Abstract
Vitamin A deficiency in rats and mice was induced by restricting dams and litters from parturition to a pelleted diet made mainly from white flour. Young rats usually developed clear signs of avitaminosis A within 60 days from birth. Mice were more resistant, and some survived for periods up to 150 days from birth. Retention of traces of vitamin A in the liver was no more prolonged in mice than in rats. In mice, enlargement of the prostates and seminal vesicles, and atrophy of the testes, were usually the most prominent pathological features.
In rats, timely treatment with vitamin A acid (retinoic acid) cured xerophthalmia and restored growth. Signs of deficiency reappeared soon after its administration was stopped. This procedure allows supplies of animals to be kept in good general health, but ready for the production of acute deficiency at short notice. Retinoic acid was also effective in curing deficient mice.
Incidental observations on the eyes and reproductive powers of mice or rats dosed with retinoic acid, and on the response of rats to variations in the casein contents of their diet, are recorded.