Zinc supplementation increases growth velocity of male children and adolescents with short stature.

We assessed the effect of zinc supplementation on growth velocity in 79 children and adolescents (48 males, 38 females) with idiopathic short stature. Their height-for-age was < 5th percentile (NCHS standards) and their weight-for-age was normal. Patients were assigned randomly to a supplemented group (S) to receive Zn 10 mg/day or to a placebo (P) group, according to gender and age, and were followed-up for 12 months using a double-blind design. Weight, height, armspan, length of lower segment and plasma and hair concentrations of Zn were measured at 0, 3, 6 and 12 months. On admission and at 6 months, energy, protein, dietary fiber and zinc intakes were similar for groups S and P; mean zinc intake was < 6.5 mg/day. No differences were found in plasma zinc, hair zinc, weight, armspan or lower segment increments. Pre-adolescent males in group S had a significantly greater increase in stature compared with group P (6.2 +/- 2.1 versus 4.5 +/- 1.2 cm/year p < 0.025); z score improved from -2.42 to -2.24 in group S and from -2.63 to -2.61 in group P. For adolescent males, the difference was also significant (8.3 +/- 1.5 versus 6.2 +/- 2.1 cm/year; p < 0.025). No differences were noted in females. In Chilean male schoolchildren and adolescents with idiopathic short stature, zinc supplementation increases growth velocity over a 12-month period.