During the past four years, comparative studies on the vitamin content of human milk and cow's milk have been in progress in these laboratories.1 A summary of the results obtained are herewith presented for the purpose of aiding those charged with the care of infants in evaluating the two types of milk so frequently used interchangeably in infant feeding. These data, together with their discussion, may be of value in establishing a more adequate understanding of the growth-promoting and disease-protecting requirements of infants, and in explaining some of the causes and conditions of malnutrition in infants.
At present the vitamin content of foods is given in terms of the volume or weight of a given substance required to produce growth and to protect against or cure a specific vitamin deficiency disease in standard experimental animals held under carefully controlled conditions. Thus, the quantitative aspect of the vitamins can be