The Sulfur Amino Acid Requirement of the Infant

Abstract

The sulfur amino acid requirements of 5 normal male infants (4–11 months of age) were studied. In three infants who received no cystine supplements the nitrogen retention and body weight gains were restored to normal levels by an intake of 85 mg of L-methionine per kilogram of body weight. In two infants who received a 1% L-cystine supplement the nitrogen retention and weight change were restored to normal values by an intake of 65 mg of L-methionine per kilogram of body weight. The implications of these findings are discussed in reference to the nutritional virtues of human and cow's milk.