Effect of zinc supplementation on growth and body composition in children with sickle cell disease

BACKGROUND: Poor growth and delayed maturation in children with sickle cell disease (SCD) may be due, in part, to mild zinc deficiency. OBJECTIVE: The objective was to determine the effects of zinc supplementation on growth and body composition in children with SCD. DESIGN: Forty-two prepubertal children (20 girls and 22 boys) aged 4-10 y with SCD-SS were randomly assigned to receive 10 mg elemental Zn/d in cherry syrup (zinc group) or cherry syrup alone (control group). The 2 groups were stratified by sex and initial height status. Dietary intakes were evaluated and anthropometric, high-precision knee-height, and plasma zinc measurements were made at baseline and at 3, 6, and 12 mo. Body composition was determined every 6 mo with dual-energy X-ray absorptiometry, and z scores for anthropometric variables were computed from national reference data. Longitudinal-mixed-effects analysis was used to test for differences between the groups over the 12-mo observation period. RESULTS: Thirty-eight children completed the study. No significant differences were observed at baseline. After 12 mo, the zinc group had significantly greater mean (+/- SE) increases in height (0.66 +/- 0.29 cm/y), sitting height (0.97 +/- 0.40 cm/y), knee height (3.8 +/- 1.2 mm/y), and arm circumference z scores (0.27 +/- 0.12 cm/y). Height-for-age and weight-for-age z scores decreased significantly by 0.11 +/- 0.04 and 0.13 +/- 0.05, respectively, in the control group but did not change significantly in the zinc group. CONCLUSIONS: Prepubertal children with SCD-SS may have zinc deficiency and may benefit from zinc supplementation to improve linear growth and weight gain.