Chromatographic and Bioautographic Estimation of Plasma Cobalamins in Various Disturbances of Vitamin B12 Metabolism

1. This paper reports a survey of values for individual plasma cobalamins in normal subjects, hospital controls, and patients with vitamin B12 deficiency and diseases in which there are disturbances of B12 metabolism. The values were obtained by thin-layer chromatography and bioautography followed by photometric scanning or visual assessment. 2. Normal plasma contains methylcobalamin (the predominant component), deoxyadenosylcobalamin and hydroxocobalamin. The latter two compounds are not separable in the solvent system routinely used. In some samples there were traces of cyanocobalamin. The ratio of methylcobalamin to deoxyadenosylcobalamin plus hydroxocobalamin, normally greater than 1·0, was reduced in B12 deficiency. Many cases of untreated pernicious anaemia showed a high proportion (up to 40%) of cyanocobalamin. In folate deficiency there was no consistent change in individual cobalamins. Patients with leukaemias and liver disease showed a variety of changes, some attributable to alterations in plasma binding capacity and loss of deoxyadenosylcobalamin from the liver. 3. After oral or parenteral administration of cyanocobalamin, plasma cyanocobalamin increased and there was evidence of conversion to methylcobalamin. After parenteral administration of methylcobalamin, this compound increased in the plasma, but deoxyadenosylcobalamin plus hydroxocobalamin did not change. 4. Possible reasons for pathological changes in individual plasma cobalamins are discussed.

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The Effect of Vitamin B12 Deficiency on Methylfolate Metabolism and Pteroylpolyglutamate Synthesis in Human Cells

Clinical Science ◽

10.1042/cs0470617 ◽

1974 ◽

Vol 47 (6) ◽

pp. 617-630

Author(s):

A. Lavoie ◽

E. Tripp ◽

A. V. Hoffbrand

Keyword(s):

Folic Acid ◽

Vitamin B12 ◽

Direct Effect ◽

Vitamin B12 Deficiency ◽

Pernicious Anaemia ◽

Normal Subjects ◽

Normal Cells ◽

Methyl Group ◽

Consistent Effect ◽

B12 Deficiency

1. The uptake of 14C from [methyl-14C]methyItetrahydrofolate was significantly reduced in the phytohaemagglutinin (PHA)-stimulated lymphocytes from nine patients with untreated pernicious anaemia compared with the uptake in seven normal subjects. 2. The uptake of 14C from [14C]methyltetrahydrofolate by the lymphocytes from seven of the patients with pernicious anaemia was consistently increased by addition of vitamin B12in vitro. 3. The proportion of 14C taken up from [14C]methyltetrahydrofolate transferred to non-folate compounds was found to be significantly reduced in the PHA-stimulated lymphocytes from nine patients with untreated pernicious anaemia compared with the proportion transferred in the PHA-stimulated lymphocytes from seven normal subjects. Addition of vitamin B12in vitro consistently increased the transfer in vitamin B12-deficient cells but had no consistent effect in normal cells. 4. Normal and vitamin B12-deficient PHA-stimulated lymphocytes took up [3H]folic acid and after 72 h incubation converted this largely into pteroylpolyglutamate forms. 5. The proportion of labelled lymphocyte folate as pteroylpolyglutamate after incubation with [3H]folic acid was the same in vitamin B12-deficient as in normal lymphocytes and the proportion of pteroylpolyglutamates formed in vitamin B12-deficient lymphocytes was unaffected by addition of vitamin B12in vitro. 6. No radioactivity could be decteted in pteroylpolyglutamates after incubating normal PHA-stimulated lymphocytes with [14C]methyltetrahydrofolate for 72 h, suggesting that pteroylpolyglutamate forms of folate cannot be made directly from methyltetrahydrofolate. 7. These results are consistent with the ‘methyltetrahydrofolate trap’ hypothesis in vitamin B12 deficiency. It is suggested that reduced synthesis of pteroylpolyglutamates reported by others in vitamin B12-deficient cells may be secondary to the failure of removal of the methyl group from methyltetrahydrofolate rather than to a direct effect of vitamin B12 deficiency on the enzyme responsible for pteroylpolyglutamate synthesis. 8. Reduced entry of methyltetrahydrofolate into vitamin B12-deficient cells may be secondary to failure of conversion of this compound into tetrahydrofolate.

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The Danger of B12 Deficiency in the Elderly

Nutrition and Health ◽

10.1177/026010609801200402 ◽

1998 ◽

Vol 12 (4) ◽

pp. 215-226 ◽

Cited By ~ 11

Author(s):

Margaret Wynn ◽

Arthur Wynn

Keyword(s):

Nervous System ◽

Risk Factor ◽

Heart Disease ◽

Vitamin B12 ◽

Vitamin B12 Deficiency ◽

Pernicious Anaemia ◽

The Elderly ◽

Nerve Cells ◽

Accelerated Ageing ◽

B12 Deficiency

Vitamin B12 deficiency damages nerve cells and aggravates nervous system disorders even in the absence of evidence of anaemia. Prevalence of B12 deficiency increases with age especially over 65 and is frequently associated with Alzheimer's disease. Recent American surveys record a higher prevalence of B12 deficiency and of undiagnosed and untreated pernicious anaemia in the elderly than reported earlier. B12 deficiency is also reported to be a risk factor for heart disease, stroke and accelerated ageing.

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Circulating antibody to transcobalamin II causing retention of vitamin B12 in the blood

Blood ◽

10.1182/blood.v49.6.987.bloodjournal496987 ◽

1977 ◽

Vol 49 (6) ◽

pp. 987-1000 ◽

Cited By ~ 2

Author(s):

R Carmel ◽

B Tatsis ◽

L Baril

Keyword(s):

Vitamin B12 ◽

Binding Capacity ◽

Megaloblastic Anemia ◽

Serum Vitamin ◽

Vitamin B12 Deficiency ◽

High Serum ◽

The Status ◽

B12 Deficiency ◽

Long Acting

A patient with recurrent pulmonary abscess, weight loss, and alcoholism was found to have extremely high serum vitamin B12 and unsaturated vitamin B12-binding capacity (UBBC) levels. While transcobalamin (TC) II was also increased, most of his UBBC was due to an abnormal binding protein which carried greater than 80% of the endogenous vitamin B12 and was not found in his saliva, granulocytes, or urine. This protein was shown to be a complex of TC II and a circulating immunoglobulin (IgGkappa and IgGlambda). Each IgG molecule appeared to bind two TC II molecules. The reacting site did not interfere with the ability of TC II to bind vitamin B12, but did interfere with its ability to transfer the vitamin to cells in vitro. The site was not identical to that reacting with anti-human TC II antibody produced in rabbits. Because of this abnormal complex, 57Co-vitamin B12 injected intravenously was cleared slowly by the patient. However, no metabolic evidence for vitamin B12 deficiency was demonstrable, although the patient initially had megaloblastic anemia apparently due to folate deficiency. The course of the vitamin B12-binding abnormalities was followed over 4 yr and appeared to fluctuate with the status of the patient's illness. The IgG-TC II complex resembled one induced in some patients with pernicious anemia by intensive treatment with long-acting vitamin B12 preparations. The mechanism of induction of the antibody formation in our patient is unknown.

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

BMJ Case Reports ◽

10.1136/bcr-2013-200380 ◽

2013 ◽

Vol 2013 (sep29 1) ◽

pp. bcr2013200380-bcr2013200380 ◽

Cited By ~ 4

Author(s):

H. B. Gowdappa ◽

M. Mahesh ◽

K. V. K. S. N. Murthy ◽

M. G. Narahari

Keyword(s):

Spinal Cord ◽

Helicobacter Pylori ◽

Vitamin B12 ◽

Vitamin B12 Deficiency ◽

Pernicious Anaemia ◽

Subacute Combined Degeneration ◽

B12 Deficiency

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Differentiation between Vitamin B12—deficient and Folic Acid—deficient Megaloblastic Anemias with C14—Histidine

Blood ◽

10.1182/blood.v21.4.447.447 ◽

1963 ◽

Vol 21 (4) ◽

pp. 447-461 ◽

Cited By ~ 22

Author(s):

MATHEWS B. FISH ◽

MYRON POLLYCOVE ◽

THOMAS V. FEICHTMEIR

Keyword(s):

Folic Acid ◽

Vitamin B12 ◽

Specific Activity ◽

Megaloblastic Anemia ◽

Vitamin B12 Deficiency ◽

Normal Subjects ◽

Intermediary Metabolism ◽

Folic Acid Deficiency ◽

Acid Deficiency ◽

B12 Deficiency

Abstract Intermediary metabolism of the monocarbon pool and histidine in normal subjects and patients with megaloblastic anemia was studied by continuous measurement of pulmonary excretion of C14O2 and urinary excretion of C14 after injection of L-histidine-2(ring)-C14. Cumulative pulmonary and renal excretion of C14 for 1 month by two normal subjects approximates 45 per cent of the amount injected. Within 4 months after injection of the dose used in this study, the resultant average tissue radiation decreases below the average natural terrestrial and cosmic radiation level. Simultaneous determination of two parameters, (1) cumulative 1-hour pulmonary C14 excretion and (2) the time of occurrence of maximum C14O2specific activity (Tmax), may permit rapid and unequivocal differentiation between folic acid deficiency and vitamin B12 deficiency in the pathogenesis of megaloblastic anemia. Folio acid deficiency results in marked diminution of pulmonary C14 excretion (approximately 0.1 per cent of injection C14 in 1 hour) and marked prolongation of C14O2-specific activity Tmax (approximately 3 hours), while both parameters are normal (approximately 1 per cent and less than 1 hour, respectively) in patients with vitamin B12 deficiency and megaloblastic anemia. Measurement during periods of reticulocyte response to either folio acid or vitamin B12 demonstrate normal C14O2-specific activity Tmax but decreased pulmonary C14 excretion. These observations suggest that prolongation of C14O2-specific activity Tmax is a sensitive index of folic acid deficiency or block and that if Tmax is normal, pulmonary C14 excretion is a sensitive index of the relative partition of the active monocarbon pool between pathways for oxidation and pathways for nucleic acid synthesis. This type of breath analysis seems to provide a quantitative dynamic representation of metabolic function which may be particularly useful in differentiating between the alterations of intermediary metabolism that occur in patients with folic acid-deficient megaloblastic anemia and in patients with vitamin B12-deficient megaloblastic anemia.

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

Blood ◽

10.1182/blood.v34.6.774.774 ◽

1969 ◽

Vol 34 (6) ◽

pp. 774-781 ◽

Cited By ~ 5

Author(s):

CHRISTINE LAWRENCE

Keyword(s):

Molecular Weight ◽

Vitamin B12 ◽

Binding Capacity ◽

Gel Filtration ◽

Vitamin B12 Deficiency ◽

Normal Serum ◽

B12 Deficiency ◽

Abnormal Pattern ◽

Normal Controls

Abstract 57CoB12 was added to serum in vitro to study its binding by the three known serum B12-binders in patients with vitamin B12 deficiency and in normal controls. Gel filtration through columns of Sephadex G-200 was used to separate the low (beta) and high (alpha1 and beta) molecular weight B12-binding fractions. Electrophoresis on filter paper was used to separate the alpha1- and beta-globulins. The alpha1-globulin fraction in the serum of B12-deficient patients bound more of the added 57CoB12 than did this fraction in normal serum, presumably because this binder of the serum endogenous vitamin B12 is much less saturated in B12-deficiency. However, the total B12 binding capacity of the alpha1-globulin (for endogenous plus added vitamin B12) was lower in B12-deficient than in normal serum. The low molecular weight beta-binder bound more added 57CoB12 in B12-deficient than in normal serum, whereas the high molecular weight beta binder had a much lower B12-binding capacity in deficient than in normal serum. These abnormalities were independent of the cause of the vitamin B12 deficiency and disappeared after successful treatment with vitamin B12.

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A Case of Sub-acute Combined Degeneration of the Spinal Cord with Associated Pernicious Anaemia

Pulse ◽

10.3329/pulse.v5i1.20193 ◽

2014 ◽

Vol 5 (1) ◽

pp. 57-60 ◽

Cited By ~ 2

Author(s):

AA Bhuiyan ◽

SK Dash ◽

SMH Shahriar ◽

F Nahid ◽

S Arefin

Keyword(s):

Spinal Cord ◽

Vitamin B12 ◽

Intrinsic Factor ◽

Vitamin B12 Deficiency ◽

Pernicious Anaemia ◽

Bone Marrow Examination ◽

Chronic Atrophic Gastritis ◽

Endoscopic Biopsy ◽

B12 Deficiency ◽

Hands And Feet

Aim and Objective Vitamin B12 deficiency disease, specially associated with pernicious anaemia is a relatively rare disease in the developing countries. Patients with B12 deficiency may present with hematological, gastro-intestinal and neuro-psychiatric manifestations. Here we discuss a case of a fifty five-year-old lady presented with sub-acute combined degeneration of the spinal cord. Case presentation A fifty five year old female was admitted in Neurology ward in Apollo Hospitals, Dhaka from OPD for progressive quadriparesis with tingling in the hands and feet. She had no associated visual, bulbar symptoms, sphincter incontinence or memory impairment. Investigation revealed mild anaemia, macrocytosis on peripheral blood picture, low Vitamin B12 level with megaloblastic changes in bone marrow examination. Anti-Intrinsic factor antibody and anti-parietal cell antibody was not done, as it is not available here. MRI of dorsal spine shows T2 hyper-intense lesions in the posterior cord. GI Endoscopic biopsy revealed chronic atrophic gastritis. Conclusion We presented this case because of its relatively uncommon occurrence in our country. Sub-acute combined degeneration of spinal cord associated with dietary deficiency is common in Indian sub-continent. High index of suspicion is needed for its early diagnosis as delay in treatment can lead to poor neurological recovery. DOI: http://dx.doi.org/10.3329/pulse.v5i1.20193 Pulse Vol.5 January 2011 p.57-60

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Keeping a clear head with vitamin B12

The Biochemist ◽

10.1042/bio03206020 ◽

2010 ◽

Vol 32 (6) ◽

pp. 20-24

Author(s):

Elena Kazamia ◽

Katherine E. Helliwell ◽

Alison G. Smith

Keyword(s):

Vitamin B12 ◽

Dairy Products ◽

Vitamin B12 Deficiency ◽

Physiological Role ◽

Pernicious Anaemia ◽

Increased Risk ◽

B12 Deficiency ◽

The Subject ◽

Enzyme Cofactors ◽

Essential Enzyme

Vitamins are vital organic micronutrients that are required in our diet because they provide essential enzyme cofactors, and animals have dispensed with the ability to synthesize them. Vitamin B12, or cobalamin, is the most complex of the vitamins, and the elucidation of its physiological role, its structure and its biosynthetic pathways have been the subject of impressive scientific endeavours over the years. Vitamin B12 deficiency leads to increased risk of cardiovascular disease, neurological symptoms and, in the most serious cases, pernicious anaemia. Cobalamin is synthesized only by prokaryotes, so we obtain it second-hand by eating other organisms that have accumulated the vitamin in their tissues. The richest dietary sources are liver, dairy products and also algae, many of which are like animals in that they require an exogenous supply of the vitamin for growth.

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Severe Haemolytic Anaemia, a Rare Presentation of Nutritional Vitamin B12 Deficiency: A Case Report

Nepalese Medical Journal ◽

10.3126/nmj.v2i1.24556 ◽

2019 ◽

Vol 2 (1) ◽

pp. 188-190

Author(s):

Aamir Siddiqui

Keyword(s):

Case Report ◽

Vitamin B12 ◽

Hemolytic Anemia ◽

Megaloblastic Anemia ◽

Vitamin B12 Deficiency ◽

Pernicious Anaemia ◽

Rare Form ◽

Rare Presentation ◽

B12 Deficiency ◽

Nutritional Vitamin

Vitamin B12 deficiency usually presents with megaloblastic anemia, pancytopenia, and neurological symptoms. The cause is usually, nutritional deficiency, increase demand, decrease absorption. This report describes a case with symptoms of apathy and findings suggestive of severe hemolytic anemia, diagnosed with vitamin B12 deficiency. Haemolysis is a rare hematological finding in cases of B12 deficiency, and descriptions of a nutritional vitamin B12 deficiency, without evidence of pernicious anaemia, causing haemolysis, are even scarcer, and this paper was intended to draw physicians’ attention to this rare form of presentation.

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The Plasma Clearance and Urinary Excretion of Parenterally Administered 58Co B12

Blood ◽

10.1182/blood.v11.1.31.31 ◽

1956 ◽

Vol 11 (1) ◽

pp. 31-43 ◽

Cited By ~ 32

Author(s):

D. L. MOLLIN ◽

W. R. PITNEY ◽

S. J. BAKER ◽

J. E. BRADLEY

Keyword(s):

Urinary Excretion ◽

Vitamin B12 ◽

Plasma Clearance ◽

Vitamin B12 Deficiency ◽

Normal Subjects ◽

Normal Serum ◽

Chronic Myelocytic Leukemia ◽

Intravenous Injections ◽

Myelocytic Leukemia ◽

B12 Deficiency

Abstract Intravenous injections of 1.5 µg. of 58Co B12 were given to subjects with normal serum B12 concentrations, to patients with vitamin B12 deficiency and to patients with chronic myelocytic leukemia. The rate of plasma clearance of radioactivity after this dose was slowest in patients with chronic myelocytic leukemia and patients with pernicious anemia in severe relapse. In patients with vitamin B12 deficiency, serum B12 concentrations were estimated microbiologically at frequent intervals after the injection. There was a good correlation between the results obtained by microbiological assay and as calculated from plasma radioactivity. Significant differences were not observed between the urinary excretion of radioactivity by normal subjects and patients with B12 deficiency.

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