The combination of some vitamin B12-like compounds with sow's milk whey and ‘intrinsic factor’ concentrates

Abstract
Optical density measurements were used to determine the concns. of solns. of ionophor-etically pure vit. B12, factors A and B and pseudovit. B12- From these measurements the microbiological activities for Bacterium coli, in a tube assay, were established. Factor A had 66%, factor B 22% and pseudovit. B12 8% of the growth activity of vit. B12 . The amts. of these factors which combined with an "intrinsic factor" concentrate and a sow''s whey concentrate were identical with the amt. of vit. B12 "bound".