RT Journal A1 SNYDERMAN SE, NORTON PM, FOWLER DI, HOLT L, Jr., Hasselmeyer E, Boyer A T1 The essential amino acid requirements of infants: Lysine JF A.M.A. Journal of Diseases of Children JO A.M.A. Journal of Diseases of Children YR 1959 FD February 1 VO 97 IS 2 SP 175 OP 185 DO 10.1001/archpedi.1959.02070010177004 UL http://dx.doi.org/10.1001/archpedi.1959.02070010177004 AB Acurate knowledge of essential nutrients is a sine qua non of good nutrition. Such information is needed for the prevention and repair of dietary deficiencies arising from food shortages and also in situations where the capacity to handle food is limited by disease states. Evaluation of the requirements for essential amino acids has been peculiarly difficult, since this involves the construction of a diet in which the quantity of a single amino acid can be varied at will. The problem has been approached in several ways:Use has been made of natural proteins deficient in one or another amino acid. This method has very limited applicability, for nature has been singularly unobliging in providing a variety of such proteins.Chemically degraded proteins or protein hydrolysates have been used. A number of procedures can be used to destroy one or more amino acids, which can then be replaced in