Greying of Fur and Other Disturbances in Several Species Due to a Vitamin Deficiency

Abstract

Young black or hooded rats were fed a basal diet adequate except with respect to the B vitamins and supplemented by thiamin chloride, riboflavin and a wheat germ preparation rich in vitamin B₆. The animals grew fairly well but within 6 to 10 weeks developed a greying of the fur, usually in bilateral patterns. Certain skin eruptions and in some cases persistent large skin ulcers appeared in many of the rats subsisting on this diet for several months. Filtrates from fuller's earth-treated extracts of rice bran, yeast, liver, crude cane molasses and alfalfa in every case cured these symptoms but restored normal growth in varying degrees. Two filtrate factors appear to be involved, termed for convenience the anti-grey factor and the rat-growth filtrate factor. Injection of commercial adrenal cortex and thyroid extracts cured the greying slowly but did not restore growth. Histological study of adrenal glands, thyroids, skin and testes of these and similar rats deficient in vitamin B₆ or riboflavin showed that serious damage occurs in these tissues in the grey rats without corresponding changes in non-grey rats. Lactation failed nearly completely in all rats placed on the filtrate factor-deficient diet on either the day of mating or the day of littering. One guinea pig and eight young dogs have shown greying of the fur when subsisting on this deficient diet. The growth of the dogs was subnormal but the animals have survived for several months in spite of progressive greying of the hair, occasional diarrhea and poor appetite. Two young silver foxes were likewise affected. The possible dependence of cortical adrenal and other gland function upon one of the members of the B complex and the relation of senescent changes to this deficiency are suggested.