Serum zinc concentration in exclusively breast-fed infants and in infants fed an adapted formula.

Serum zinc concentrations have been determined in 28 healthy full-term Italian infants of both sexes at birth, as well as at 3 and at 5 months of age. Fourteen exclusively breast-fed infants who served as a control group were compared with 14 infants fed a cow's milk based adapted infant formula. No significant differences in serum zinc concentration between the breast-fed and the bottle-fed group became apparent during the study. The results of this study suggest a similar zinc nutriture in both groups. The availability of zinc from the adapted infant formula was not significantly different from that of human milk. These findings may be explained by the composition of the adapted formula tested, e.g. by a protein composition fairly close to that of human milk, by the presence of zinc derived from the natural ingredients only, by the low Fe/Zn ratio and by the elevated citrate content.