Vitamin A and D Potencies of Oil from Body, Liver and Intestines of Pilchard, Herring, Salmon and Tullibee

Abstract

In vitamin A (colorimetric) and vitamin D (biological) assays on representative seasonal samples of commercially produced pilchard and herring oil (from the whole fish), the vitamin D potency was found to vary inversely with the yield of oil, and the potencies of these oils with laboratory samples of tullibee oil were found to be within the range quoted for authentic cod liver oil, whereas the vitamin A potency was considerably lower than for most fish liver oils. The vitamin D of pilchard, herring, and salmon offal oil was found equally effective for rats and chickens. Vitamin D was found occluded with the stearine fraction of herring oil and was separated from it by three recrystallizations from acetone. The vitamin D potency of herring oil was found not to be related to the size of the fish.