Cobalamin forms in plasma and tissue during treatment of vitamin B12 deficiency.

Thin-layer chromatography and bioautography were used to study the cobalamin pattern of plasma, erythrocytes, and hepatic tissue from patients with cobalamin deficiency on maintenance therapy with hydroxocobalamin (Vibeden), a cyanocobalamin depot preparation (Betolvex), or cyanocobalamin tablets (Behepan). The cobalamin pattern in plasma is dominated by the form in which it is administered. The results of assaying the erythrocytes and liver biopsies show that the cobalamins administered are converted to the coenzyme forms in vivo, irrespective of the type of cobalamin preparation.