Effects of vitamin E and vitamin C on male infertility: a meta-analysis

PurposeThe efficacy of the antioxidants vitamin E (VitE) and vitamin C (VitC) on male infertility is uncertain. Therefore, this research systematically assessed the influences of VitE and VitC on male infertility.MethodsWe did a meta-analysis of randomized controlled trials (RCTs) to analyze semen parameters, pregnancy rate, and adverse effects (AEs) between VitE and VitC groups and control groups by searching Cochrane Library, Excerpta Medica Database (Embase), PubMed, China Biology Medicine disc (CBMdisc), and Web of Science up to June 2020.ResultsWe screened 11 studies (832 patients) that met the inclusion criteria. The evidence quality ranged from moderate to low. The pregnancy rate was obviously better in the VitE group than in the control group (relative risk (RR) 1.86, 95% confidence interval (CI) 1.02–3.41). Compared with the control group, VitE and VitC significantly improved progressive motility (standardized mean difference (SMD) 0.38, 95% CI 0.22–0.55), sperm concentration (SMD 0.21, 95% CI 0.09–0.34), sperm morphology (SMD 0.32, 95% CI 0.09–0.55), and total sperm number (SMD 0.28, 95% CI 0.12–0.43) without AEs.ConclusionThis study suggests that VitC and VitE can improve the spousal pregnancy rate and semen parameters in infertile men without AEs.