Effects of High Levels of Dietary Vitamin A Acetate on Tissue Tocopherol and Some Related Analytical Observations

Abstract

The total tocopherol content of liver tissue and plasma was determined after 2-week-old vitamin A-depleted chicks had received 0.5, 5, 50, 500, and 5,000 mg of vitamin A acetate/kg of diet for 5, 10, and 20 days. The tocopherol content in the tissues was markedly depressed especially at the highest levels of vitamin A intake. The depletion of tocopherol from the tissues at the highet levels of vitamin A intake was similar to that previously encountered by feeding a vitamin E-low basal diet. Decreasing liver tocopherol values with time at a dietary level of 17.6 mg of dl, α-tocopheryl acetate/kg may be indicative of a gradually increasing tocopherol requirement of the rapidly growing chick. Florex chromatography was unsatisfactory in removing the large amounts of vitamin A in the liver. Hydrogenation of the vitamin A followed by chromatography through Florex proved to be satisfactory.