Linear growth and zinc supplementation in children with short stature

Physical growth retardation is an early and prominent feature of zinc deficiency, but the effect of zinc supplementation in children is still not completely clear. This study investigated the impact of zinc supplementation on linear growth, growth velocity, IGF-I levels, and skeletal maturation of short children during and after mineral supplementation. The study was designed as a double-blind, randomized, controlled trial of zinc supplementation during a 6-month period, with a subsequent 6-month follow-up. Anthropometric data were collected at 0, 6, and 12 months. Measurements included plasma Zn, IGF-I, height, weight, triceps skinfold thickness, and body mass index. Eighteen healthy pre-pubertal short children (z-score -2.0) 7 to 10 years old with normal GH and IGF-I levels were randomized to two groups, one with zinc supplementation (5 mg/kg/d of ZnSO4) and the other with placebo. In the first 6 months, only height velocity increased significantly, 5.99+/-0.80 cm/yr vs 5.05+/-0.85 cm/yr (p=0.03). After 12 months, height velocity returned to the initial values, 3.92+/-0.59 cm/yr vs 4.19+/-1.08 cm/yr (p=0.29). This study indicates that zinc supplementation increased growth velocity, but these effects did not persist after supplementation was discontinued.