The Effect of Ranitidine on the Absorption of Food Cobalamins

Abstract

The effect of the histamine H₂-receptor antagonist ranitidine on the absorption of food cobalamins was investigated in 20 healthy volunteers randomized to treatment with ranitidine or placebo for 1 week. Liver homogenates containing cobalamins labelled in vivo with cobalt-57 was obtained by repeated injections of ⁵⁷Co-labelled cyanocobalamin in rabbits. Test doses (0.37 nmol) of the ⁵⁷Co-labelled liver cobalamins were administered orally together with ⁵¹CrCl₃ and carmine red, and the absorption of ⁵⁷Co-labelled cobalamins was assessed from the ratio of the two isotopes in the stool collection that had been coloured by the carmine red. There was no significant difference in the mean absorption before (47.4%) and after (50.7%) the treatment.

Key Words:

• H₂-receptor blocker
• intestinal absorption
• vitamin B₁₂