Estimates of Amino Acid Requirements
Estimates of Amino Acid Requirements
Estimates of Amino Acid Requirements
| Requirements, mg/kg per day, by age group | ||||
|---|---|---|---|---|
| Amino Acid | Infants, Age 3–4 mo b | Children, Age ∼2 yr c | Children, Age 10–12 yr d | Adults e |
| Histidine | 28 | ? | ? | 8–12 |
| Isoleucine | 70 | 31 | 28 | 10 |
| Leucine | 161 | 73 | 42 | 14 |
| Lysine | 103 | 64 | 44 | 12 |
| Methionine plus cystine | 58 | 27 | 22 | 13 |
| Phenylalanine plus tyrosine | 125 | 69 | 22 | 14 |
| Threonine | 87 | 37 | 28 | 7 |
| Tryptophan | 17 | 12.5 | 3.3 | 3.5 |
| Valine | 93 | 38 | 25 | 10 |
| Total without histidine | 714 | 352 | 214 | 84 |
- a
-
From WHO (1985).
- b
-
Based on amounts of amino acids in human milk or cow's milk formulas fed at levels that supported good growth. Data from Fomon and Filer (1967).
- c
-
Based on achievement of nitrogen balance sufficient to support adequate lean tissue gain (16 mg N/kg per day). Data from Pineda et al. (1981).
- d
-
Based on upper range of requirement for positive nitrogen balance. Recalculated by Williams et al. (1974) from data of Nakagawa et al. (1964).
- e
-
Based on highest estimate of requirement to achieve nitrogen balance. Data from several investigators (reviewed in FAO/WHO, 1973).
