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

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.