Effects of Vitamin A Malnutriture on Resistance to Stress.

Abstract

The avg. survival time of rats depleted of vit. A was 1.9 days at 2[degree] C and 19.3 days under standard laboratory conditions (23[degree] C). Adjustment to low temp. (as judged by % surviving an exptl. period of 30 days) was significantly increased in animals fed an avg. daily intake of25 U.S.P. units of vit. A, but a minimal intake of approx. 5 U.S.P. units of vit. A daily was required for optimal adjustment to cold. A direct correlation was observed between the vit. A content of the diet and resistance to X-irradiation. All rats admd. an avg. intake of 2.5 U.S.P. units of vit. A daily succumbed following a single exposure of 750 r X-irradiation; 90% of the rats receiving a daily intake of 50 U.S.P. units of vit. A and exposed to a similar dose of X-irradiation survived. An avg. daily intake of 10 U.S.P. units of vit. A was inadequate for optimal resistance to X-irradiation, although this level of vit. A was adequate under standard laboratory conditions for optimal growth.