Amino Acid Requirements of Children: Minimal Needs of Tryptophan, Arginine and Histidine Based on Nitrogen Balance Method

Abstract

Minimal requirements for tryptophan, arginine and histidine of eleven 10- to 12-year-old boys were estimated by using the nitrogen balance method. Urinary excretion of creatine, creatinine, riboflavin and N-MNA was also measured. All children maintained a constant body weight and positive nitrogen balance without any accompanying clinical symptoms throughout the periods of arginine and histidine deprivation. With respect to tryptophan, all children maintained a positive balance at a level of 0.12 g, but some of them could not maintain a positive balance at the level of 0.06 g. The results obtained in all of our experiments with 10 amino acids in children have been summarized.