Non-Identity of Gray Hair Produced by Mineral Deficiency and Vitamin Deficiency

Abstract

The recent recognition of a specific organic food factor 1 2 necessary for the maintenance of the black fur of black or piebald rats has raised the question as to whether the phenomenon of graying noted by older workers 3 4 5 6 particularly in rats on an exclusive milk diet is due to this cause or is due to a specific mineral deficiency. Jukes and Richardson 7 have pointed out that milk is not a good source of filtrate fraction vitamins.

The black fur of young piebald rats fed an exclusive diet of either powdered whole milk or of fresh certified milk rapidly and uniformly became gray. Addition of a supplement of 0.25 mg of iron, 0.05 mg of copper and 0.05 mg of manganese cured the grayness if it had developed or prevented any change in the color of the fur of rats which were fed milk with the above mineral supplements from the time of weaning. Attempts to ascertain which of the 3 metals is responsible have not at present yielded entirely conclusive results.

Rats developing a nutritional anemia show a marked diminution of appetite and the possibility exists that the graying of rats may be due to a diminished intake of vitamin accompanying the reduced intake of the vitamin-poor milk. This has been disproven since in 2 groups of rats fed isocaloric amounts of milk, those supplemented with iron, copper and manganese did not develop grayness whereas those fed milk alone became quite gray. It has also been found that rats that have developed grayness will become black when supplement-ed with the above minerals whereas the isocaloric controls without minerals remain gray. Rats, following the production of gray hair by a milk diet, when supplemented with a rice bran extract∗ rich in the factors of the B complex very slowly regained their black color. However, control rats fed equal quantities of the ashed rice bran extract likewise slowly became black.