Further studies on the absorption of vitamin A

Abstract

A circular paper-chromatographic procedure for the separation of higher fatty acid esters of vitamin A, with silicone-impregnated paper and a solvent system of methanol-butanol-water (85: 10:5, by vol.), is described. Rats raised on a vitamin-A-low diet and starved for 24 hr. were dosed with vitamin A alcohol in the carriers Tweens 20, 40 and 60, groundnut oil, sesame oil, coconut oil or safflower oil; the vitamin A ester fractions of the contents, mucosae and muscles of the small intestine, and of blood and liver, were analysed by the above method 2-3 hr. after the dose. After the feeding of colloidal vitamin A, mostly vitamin A palmitate was found in the contents, mucosae and muscles of the small intestine, and in the blood and liver, of rats. The types of the esters of the contents and mucosae in all other cases were governed by the fatty acids of the carrier. No such relationship was found for the ester composition of intestinal muscles and blood, which contained almost entirely the palmitic acid ester. The liver, under all conditions studied, stored exclusively the palmitate.