Gastrointestinal Absorption and Urinary Excretion of Vitamin B 12 -Co 60 . ∗

Abstract

Summary and Conclusions

1. Following oral administration of vit. B₁₂-Co⁶⁰ to normal individuals and subsequent “flushing” by subcutaneous injection of cobalamin, the radioactive material could be extracted from urine by n-butanol; the Co⁶⁰ containing substance had the same distribution coefficient between ammonium sulfate saturated urine and n-butanol as authentic vit. B₁₂-Co^60. 2. In an aqueous 2, 4-lutidine system the radioactive material in the urine has the same Rf value as pure vit. B₁₂ and vit. B₁₂-Co^60. 3. Our studies support the view that the Schilling test measures absorption of vit. B₁₂-Co⁶⁰ from the gut rather than absorption of decomposition products. Its use therefore as an assay of intrinsic factor appears justified.