Effect of low-content zinc and copper formula on infant nutrition.

The zinc (Zn) content of commercially available formula milks in Japan is less than that of breast milk obtained during the first three months of lactation, but is similar to that at five months of lactation. The copper (Cu) content of the formula milks is much lower than that of breast milk obtained during the five months. These two trace elements were measured in serum (at birth, one, three, and five months of age), hair (at birth and at five months of age) and urine (at one, three and five months of age) of twenty-one breast fed and twenty formula fed full term infants. Despite the differences in Zn and Cu intakes, these parameters were similar in these two infant groups, except for urinary Zn at one and three months of age. These were significantly higher in breast fed infants (P less than 0.005 and P less than 0.05). Weight and length increments were not different in either infant group. It appeared that normal, full term infants tolerated low-content Zn and Cu formula milks well. This observation, however, is not at variance with the FAO/WHO recommendation for prevention of Zn and Cu deficiency.