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

Objective: To review possible causes for male factor subfertility with emph asis 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 li terature. Both environmental and genetic factors could play a role. However , the pathogenesis of male factor infertility is poorly understood, includi ng the role of specific micronutrients such as zinc and folate. Both zinc a nd folate are involved in the synthesis of DNA and RNA. Despite the fact th at zinc deficiency leads to several clinical symptoms such as decreased spe rmatogenesis 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 nutrition al deficiencies is in principle amenable to curative and/or preventive acti on by supplementation, emphasis should be put on studies on the effect of s pecific nutrients on male fertility. (C) 2000 by American Society for Repro ductive Medicine.