Zinc and testosterone: the direct line most men ignore
Zinc is one of the few nutrients with a direct, documented relationship to testosterone synthesis. A 1996 study published in Nutrition (Prasad et al.) found that zinc restriction in healthy men caused testosterone levels to fall by nearly 75% over 20 weeks, and that supplementation in zinc-deficient older men nearly doubled their testosterone. The mechanism is straightforward: zinc is required for the enzyme that converts androstenedione to testosterone in the Leydig cells of the testes.
