Vitamin A Utilization Studies: III. The Utilization of Vitamin a Alcohol, Vitamin A Acetate and Vitamin a Natural Esters by Humans: Two Figures

Abstract

1. Blood serum vitamin A levels were used as the criterion for determining the relative utilization of the alcohol, acetate and natural ester forms of vitamin A by 18 men and 7 women, after administration of 134,000 µg of the vitamin contained in 50 gm of margarine. 2. For the male subjects, vitamin A alcohol showed greater biological efficacy than vitamin A acetate which, in turn, was superior to the natural ester forms. Vitamin A alcohol produced a greater biological response than vitamin A acetate for the female group; however, comparison of the alcohol form with a distilled natural ester preparation showed no significant difference in utilization. 3. The addition of 300 mg of tocopherols to the vitamin A alcohol supplements had no appreciable effect on vitamin A absorption. 4. After ingestion of high dosages of the vitamin, the increased vitamin A in the blood serum was present as the ester, irrespective of the chemical form of the vitamin administered in the supplement.