Does Our Dietary Require Vitamin a Supplement?

In spite of great and rapid advances in knowledge concerning the rôle of the vitamins, there is a striking difference of opinion as to the requirement of these essential factors. Some believe that, under normal conditions, the peoples of the United States and those living in countries similarly situated economically need not be concerned as to the fulfilment of their vitamin requirements. Others are of quite the contrary opinion. This divergence has centered mainly on vitamin A, variously termed the fat-soluble, growth or anti-infective vitamin. Although the necessity of including this vitamin in the dietary of both animals and man is universally conceded, especially for the young, there is nonagreement as to whether the bodily needs are being adequately met and, accordingly, whether there is danger of a deficiency of vitamin A leading to latent forms of nutritional disturbances. For several years we have been actively interested in this problem.