The effect of zinc supplementation on linear growth in short stature school-aged children in Qazvin

Abstract Background: Physical growth retardation is an early and prominent feature of zinc deficiency. Objective: To determine the effect of zinc supplementation on linear growth of school children with short stature in Qazvin during 2004-2005. Methods: The study was designed as a double-blind randomized clinical trial during a 5-month period. Anthropometric data were collected at 0, 1, 2, 3, 4, and 5 months. Measurements included plasma zinc concentration, height, weight, nutrition state. Subjects were 30 short stature female students (<3rd percentile) aged 10-11 years. Children were randomly divided into two groups, one with zinc supplementation (15mg/day ZnSo4) and the other with placebo. As control group, 15 healthy children with normal growth were included. Findings: The prevalence of short stature in children was 7.1% (52 from 725 children). The mean age was 10.5±0.5 years. After supplementation, zinc group showed a higher serum zinc concentration (89.5±12.99 vs. 81.1±9.04 µg/dl, p=0.009) compared to the placebo group (72.66±7.82 vs. 86.13±17.8 µg/dl) with one child found to have serum zinc concentration of less than 70 µg/dl. The linear growth rose at 3, 4, and 5 months following supplementation. The height velocity was significantly increased in zinc group (3.22±0.9cm) comparing with placebo (2.33±0.7cm) and control (3.02 ±1.59cm) groups (p=0.004). The weight increase was statistically significant only at the end of 5 months compared to the beginning of study. Conclusion: Zinc supplementation caused an increase in growth velocity and serum zinc concentration. Regarding the notable prevalence of zinc deficiency in female students during the adolescence growth spurt, zinc supplementation is recommended.