Effect of Intrinsic Factor Concentrate upon Utilization of Orally Administered Vitamin B12 by Rats.

Abstract

Cobalt-60 labeled vit. B12 was fed orally to normal and B12 depleted rats at 2 levels (0.4 mg and 4.2 mg/rat) with and without concomitant clinically active intrinsic factor concentrate. Measurements of the radioactivity of kidneys, livers and urine indicate lowered absorption in the presence of intrinsic factor concentrate. Fecal excretion is too variable to permit reliable conclusions. Injection of a massive dose of normal B12 4 days after oral labeled vitamin liberates small amounts of additional radioactivity and again indicates an inhibitory effect of intrinsic factor concentrate.