Effects of zinc supplementation on 1- to 5-year old children

To assess the impact of zinc supplementation on nutritional and biochemical parameters among children aged 12 to 59 months.

A blinded randomized clinical trial was carried out with 58 children aged 12 to 59 months included in the Programa Governamental de Combate a Carências Nutricionais (National Child Nutritional Program), which provided them with 2 kg of iron-fortified milk. The supplementation group (n = 28) received 10 mg/day of zinc sulfate for four months, and the control group (n = 30) received placebo. The following parameters were used to assess the nutritional status: weight-for-height and height-for-age expressed as z scores, according to National Center for Health Statistics (NCHS) standards, biochemical measurements of serum iron and serum zinc, and hemoglobin and hematocrit levels.

Zinc supplementation did not have a remarkable influence on anthropometric parameters. Baseline serum zinc levels were low in both groups. After supplementation, variations in mean hemoglobin (p = 0.002), hematocrit (p = 0.001), serum zinc (p = 0.023), and serum iron (p = 0.013) levels significantly increased in the zinc supplementation group.

Zinc supplementation improved hemoglobin response and normalized serum zinc concentration. The results show the importance of establishing policies for nutritional care that can tackle zinc deficiency as well.