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

Abstract

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.

Serum zinc and copper concentrations in low birth weight infants during first three months of life: Correlation to birth weight and different feedings.

“…Berfenstam (1952) reported very high serum levels in 20-26 week old fetuses and Sann et al (1980) found a significant negative correlation between serum Zn level and gestational age. These observations are comparable to our findings that the serum Zn level at birth was higher in the low birth weight infants than in the full term infants measured in our laboratory previously (Higashi et al 1982). The decline of serum Zn level during the first month of life found in the present study had been reported by many investigators (Gibson and Dewolfe 1981;Higashi et al 1982) and this was probably correlated well with negative Zn balance in the newborn period (Cavell and Widdowson 1964;Dauncey et al 1977).…”

“…These observations are comparable to our findings that the serum Zn level at birth was higher in the low birth weight infants than in the full term infants measured in our laboratory previously (Higashi et al 1982). The decline of serum Zn level during the first month of life found in the present study had been reported by many investigators (Gibson and Dewolfe 1981;Higashi et al 1982) and this was probably correlated well with negative Zn balance in the newborn period (Cavell and Widdowson 1964;Dauncey et al 1977). Cavell and Widdowson (1964) showed that breast fed full term infants aged 5 to 8 days were in negative Zn balance averaging -230 ,u g/kg/day.…”

“…This fact may account for the present observation that the serum Zn level of breast fed infants was almost consistently higher than those of the other two different formula fed infants in Groups I and II, although the Zn contents of breast milk at 1 month are corresponding to those of Zn-supplemented formula. In full term infants, however, the serum Zn levels were similar regardless of such feedings (Higashi et al 1982;Matsuda et al 1984). We speculate that full term infants can tolerate, by some regulating mechanisms, a formula of low-Zn content (Matsuda et al 1984).…”

“…Feeding was started in all infants during the first two days of life with breast milk obtained from their own mothers, commercially available formula, or Zn-and Cu-supplemented formula. Zn and Cu contents of breast milk and the formulas were analyzed by the methods described previously (Higashi et al 1982). Breast milk of formula was given through a nasogastric tube (ATOM) in all infants with a low birth weight and by bottle when infants were able to suck.…”

“…Levels of Zn and Cu were measured by atomic absorption spectrophotometry (Perkin/ Elmer, Model 403) as described previously (Higashi et al 1982). The formulas supplemented with Zn and Cu, added as sulfates, were kindly supplied by Snow Brand Milk Company or Morinaga Milk Company, Tokyo.…”