In previous publications,1,2 we have discussed the need for precise knowledge of amino acid requirements and the methods of evaluating them. The present report deals with the evaluation of the valine requirement of the infant, and the technique employed has been that used in all our recent studies, namely, the use of a basal diet, the nitrogen moiety of which was supplied by a mixture of 18 l-amino acids * in the proportions found in breast milk. The intake of the amino acid under study was varied to determine the minimal quantity required to permit normal weight gain and nitrogen retention as well as the appearance of health. In each instance, as the amino acid under study was reduced it was replaced by glycine in order to keep the nitrogen intake constant.
Subjects
These studies were carried out on five normal male infants who were hospitalized for social reasons. They