Factors affecting the Absorption of Vitamin B12

1972 ◽  
Vol 43 (2) ◽  
pp. 233-250 ◽  
Author(s):  
J. F. Adams ◽  
D. J. Clow ◽  
Sheila K. Ross ◽  
K. Boddy ◽  
Priscilla King ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Intrinsic Factor ◽  
Pernicious Anaemia ◽  
Whole Body ◽  
Factors Affecting ◽  
Control Subjects ◽  
Tracer Techniques ◽  
Receptor Sites ◽  
Body Counting ◽  
Dose Levels

1. The absorption of radioactive cobalamin was measured by a whole-body counting technique in control subjects and in patients with pernicious anaemia. 2. The absorption of cyanocobalamin by patients with pernicious anaemia was decreased by charcoal but not by bile or saliva. 3. The absorption of cyanocobalamin by control subjects was not affected by food but was significantly increased by pentagastrin. With pentagastrin the absorption of cyanocobalamin was significantly greater than that of hydroxocobalamin. The hog intrinsic factor-mediated absorption of cyanocobalamin by patients with pernicious anaemia was significantly depressed by pentagastrin. 4. The effect of increasing the mass of hog intrinsic factor concentrate on the absorption of cyanocobalamin by patients with pernicious anaemia could be described by a function relating the amount absorbed, the mass of intrinsic factor and two constants. The relationship implies that when the mass of intrinsic factor is small the amount of cyanocobalamin absorbed is directly proportional to the mass of intrinsic factor but that absorption approaches a saturation value with increasing mass of intrinsic factor. In physiological terms the function implies that absorption is proportional to the amount of cyanocobalamin attached to receptor sites but that cyanocobalamin attached to receptor sites may become detached and either reattached or lost to absorption. 5. With oral doses of 25 μg and 50 μg, control subjects absorbed more cyanocobalamin and hydroxocobalamin than patients with pernicious anaemia. At both dose levels control subjects absorbed more cyanocobalamin than hydroxocobalamin but no difference was observed in patients with pernicious anaemia. The intrinsic factor mechanism therefore influences amounts absorbed at such dose levels and appears to be a factor in the differences in absorption of cyanocobalamin and hydroxocobalamin. 6. The use of double-tracer techniques makes it possible for each subject to act as his own control in studies of vitamin B12 absorption. The value of this technique is stressed.

scholarly journals Measurement of Absorption of Vitamin B12 by Whole-Body Gamma Spectrometry

Blood ◽  
1961 ◽  
Vol 18 (1) ◽  
pp. 95-101 ◽  
Author(s):  
P. G. REIZENSTEIN ◽  
EUGENE P. CRONKITE ◽  
S. H. COHN
Keyword(s):  
Vitamin B12 ◽  
Intrinsic Factor ◽  
The Body ◽  
Whole Body ◽  
Radiochemical Analysis ◽  
Body Counting ◽  
Simple Measurement ◽  
Primary Advantage ◽  
Whole Body Counting ◽  
High Degree

Abstract A technic is described to measure directly the intestinal absorption of radiovitamin B12 by using a whole-body gamma spectrometer. A double tracer technic is used, and the amounts of free and intrinsic factor bound vitamin B12, respectively, retained in the body after final excretion of unabsorbed radioactivity, are measured. The results are in agreement with those previously obtained by other methods. The present method is simple and quantitative. The primary advantage of the whole-body counter for measuring absorption of Cobalt-labeled B12 is that it can measure less than 0.1 µc. with a high degree of accuracy. Whole-body counting substitutes a rapid and simple measurement for the difficult and tedious collection and radiochemical analysis of excreta.

Long-Term Clearance of [57Co]Cyanocobalamin in Vegans and Pernicious Anaemia

1980 ◽  
Vol 58 (1) ◽  
pp. 101-103 ◽  
Author(s):  
S. Amin ◽  
T. Spinks ◽  
A. Ranicar ◽  
M. D. Short ◽  
A. V. Hoffbrand
Keyword(s):  
Intrinsic Factor ◽  
Pernicious Anaemia ◽  
Normal Subjects ◽  
Whole Body ◽  
Least Squares Fit ◽  
Significant Difference ◽  
Maximum Period ◽  
Body Counting ◽  
Whole Body Counting

1. Whole-body counting has been used to monitor the clearance of [57Co]cyanocobalamin in normal subjects, vegans and patients with pernicious anaemia. After oral administration of 57Colabelled cyanocobalamin (1 μg/l μCi), subjects were counted for radioactivity monthly for a maximum period of 1 year. 2. The results obtained were consistent with a monoexponential clearance model and a least-squares fit showed that there was no significant difference between the mean clearance rates for the vegans and normal subjects. 3. The patients with pernicious anaemia cleared the vitamin significantly more quickly than the normal control subjects. 4. This may be due to failure to reabsorb biliary vitamin B12 in pernicious anaemia because of the absence of intrinsic factor.

Application of the Occupancy Principle in Studies of the Metabolism of Vitamin B12 in Man

1980 ◽  
Vol 58 (2) ◽  
pp. 169-171 ◽  
Author(s):  
R. G. Bessent ◽  
W. S. Watson ◽  
Caroline M. L. A. MacDonald ◽  
J. F. Adams
Keyword(s):  
Dietary Intake ◽  
Vitamin B12 ◽  
Body Mass ◽  
Pernicious Anaemia ◽  
Whole Body ◽  
Control Subjects

1. The long-term clearance of radioactive vitamin B12 from serum and from whole body was measured in control subjects and patients with treated pernicious anaemia and the data were analysed by the occupancy principle to provide estimates of dietary intake, daily requirements and whole-body mass of vitamin B12. 2. In six cases the daily requirement for vitamin B12 ranged from 0·15 to 1·9 μg with an average of 1·0 μg. The whole-body vitamin B12 in four cases ranged from 780 to 1350 μg with an average of 1060 μg. 3. Estimates of the whole-body vitamin B12 on the assumption of single-pool equilibrium gave constantly changing results, which, together with discrepant half-lives for serum radioactivity and whole-body radioactivity, constitute evidence against the concept of single-pool equilibrium.

scholarly journals Oral Treatment of Pernicious Anaemia with a Combined Vitamin B12 and Intrinsic Factor Preparation

BMJ ◽  
1955 ◽  
Vol 2 (4937) ◽  
pp. 461-463 ◽  
Author(s):  
E. K. Blackburn ◽  
H. Cohen ◽  
G. M. Wilson
Keyword(s):  
Vitamin B12 ◽  
Oral Treatment ◽  
Intrinsic Factor ◽  
Pernicious Anaemia

Whole Body Counting of Vitamin B12 58Co Absorption Supplemented by Profile Scanning

1970 ◽  
Vol 5 (4) ◽  
pp. 261-264
Author(s):  
N. D. C. Finlayson ◽  
J. D. Simpson ◽  
D. J. C. Shearman
Keyword(s):  
Vitamin B12 ◽  
Whole Body ◽  
Body Counting ◽  
Whole Body Counting

scholarly journals Total Body Counting in the Assessment of Vitamin B12 Absorption in Patients with Pernicious Anemia, Achlorhydria Without Pernicious Anemia and in Acid Secretors

Blood ◽  
1970 ◽  
Vol 36 (1) ◽  
pp. 20-27 ◽  
Author(s):  
W. J. IRVINE ◽  
D. R. CULLEN ◽  
LAURA SCARTH ◽  
J. D. SIMPSON ◽  
S. H. DAVIES
Keyword(s):  
Vitamin B12 ◽  
Pernicious Anemia ◽  
Intrinsic Factor ◽  
Body Counting ◽  
Acid Secreting ◽  
Vitamin B12 Absorption ◽  
Upper Level ◽  
Equivocal Result ◽  
Total Body ◽  
Cent Error

Abstract The absorption of 58Co-vitamin B12 was assessed by the method of total body counting in 25 patients with frank P.A., five with latent P.A., 47 with achlorhydria but without malabsorption of vitamin B12 and 47 acid-secreting patients. A total of 192 tests was done. With or without prior stimulation of intrinsic factor secretion by pentagastrin the upper level of absorption of vitamin B12 in patients with frank or latent P.A. was 25 per cent. Taking an equivocal result to be 21-25 per cent inclusive, the total body counting method was able to distinguish P.A. patients from those with achlorhydria without P.A. with 87 per cent accuracy and one per cent error and from non-P.A. achlorhydric patients and acid secretors combined with 91 per cent accuracy and 0.5 per cent error. Pentagastrin stimulation did not improve the separation between achlorhydric patients with and without P.A. but raised the lower limit of retention of vitamin B12 from 24 to 44 per cent in the acid secreting patients. The method of total body counting is recommended as a method of assessing vitamin B12 absorption.

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

Pulse ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 57-60 ◽  
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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