Abstract
The first half of the study deals with the establishment of the laboratory procedure and conditions for measuring ^<57>Co and ^<60>Co in fecal matter, particularly with regard to the gamma spectrometric separation of the two isotopes and necessary corrections. The second half is concerned with the measurement of intestinal absorption of hydroxocobalamin-^<57>Co in comparison with cyanocobalamin-^<60>Co in rats following oral administration, and organ uptakes of radioactivity. No difference was obtained in the absolute amount of absorption between the two analogues, but the radioactivity uptakes by the liver and kidney were greater following administration of hydroxocobalamin-^<57>Co than cyanocobalamin-^<60>Co.
