THE PHARMACOLOGY AND THERAPEUTICS OF VITAMIN A

Abstract

Treatment with vitamin A is indicated in disorders clearly due to deficiency of vitamin A in the diet. These disorders include nutritional night blindness, xerophthalmia, keratomalacia and a definite kind of follicular keratosis of the skin. The use of vitamin A in the prophylaxis of these disorders is also well established. It is appropriate to discuss these well defined uses of vitamin A before undertaking an analysis of the other uses proposed for vitamin A. Tests for loss of adaptation to dim light have been introduced recently as a measure of deficiency of vitamin A. These tests are considered in the section of this review dealing with night blindness. Treatment with vitamin A has been suggested in conditions obviously not due to deficiency, for example, in hyperthyroidism, because experiments with animals demonstrate an antagonism between vitamin A and thyroxine. Vitamin A has also been used for the local treatment of