Synthesis of Vitamins in the Human Gut

to hand, and it appears to be one of growing importance. We therefore refer to the subject again. The idea that vitamins could be synthesized in the gut was suggested about 30 years ago, and the occurrence of it in the gut of animals was first demonstrated 20 years ago. The production of vitamins in the gut of animals has been attributed to the presence of various micro-organisms in the gut. Vitamin production in the gut is apparently particularly marked in ruminant animals, whose rumen is naturally rich in micro-organisms including cellulose-splitting bacteria. During recent years, opportunity for further study of bacterial activity in the gut and vitamin production has been afforded by the discovery of the action of certain poorly absorbed sulphonamides, such as sulphaguanidine and succinyl sulphathiazole, in reducing or temporarily eliminating bacterial activity in the gut. The action of these sulphonamides in animals has been followed by a marked fall in the excretion of various vitamins, and this is attributed to interference with bacterial activity producing them. Practically all the known fractions of vitamin B have been shown to be synthesized in the gut of animals,