Alteration of Plasma Clearance of Vitamin B 12 by Intravenous Hog Intrinsic Factor Concentrate. ∗

Summary

1. Studies of the fate of intravenously injected vitamin B₁₂ bound to hog intrinsic factor concentrate have been performed in patients with pernicious anemia and malabsorption syndrome. 2. The abnormal plasma disappearance curves of vit B₁₂ in pernicious anemia and malabsorption syndrome became normal after incubation of B₁₂ with hog intrinsic factor concentrate. 3. Plasma clearance of radioactivity in pernicious anemia is slower following injection of intrinsic factor labeled with I¹³¹ than following injection of intrinsic factor labeled with radiocobalt-B₁₂. 4. A specific effect of intrinsic factor in transferring circulating vit B₁₂ to the liver is discussed.