Zinc nutritional status, androgens, and growth retardation.

Zinc levels were measured in hair and serum of boys with constitutional growth delay and familial short status and in several boys before and after oral administration of methyltestosterone. These results show the following: (1) zinc levels in boys beyond stage 3 of genital development are significantly higher than in stage 1 and 2; (2) there is a linear relationship between zinc levels and serum testosterone concentration (up to 250 ng/dL); and (3) methyltestosterone administration raised the zinc concentration in serum and hair, especially in boys with constitutional growth delay. Therefore, increased endogenous production or exogenous supply of testosterone are associated with increased zinc levels. We speculate that the relative testosterone deficiency and hypogonadotropism seen in constitutional growth delay may result in decreased zinc levels, which in turn could cause a further delay in the appearance of secondary sexual characteristics and greater growth retardation.