Zinc supplementation of infant formula.

The effect of zinc supplementation of infant formula on zinc nutrition and growth of healthy infants was studied longitudinally from birth to age 12 mo. The zinc-supplemented group (n = 16) received the same formula as the unsupplemented group (n = 16) except for the addition of 61 mumol (4 mg) Zn/L as sulfate. After age 2 mo in the breast-fed and unsupplemented groups the mean serum zinc concentration remained stable at approximately 9.9 mumol/L. The zinc supplement increased the mean serum zinc concentration to 13.0 mumol/L by age 6 mo. With increasing intake of solid foods, the concentration fell by age 9 mo to the same concentration as in the other groups. The supplement did not increase the velocity of weight or length growth. In their growth the unsupplemented infants were not inferior to the breast-fed or zinc-supplemented infants.