Effect of supplementation of preterm formula with long chain polyunsaturated Fatty acids on mineral balance in preterm infants

BACKGROUND: Incorporation of long chain polyunsaturated fatty acids (LCP) into formulas may interfere with mineral metabolism. We investigate mineral balance in preterm infants who were fed a formula with LCP. METHODS: Infants were randomized in a double-blind manner, 20 infants in each group, to receive a formula with LCP (F+LCP) or without LCP (F) for 30 days. Plasma levels (at the beginning and after 30 days) and nutritional balance (after 1 week) for Ca, P, Mg, Zn, and Cu were obtained for all infants. RESULTS: Groups were similar regarding birth weight, gestational age, weight, and corrected age at study start. During the 30-day study period, the groups had comparable milk intake and reached similar and satisfactory weight gains and longitudinal growth. Within each group, there was no change in plasma mineral concentrations over the course of the study, and there were no differences at each time point between groups. All values were within the normal range for age. No differences in mineral balance were detected between the F and F+LCP groups, with both groups demonstrating comparable intake, net retention, and fecal losses of each mineral. CONCLUSIONS: Adding a content of LCP blend similar to that of human milk to a preterm formula caused no disturbance in Ca, P, Mg, Zn, or Cu nutritional balance.