Does Zinc Improve Children's Growth?

OAKLAND, Calif.--Zinc deficiency in prepubescent children with sickle cell disease may lead to stalled growth; however, researchers from the Children's Hospital of Philadelphia and colleagues discovered that zinc supplementation can enhance linear growth and weight gain in these children. The research, published in the February 2002 issue of the American Journal of Clinical Nutrition (75, 2:300-07, 2002) (www.ajcn.org), was conducted with 42 prepubertal children with sickle cell disease who were randomly assigned to receive 10 mg/d of elemental zinc or placebo. Body composition was determined at six and 12 months. There were no significant differences between the children at baseline.

Of the original 42 children, 38 completed the study. After 12 months, the zinc group demonstrated a significantly greater mean increase in height, sitting height, knee height and arm circumference than the control group. Height and weight, as compared to age group, decreased significantly in the control group, but were not affected in the zinc group. Researchers concluded that adding zinc to the diets of sickle cell diseased children can enhance height and weight gain.

While these results are promising, a study published in the same journal last month (75, 1:87-91, 2002) indicated that short-term supplementation with zinc and vitamin A had no effect on the growth of undernourished children. Researchers from the International Centre for Diarrhoeal Disease Research in Dhaka, Bangladesh, studied the possibility that adding zinc to a vitamin A regimen might enhance growth in undernourished children. However, of 653 children in the trial--randomly assigned to receive 20 mg/d of zinc for 14 days, 60,000 retinol equivalents of vitamin A on day 14, zinc plus vitamin A, or placebo--none demonstrated significant weight or height changes over the six-month study period.