Effect of Intrinsic Factor Concentrate upon Utilization of Orally Administered Vitamin B 12 by Rats. ∗

Abstract

Summary

1. The effect of a clinically active intrinsic factor concentrate on the absorption of cobalt 60 labeled vit. B₁₂ by rats after oral administration has been studied. 2. Measurements of the radioactivity of kidneys, livers and urine indicate lowered absorption in the presence of intrinsic factor concentrate. Fecal radioactivity is too variable to permit reliable conclusions. 3. Injection of a massive dose (20 μg) of normal B₁₂ 4 days after oral administration of the labeled vitamin liberates additional urinary radioactivity, and again points to an inhibitory effect of intrinsic factor concentrate.