Clinical chemistry of vitamin B12.

  title={Clinical chemistry of vitamin B12.},
  author={R. E. Davis},
  journal={Advances in clinical chemistry},
  • R. Davis
  • Published 1985
  • Medicine
  • Advances in clinical chemistry
Role of vitamins in the metabolic syndrome and cardiovascular disease
This review investigated chemical basics, physiological effect and recommended daily intake, problems with deficiency and overdose, preclinical and clinical studies, and mechanisms of action of vitamin supplementation in the treatment and prevention of metabolic syndrome and cardiovascular disease.
Vitamin B-6 deficiency vs folate deficiency: comparison of responses to methionine loading in rats.
The plasma homocysteine response to methionine loading was assessed in vitamin B-6- and folate-deficient rats and results have significant bearing on the interpretation of both positive and negative responses to methIONine loading in humans.
Comparison between Serum Holotranscobalamin and Total Vitamin B12 as Indicators of Vitamin B12 Status.
It can be recommended that holoTC and total vitamin B12, alone and in combination, have almost equal diagnostic efficiency in screening/diagnosing vitamin B 12 deficiency for the majority of patients.
Vitamin B (Water Soluble)
  • 2011
The B Group of Vitamins is characterized by solubility in water, a feature that separates them from Vitamins A, D, E and K. It is not so clear why Vitamin C has always been kept out of this group and
Methylmalonic Acid and Homocysteine in Plasma as Indicators of Functional Cobalamin Deficiency in Infants on Macrobiotic Diets
It is concluded that the determination of methylmalonic acid and total homocysteine represents a sensitive and specific test for the diagnosis and follow-up of nutritional cobalamin deficiency in infants.
Redox status and protein binding of plasma homocysteine and other aminothiols in patients with hyperhomocysteinemia due to cobalamin deficiency.
The amount of protein-bound homocysteine was negatively correlated with the concentrations of bothprotein-bound cysteine and cysteinylglycine, indicating displacement of these aminothiols by homocy Steine, suggesting redox equilibrium between different aminothsiol species.
Compartmentalization of pyridoxal-5′-phosphate during the acute phase of myocardial infarction
It was found that the approximately 40% fall in plasma PLP levels was accompanied by an equivalent increase in RBCPLP levels, which enhanced the proposed storage function of RBCs for PLP and PL which is said to be an important source for muscle vitamin B6 which again is essential for energy production by the muscle cells during ischemia.
Vitamin B12 levels in familial Mediterranean fever patients treated with colchicine.
The authors did not observe significant vitamin B12 deficiency among colchicine-treated FMF patients but some cases may be more prone to developing this potentially serious disorder.
Kynurenic Acid and Xanthurenic Acid Excretion After Tryptophan Loading in Actinic Reticuloid
It is concluded that KA, which has been shown to have phototoxic properties in vitro, is not altered primarily in AR, and that the reported abnormalities of TRP metabolism are most tikely the consequence of the severe photosensitivity in this disorder.


Biochemical assessment of the nutritional status of vitamin B 6 in the human.
It has been found that the human body stores only a small amount of Vitamin-B6 and can quickly be depleted of this vitamin, and transaminase activities in erythrocytes leukocytes and plasma have been used as measurements of Vitamin -B6 nutritional status.
Vitamin B12 requirement of adult man.
Vitamin B6 status of the hospitalized aged.
  • S. VirA. Love
  • Medicine
    The American journal of clinical nutrition
  • 1978
A higher recommended allowance of vitamin B6 for the aged male and female subjects was considered desirable and all the biochemical parameters used for evaluating vitamin B 6 status appeared higher in females, but no statistical difference between male andFemale groups was noted.
Evidence regarding the minimal daily requirement of dietary vitamin B12.
It is concluded that the minimal daily requirement of dietary vitamin B12 for the average south Indian adult is in the region of 0.5 microgram/day and that an intake of 1.0 micro gram/day would cover the needs of the vast majority of the population and allow a wide margin of safety.
Vitamin B6 nutritional status of a group of female adolescents.
The vitamin B6 nutritional status of 127 females between the ages of 12 and 14 years was evaluated by nutrient intakes calculated from 24-hr dietary recalls, by measurement of erythrocyte alanine
Low serum vitamin B12 levels in patients receiving ascorbic acid in megadoses: studies concerning the effect of ascorbate on radioisotope vitamin B12 assay.
This study demonstrates that serum B,2 determinations performed without added KCN may be low due to the presence of ascorbate in the serum, and that such low levels do not necessarily reflect tissue deficiency of the vitamin.
Vitamin requirements in patients receiving total parenteral nutrition.
This study represents an initial attempt to define intravenous vitamin requirements in adult patients receiving total parenteral nutrition (TPN). We have investigated two different vitamin
Malabsorption of protein bound vitamin B12.
Defective absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects andMalabsorption of the vitamin from protein bound sources, which is not detected by the Schilling test, may produce vitamin B12 deficiency of clinical importance.
Vitamin-responsive inborn errors of metabolism.
  • C. Scriver
  • Biology
    Metabolism: clinical and experimental
  • 1973