Vitamin A in Relation to Growth and to Subsequent Susceptibility to Infection. ∗

Abstract

Previous investigations have repeatedly shown that graded responses in rate of growth may be obtained from the feeding of quantitatively graded allowances of either vitamin A or vitamin B, in each case as supplement to a basal diet adequate in all other respects. And in the case of vitamin B it has been shown, first by Osborne and Mendel 1 and later in a different way by Sherman and MacArthur, 2 that the larger the experimental animal the greater the amount of vitamin needed to maintain a given rate of growth, or the less the rate of growth resulting from the feeding of a fixed limited allowance of the vitamin. This is now found to be true of vitamin A also, larger experimental animals, of a given age and sex, growing more slowly upon a fixed allowance of this vitamin, the allowance in all of these cases being less than would have sufficed to support a fully normal rate of growth.

The bearing of this finding upon the accuracy of the quantitative determination of vitamin A by means of the feeding method is being discussed elsewhere. The purpose of the present communication is rather to invite consideration of the bearing of these and some related observations upon the nutritional rôle of vitamin A in relation to growth and health, with special reference to the importance of this factor in the food of children.

Thus the facts now demonstrated upon experimental animals (albino rats) that the vitamin A requirement increases both with size of body and with rate of growth will mean in the feeding of children that the large child needs a liberal allowance of this vitamin because of his size and the small child needs a liberal allowance to induce and support a more rapid rate of growth.