Vegetarianism and vitamin B-12 (cobalamin) deficiency

Cobalamin (vitamin B(12)) biosynthesis in Rhodobacter capsulatus.

In Rhodobacter capsulatus, cobalamin biosynthesis has been shown to occur when the bacteria are grown either aerobically or anaerobically. However, a comparison of the main cobalamin biosynthetic operon found within R. capsulatus would suggest that the encoded proteins belong to the oxygen-dependent pathway for cobalamin biosynthesis, although, significantly, no homologue of the essential mono-...

Spirulina Pacifica as a Source of Cobalamin Vitamin B-12

Nitrous oxide-induced vitamin B(12) deficiency.

Two patients with asymptomatic vitamin B(12) deficiency developed a peripheral neuropathy 6-7 weeks after exposure to nitrous oxide during general anaesthesia, and 3 and 11 days after receiving cyclophosphamide. The serum B(12) concentration was less than 20 pmol/l and the symptoms resolved after B(12) replacement. We believe that the neurological symptoms were triggered by exposure to nitrous ...

[Neurological manifestations in Vitamin B 12 deficiency].

Vitamin B-12 deficiency is a common problem encountered in developing countries of the world. In Europe and North America it is frequently encountered in the elderly and in people whose diets are compromised such as alcoholics. Recent data has shown that cobalamin deficiency may occur in 5% to 40% of the general population. The prevalence as stated earlier is higher in the elderly and in nursin...

How I treat cobalamin (vitamin B12) deficiency.

The challenges in medical management of cobalamin deficiency lie in attention to the unique pathophysiology that underlies cobalamin deficiency, more than in the mechanics of therapy. The central physiologic principles are that clinically important deficiency is more likely to occur (and progress) when intrinsic factor-driven absorption fails than when diet is poor and that most causes take yea...