Hydroxocobalamin. II. Absorption from the Site of Injection and Uptake by the Liver and Calf Muscle in Man

Labeled hydroxocobalamin, administered intramuscularly in man, is absorbed more slowly from the site of injection and deposited in the liver and calf muscle to a degree equal to or higher than that of cyanocobalamin at an equivalent dose. These findings, together with those reported in Part I of this paper, suggest the applicability of hydroxocobalamin as a long-acting vitamin B₁₂ in man. These conclusions, however, require the support to be obtained from long-range observations on patients with vitamin B₁₂ depletion.