Effect of Zinc Supplementation on Growth of Low Birth Weight Infants Aged 1-6 Mo in Ardabil, Iran

Abstract

To assess the effect of zinc supplementation on growth of low birth weight (LBW) infants aged 1-6 mo. LBW infants were enrolled at birth and randomly assigned to receive 5 mg elemental Zn per day (n = 45) or placebo (n = 45) until 6 mo of age. They were followed monthly for information on compliance; anthropometric measurements were performed monthly. After randomization, 5 infants from zinc group and 9 from placebo group were excluded. At 6 mo of age, significantly greater weight gains were observed in the zinc than in the placebo group (4995 +/- 741g in zinc group vs. 3896 +/- 865 g in placebo group, p=0.036). Length gain during the study period improved in zinc group (16.9 +/- 8.2 cm vs. 15.1 +/- 4.1 cm, p=0.039); after zinc supplementation head circumference were increased (8.7 +/- 1.4 cm vs. 7.4 +/- 1.5 cm p < 0.001). In male infants, total weight gain and height and head circumference gain were higher in the zinc than in the placebo group. However, only head circumference change was statistically significant. A similar trend was observed among female infants, but these differences were not statistically significant. There was no significant relation between breast-feeding status and the main outcome variables. Infants in the present study showed improvements in growth rate, but more studies are required in this field to confirm this fact.