ZINC AND COPPER IN INFANTS FED BREAST-MILK OR DIFFERENT FORMULA

In 129 term infants at birth and at the age of 4 months, zinc and copp er concentrations of plasma and urine were determined by graphite furn ace atomic absorption spectrephotometry and the values correlated to o ther biochemical parameters and somatic data. Of the infants, 49 were exclusively breast-fed, 44 fed with various commercially available cow 's milk formula, 35 fed with a hypoallergenic formula (cows's milk whe y hydrolysate, commercially available, supplemented with zinc and copp er). Plasma zinc values declined from birth to the age of 4 months in all three groups (P < 0.001). In formula fed children, 4 months old, t he values (11.1 +/- 1.7 mu mol Zn/l) were significantly lower than in breast-fed (12.2 +/- 1.7 mu mol Zn/l; P = 0.004) or babies on hypo-all ergenic formula (12.4 +/- 1.6 mu mol Zn/l; P = 0.0015). In accordance with the literature plasma copper and caeruloplasmin values increased significantly within the first 4 months of life, the plasma levels wer e similar in either feeding group, only urinary copper excretion was h igher in male infants on hypoallergenic formula (P < 0.03) at the age of 4 months. There were no correlations between zinc or copper values and alkaline phosphatase. In infants on hypo-allergenic formula there was a negative correlation between plasma zinc and weight or height in crements. Despite different zinc and copper supply, presumedly differe nt bioavailability, and different plasma zinc values, all infants thri ved and weight and length increments were similar in each group.