Urinary Excretion of Vitamin B12, folic Acid, and Citrovorum actor in Human Subjects on Various Diets.

Abstract
The avg. urinary excretion of vit. B12 in 14 subjects on normal diets was 31 m[mu]g. per day. Similar values were obtained in 28 subjects maintained for 3 days on the following diets: milk, alkaline ash, low protein, and high protein. A somewhat higher value was found in 8 subjects on high purine diets, the increase over normal being due to interfering compounds. On the 3d day of fasting 6 subjects excreted an average of 62 m[mu]g. vit. B12 per day. The average citrovorum factor (CF) excretion by the subjects on the above diets accounted for only part of the total folic acid (FA) compounds excreted, and was apparently correlated with the total FA values. Differences in vit. B12 excretion resulting from dietary changes were not similar to those observed in CF and FA excretion.