BACKGROUND: Despite the limited evidence about the effect of micronutrient supplementation on the semen quality, many micronutrient supplements have been used to improve male fertility. Approximately, 40%-50% of male infertility cases in general and up to 80% in men with idiopathic infertility cases are caused by oxidative stress and decreased level of seminal total antioxidant capacity.
OBJECTIVE: To investigate the beneficial effects of micronutrient supplementation on sperm concentration, motility and morphology.
METHODS: A Pub Med, Google Scholar, Embase data, web of Science and Cochrane Library database extensive research of the randomized controlled studies utilizing micronutrient vitamins and supplements was performed.
RESULTS: The existent international literature is rather heterogeneous and a definitive is difficult to be drawn. Several micronutrients have beneficial effects on sperm parameters. Rational use of micronutrients might be helpful for infertile patients.
CONCLUSION: Further randomized, controlled clinical trials are required to elucidate the efficacy and safety of micronutrients and propose proper protocols for their use. A well-rounded, balanced diet is more preferable than the widespread use of micronutrient supplements beyond the recommended doses. Future studies should concern the pregnancy rate as a primary outcome in their designs. Further research should be done to determine the appropriate antioxidant compounds, the duration of the treatment, as well as a certain dose of antioxidants in clinical practices. The pre-treatment evaluation of the seminal oxidative status is also an important parameter to proceed with micronutrient supplementation without the risk of reductive stress. Under these conditions, supplements could support the quality of sperm and help to alleviate male infertility.