Cxix. Hypervitaminosis and Vitamin

THE object of this paper is to record a continuation of experiments in which the existence is demonstrated of a "balance" between the vitamin B complex on the one hand and vitamins A and D of cod-liver oil on the other. Only two previous communications bearing directly on this subject have appeared in the literature, so far as we are aware. In the first place, Hopkins [1923] mentioned that he had found that a moderate excess of cod-liver oil was often injurious to the rat unless "balanced" by an increased marmite (vitamin B) allowance'. Secondly, Harris and Moore [1928] have published details of investigations in which it was shown that the substitution of cod-liver oil for arachis oil in rations containing various restricted allowances of vitamin B resulted in a further lowering of growth rates2. In these experiments comparatively large quantities of cod-liver oil (15 % of the diet) were administered, and, since there are many substances in codliver oil of whose chemical nature and properties little is known, there was no necessity to assume that the ill-effects observed were necessarily due to vitamins. (Our conclusions here were contrasted with those concerning the specific hypervitaminosis D resulting from excessive irradiated ergosterol.) It was therefore of interest to repeat our experiments using vitamin concentrates instead of cod-liver oil so as to eliminate at least the materials present in the saponifiable fraction of the oil.