Male factor subfertility: possible causes and the impact of nutritional factors

Objective: To review possible causes for male factor subfertility with emphasis on nutritional factors such as zinc and folate. Design: A literature search was performed on MEDLINE and via bibliographies of published works. Result(s): Many causes for male factor subfertility axe described in the literature. Both environmental and genetic factors could play a role. However, the pathogenesis of male factor infertility is poorly understood, including the role of specific micronutrients such as zinc and folate. Both zinc and folate are involved in the synthesis of DNA and RNA. Despite the fact that zinc deficiency leads to several clinical symptoms such as decreased spermatogenesis and impaired male fertility, the exact pathophysiology has not been clarified. Conclusion(s): Because most causes of male factor subfertility are unknown, more research is needed. Because male factor subfertility due to nutritional deficiencies is in principle amenable to curative and/or preventive action by supplementation, emphasis should be put on studies on the effect of specific nutrients on male fertility. (C) 2000 by American Society for Reproductive Medicine.