Absorption of Vitamin B12 from the Colon of the Pig

Abstract
Six pigs were provided with colon cannulas introduced into the first portion of the colon via the cecum. Vitamin B12 labeled with Co57 was introduced into the colon. By the collection of feces and urine during a 7-day period, together with analysis of organ tissue, it was demonstrated that 41.6 to 58.0% of the radioactive cobalt was absorbed. Based upon the charcoal adsorption of radioactivity present in the feces, it appeared that some vitamin B12 was metabolized during its passage through the lower digestive tract.