as: 1 mg/day in weeks 1–8 and 1 mg/week in weeks 9–52. The main outcome variable to be monitored in both treatment arms is the normalisation of the serum vitamin B12 concentration at weeks 8, 26 and 52; the secondary outcome variables include the serum concentration of vitamin B12 (in pg/ml), adherence to treatment, quality of life (EuroQoL-5D questionnaire), patient 3satisfaction and patient preferences. All statistical tests will be performed with intention to treat and per protocol. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in analyses. Discussion The results of this study should help establish, taking quality of life into account, whether the oral administration of vitamin B12 is an effective alternative to its intramuscular administration. If this administration route is effective, it should provide a cheaper means of treating vitamin B12 deficiency while inducing fewer adverse effects. Having such an alternative would also allow patient preferences to be taken into consideration at the time of prescribing treatment. Trial registration This trial has been registered with ClinicalTrials.gov, number NCT 01476007, and under EUDRACT number 2010-024129-20.

2012-01-01

392

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 ...

393

VITAMIN B6, B12 AND FOLIC ACID SUPPLEMENTATION AND COGNITIVE FUNCTION: A SYSTEMATIC REVIEW OF RANDOMIZED TRIALS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Despite their important role in cognitive function, the value of B vitamin supplementation is unknown. A systematic review of the effect of vitamins B6, B12, and folic acid supplementation on cognitive function was performed. Literature search conducted in MEDLINE with supplemental articles from re...

394

Homocysteine and coronary artery disease in French Canadian subjects: Relation with vitamins B 12, B 6, pyridoxal phosphate, and folate  

Microsoft Academic Search

We determined plasma levels of homocysteine in 584 healthy subjects (380 men and 204 women) from a major utility company in the province of Que´bec, Canada, and in 150 subjects (123 men and 27 women) with angiographically documented coronary artery disease (CAD) (age < 60 years). Plasma levels of vitamins B12, B6, pyridoxal phosphate (a vitamin B6 derivative), and folate

Karl Dalery; Suzanne Lussier-Cacan; Jacob Selhub; Jean Davignon; Yves Latour; Jacques Genest

1995-01-01

395

Suppression of Homocysteine Levels by Vitamin B12 and Folates: Age and Gender Dependency in the Jackson Heart Study  

PubMed Central

Objectives To examine factors potentially contributing to premature cardiovascular disease mortality in African Americans (40% versus 20% all other populations), plasma homocysteine, serum vitamin B12 and folate levels were examined for African American participants in the Jackson Heart Study. Methods Of 5,192 African American Jackson Heart Study participants (21–94 years), 5,064 (mean age, 55±13 years; 63% female) had homocysteine levels measured via fasting blood samples, with further assessments of participants’ vitamin B12 (n=1,790) and folate (n=1,788) levels. We used regression analyses to examine age, gender, vitamin B12, and folate with homocysteine levels. Results Homocysteine levels, a purported surrogate risk factor for cardiovascular disease, increased with age, were inversely proportional to folate and vitamin B12 levels (p<0.001), and higher for men of all ages. Conclusions Our results show that, as with other populations, age, gender, vitamin B12, and folate may predict homocysteine levels for African Americans. Diet may be an important predictive factor as well, given the relationships we observed between plasma homocysteine and serum B vitamin levels.

Henry, Olivia R.; Benghuzzi, Hamed; Taylor, Herman A.; Tucci, Michelle; Butler, Kenneth; Jones, Lynne

2011-01-01

396

Fraction of Total Plasma Vitamin B12 Bound to Transcobalamin Correlates with Cognitive Function in Elderly Latinos with Depressive Symptoms  

PubMed Central

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: We assessed associations between cognitive function and total B12, holoTC, and holoTC/B12 ratio in a cohort of elderly Latinos (n = 1089, age 60–101 years). We assessed cognitive function using the Modified Mini-Mental State Examination (3MSE) and a delayed recall test; we diagnosed clinical cognitive impairment by neuropsychological and clinical exam with expert adjudication; and we assessed depressive symptoms using the Center for Epidemiological Studies Depression Scale (CES-D). We measured total B12 and holoTC using radioassays. RESULTS: HoloTC/B12 ratio was directly associated with 3MSE score (P = 0.026) but not delayed recall score. Interactions between holoTC/B12 and CES-D score were observed for 3MSE (P = 0.026) and delayed recall scores (P = 0.013) such that associations between the ratio and cognitive function scores were confined to individuals with CES-D ?16. For individuals with CES-D ?16, the odds ratio for clinical cognitive impairment for the lowest holoTC/B12 tertile was 3.6 (95% CI 1.2–11.2) compared with the highest tertile (P = 0.03). We observed no associations between cognitive function and total B12 or holoTC alone, except between holoTC and 3MSE score (P = 0.021), and no interactions between holoTC or total B12 and CES-D score on cognitive function. CONCLUSIONS: HoloTC/B12 ratio is associated with cognitive function in elderly Latinos with depressive symptoms and may better reflect the adequacy of B12 for nervous system function than either holoTC or total B12 alone.

Garrod, Marjorie G.; Green, Ralph; Allen, Lindsay H.; Mungas, Dan M.; Jagust, William J.; Haan, Mary N.; Miller, Joshua W.

2009-01-01

397

Deficiencies of the Microelements, Folate and Vitamin B12 in Women of the Child Bearing Ages in Gorgan, Northern Iran  

PubMed Central

Background: The deficiencies of folic acid, vitamin B12, and microelements during pregnancy may affect the health of newborns. Objectives: To assess the serum levels of folate, vitamin B12, iron, zinc and copper in healthy women of the childbearing ages in Gorgan, northern Iran. Methodology: This descriptive, cross-sectional study was carried out on 100 women of childbearing ages in northern Iran during November 2007-March 2008. The serum levels of folate, vitamin B12, iron, copper and zinc were evaluated by laboratory tests. Results: Iron, copper , folate, vitamin B12 deficiencies and folate with vitamin B12 deficiency were detected in 13%, 32% , 13% , 32% and 11% women of the childbearing ages, respectively . According to the ethnicity, vitamin B12, folate and iron deficiencies in the Sistani group were observed in 38.3%, 12.9% and 12.9% of the women, respectively. In the native Fars group, the above mentioned deficiencies were found in 31.1%, 13.4% and 7.5% of the subjects. Folate and vitamin B12 deficiencies were observed in the urban habitant in 32.7% and 11.5 % of the subjects as compared to those in the rural habitant (in 30.4% and 15.2%of the subjects respectively). The folate deficiencies in the under and above 18 years old subjects were 22.2% and 9.9%, respectively. Conclusions: This study showed that the deficiency of the micronutrients was considerable in women of the childbearing ages in Gorgan, northern Iran.

Sedehi, Maliheh; Behnampour, Naser; Golalipour, Mohammad Jafar

2013-01-01

398

Impact of Vitamin B12 on Formation of the Tetrachloroethene Reductive Dehalogenase in Desulfitobacterium hafniense Strain Y51  

PubMed Central

Corrinoids are essential cofactors of reductive dehalogenases in anaerobic bacteria. Microorganisms mediating reductive dechlorination as part of their energy metabolism are either capable of de novo corrinoid biosynthesis (e.g., Desulfitobacterium spp.) or dependent on exogenous vitamin B12 (e.g., Dehalococcoides spp.). In this study, the impact of exogenous vitamin B12 (cyanocobalamin) and of tetrachloroethene (PCE) on the synthesis and the subcellular localization of the reductive PCE dehalogenase was investigated in the Gram-positive Desulfitobacterium hafniense strain Y51, a bacterium able to synthesize corrinoids de novo. PCE-depleted cells grown for several subcultivation steps on fumarate as an alternative electron acceptor lost the tetrachloroethene-reductive dehalogenase (PceA) activity by the transposition of the pce gene cluster. In the absence of vitamin B12, a gradual decrease of the PceA activity and protein amount was observed; after 5 subcultivation steps with 10% inoculum, more than 90% of the enzyme activity and of the PceA protein was lost. In the presence of vitamin B12, a significant delay in the decrease of the PceA activity with an ?90% loss after 20 subcultivation steps was observed. This corresponded to the decrease in the pceA gene level, indicating that exogenous vitamin B12 hampered the transposition of the pce gene cluster. In the absence or presence of exogenous vitamin B12, the intracellular corrinoid level decreased in fumarate-grown cells and the PceA precursor formed catalytically inactive, corrinoid-free multiprotein aggregates. The data indicate that exogenous vitamin B12 is not incorporated into the PceA precursor, even though it affects the transposition of the pce gene cluster.

Reinhold, Anika; Westermann, Martin; Seifert, Jana; von Bergen, Martin; Schubert, Torsten

2012-01-01

399

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

400

AMN Directs Endocytosis of the Intrinsic Factor-Vitamin B12 Receptor Cubam by Engaging ARH or Dab2  

PubMed Central

Cubam is a multi-ligand receptor involved in dietary uptake of intrinsic factor-vitamin B12 in the small intestine and reabsorption of various low-molecular-weight proteins (such as albumin, transferrin, apolipoprotein A-I and vitamin D-binding protein) in the kidney. Cubam is composed of two proteins: cubilin and amnionless. Cubilin harbors ligand binding capabilities, while amnionless provides membrane anchorage and potential endocytic capacity via two FXNPXF signals within the cytosolic domain. These signals are similar to the FXNPXY signals found in members of the low-density lipoprotein receptor superfamily, which associate with clathrin-associated sorting proteins, including Disabled-2 (Dab2) and autosomal recessive hypercholesterolemia (ARH), during endocytosis. We therefore investigated the functionality of each amnionless FXNPXF signal and their respective interaction with sorting proteins. By sequential mutation and expression of a panel of amnionless mutants combined with yeast two-hybrid analyses, we demonstrate that the signals are functionally redundant and both are able to mediate endocytosis of cubam through interaction with Dab2 and ARH.

Pedersen, Gitte Albinus; Chakraborty, Souvik; Stinhauser, Amie L.; Traub, Linton M.; Madsen, Mette

2010-01-01

401

AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2.  

PubMed

Cubam is a multi-ligand receptor involved in dietary uptake of intrinsic factor-vitamin B(12) in the small intestine and reabsorption of various low-molecular-weight proteins (such as albumin, transferrin, apolipoprotein A-I and vitamin D-binding protein) in the kidney. Cubam is composed of two proteins: cubilin and amnionless. Cubilin harbors ligand binding capabilities, while amnionless provides membrane anchorage and potential endocytic capacity via two FXNPXF signals within the cytosolic domain. These signals are similar to the FXNPXY signals found in members of the low-density lipoprotein receptor superfamily, which associate with clathrin-associated sorting proteins, including Disabled-2 (Dab2) and autosomal recessive hypercholesterolemia (ARH), during endocytosis. We therefore investigated the functionality of each amnionless FXNPXF signal and their respective interaction with sorting proteins. By sequential mutation and expression of a panel of amnionless mutants combined with yeast two-hybrid analyses, we demonstrate that the signals are functionally redundant and both are able to mediate endocytosis of cubam through interaction with Dab2 and ARH. PMID:20088845

Pedersen, Gitte Albinus; Chakraborty, Souvik; Steinhauser, Amie L; Traub, Linton M; Madsen, Mette

2010-01-18

402

Anaerobic synthesis of vitamin B12: characterization of the early steps in the pathway.  

PubMed

The anaerobic biosynthesis of vitamin B12 is slowly being unravelled. Recent work has shown that the first committed step along the anaerobic route involves the sirohydrochlorin (chelation of cobalt into factor II). The following enzyme in the pathway, CbiL, methylates cobalt-factor II to give cobalt-factor III. Recent progress on the molecular characterization of this enzyme has given a greater insight into its mode of action and specificity. Structural studies are being used to provide insights into how aspects of this highly complex biosynthetic pathway may have evolved. Between cobalt-factor III and cobyrinic acid, only one further intermediate has been identified. A combination of molecular genetics, recombinant DNA technology and bioorganic chemistry has led to some recent advances in assigning functions to the enzymes of the anaerobic pathway. PMID:16042604

Frank, S; Brindley, A A; Deery, E; Heathcote, P; Lawrence, A D; Leech, H K; Pickersgill, R W; Warren, M J

2005-08-01

403

Anemia in urban underprivileged children. Iron, folate, and vitamin B12 nutrition.  

PubMed

The prevalence and type of nutritional anemia was investigated in 344 children aged 1 to 16 years of mixed race and living in a poor urban setting. Iron deficiency anemia was common in 1-year-old children (23%) as was biochemical evidence of iron deficiency (53%). Anemia rates were minimal in older children and the prevalence of iron deficiency decreased with age. Folate deficiency did not appear to contribute to the etiology of anemia, and nutritional vitamin B12 deficiency was not present. No-relationship could be found between a number of familial variables and hematological nutritional status. It is suggested that to identify families whose children are at risk for nutritional anemia new approaches will be needed to define their characteristics. PMID:868788

Margo, G; Baroni, Y; Green, R; Metz, J

1977-06-01

404

Vitamin B(12) metabolism during pregnancy and in embryonic mouse models.  

PubMed

Vitamin B(12) (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models. PMID:24025485

Moreno-Garcia, Maira A; Rosenblatt, David S; Jerome-Majewska, Loydie A

2013-09-10

405

Update on oral cyanocobalamin (vitamin B12) treatment in elderly patients.  

PubMed

The objective of this review is to evaluate the usefulness of oral cobalamin (vitamin B12) treatment in elderly patients. PubMed was systematically searched for English and French articles published from January 1990 to January 2007. Prospective randomized studies (n=3), a systematic review by the Cochrane group (n=1) and prospective studies in a well defined population (n=5) provide evidence that oral cobalamin therapy may adequately treat cobalamin deficiency in elderly patients. However, the current literature does not suggest a strategy in terms of the form (hydroxy- or cyanocobalamin), frequency and duration of the treatment. This review confirms the previously reported efficacy of oral cobalamin treatment in elderly patients. Oral cobalamin treatment avoids the discomfort, inconvenience and cost of monthly injections. PMID:18947260

Andrès, Emmanuel; Vogel, Thomas; Federici, Laure; Zimmer, Jacques; Kaltenbach, Georges

2008-01-01

406

CdTe quantum dot as a fluorescence probe for vitamin B12 in dosage form  

NASA Astrophysics Data System (ADS)

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%.

Vaishnavi, E.; Renganathan, R.

2013-11-01

407

Vitamin B12 Metabolism during Pregnancy and in Embryonic Mouse Models  

PubMed Central

Vitamin B12 (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.

Moreno-Garcia, Maira A.; Rosenblatt, David S.; Jerome-Majewska, Loydie A.

2013-01-01

408

The cis influence of the corrin in vitamin B12 models  

NASA Astrophysics Data System (ADS)

Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) calculations on [NH3[Co(III)(C10-X-corrin)]-CH3]+, where the C10-H of corrin is replaced by electron-donating or -withdrawing groups, X, explore the cis influence in these vitamin B12 models. As the electron donating ability of X increases, a normal trans influence is observed: the Co-NH3 bond weakens while the Co-CH3 bond strengthens. Surprisingly, though, the Co-CH3 bond dissociation energy decreases monotonically as the Co-C bond strengthens. This is found to be a consequence of the extent of shortening of the Co-NH3 during the homolysis reaction.

Govender, Penny P.; Navizet, Isabelle; Perry, Christopher B.; Marques, Helder M.

2012-10-01

409

What should I know before ordering a bone marrow aspiration/biopsy in patients with vitamin B12 deficiency?  

PubMed

Vitamin B12 deficiency is a well recognised cause of macrocytic anaemia and bone marrow failure. Bone marrow aspiration/biopsy is infrequently indicated for the diagnosis in this setting. However, if a bone marrow aspiration/biopsy is performed, it is important to recognise that it may show dysplastic changes mimicking myelodysplastic syndrome (MDS) or acute leukaemia. We report a case of a 66-year-old non-vegetarian man presenting with generalised weakness for 1 month and misdiagnosed on bone marrow biopsy as MDS. However, laboratory investigations revealed severe deficiency of vitamin B12. Four weeks after starting vitamin B12 replacement the patient's complete blood counts reverted to normal. PMID:23839610

Randhawa, Jaskirat; Ondrejka, Sarah L; Setrakian, Sebouh; Taylor, Harris

2013-07-08

410

Multiple micronutrient supplementation improves vitamin B12 and folate concentrations of HIV infected children in Uganda: a randomized controlled trial  

PubMed Central

Background The effect of multiple micronutrient supplementation on vitamin B12 and folate has hither to not been reported in African HIV infected children. This paper describes vitamin B12 and folate status of Ugandan HIV infected children aged 1-5 years and reports the effect of multiple micronutrient supplementation on serum vitamin B12 and folate concentrations. Methods Of 847 children who participated in a multiple micronutrient supplementation trial, 214 were assessed for vitamin B12 and folate concentrations pre and post supplementation. One hundred and four children were randomised to two times the recommended dietary allowance (RDA) of a 14 multiple micronutrient supplement (MMS) and 114 to a 'standard of care' supplement of 6 multivitamins (MV). Serum vitamin B12 was measured by an electrochemiluminescence immunoassay and folate by a competitive protein-binding assay using Modular E (Roche) automatic analyzer. Vitamin B12 concentrations were considered low if less than 221picomoles per litre (pmol/L) and folate if < 13.4 nanomoles per litre (nmol/L). The Wilcoxon Signed Ranks test was used to measure the difference between pre and post supplementation concentrations. Results Vitamin B12 was low in 60/214 (28%) and folate in 62/214 (29.0%) children. In the MMS group, the median concentration (IQR) of vitamin B12 at 6 months was 401.5 (264.3 - 518.8) pmol/L compared to the baseline of 285.5 (216.5 - 371.8) pmol/L, p < 0.001. The median (IQR) folate concentrations increased from 17.3 (13.5 - 26.6) nmol/L to 27.7 (21.1 - 33.4) nmol/L, p < 0.001. In the 'standard of care' MV supplemented group, the median concentration (IQR) of vitamin B12 at 6 months was 288.5 (198.8 - 391.0) pmol/L compared to the baseline of 280.0 (211.5 - 386.3) pmol/L while the median (IQR) folate concentrations at 6 months were 16.5 (11.7 - 22.1) nmol/L compared to 15.7 (11.9 - 22.1) nmol/L at baseline. There was a significant difference in the MMS group in both vitamin B12 and folate concentrations but no difference in the MV group. Conclusions Almost a third of the HIV infected Ugandan children aged 1-5 years had low serum concentrations of vitamin B12 and folate. Multiple micronutrient supplementation compared to the 'standard of care' supplement of 6 multivitamins improved the vitamin B12 and folate status of HIV infected children in Uganda. Trial registration http://ClinicalTrials.govNCT00122941)

2011-01-01

411

Effect of Vegetarianism and Smoking on Vitamin B12, Thiocyanate, and Folate Levels in the Blood of Normal Subjects  

Microsoft Academic Search

Vitamin B12, thiocyanate, and folate levels in the blood were estimated in 69 apparently normal subjects, of whom 26 were non-vegetarian non-smokers, 19 non-vegetarian smokers, 15 vegetarian non-smokers, and nine vegetarian smokers. The serum total (cyanide-extracted) B12 level (value A) ranged from 105 to 728 pg\\/ml, with a mean of 292 pg\\/ml. The highest values were found in non-vegetarian non-smokers

D. K.