Meta-analysis of the relevance between sperm parameters and serum vitamin D levels in infertile men

Abstract

To systematically estimate the relevance between sperm parameters and serum vitamin D levels and the subsequent reproductive outcomes in men. PubMed, Web of Science and other databases were searched for studies that examined a possible correlation between serum vitamin D levels and sperm parameters and reproductive outcomes. The documents were screened according to the corresponding inclusion and exclusion criteria. Selection criteria included all published randomised and controlled trials and non-randomised studies that focus on vitamin D and the reproductive function of men The patients were classified into observation/intervention and control groups, the intervention group was given vitamin D supplementation and the control group was not. The meta-analysis was conducted using Stata 16.0 software. A meta-analysis of 11 clinical studies that enrolled a total of 1356 patients, revealed that the clinical pregnancy rate in the observation group was no statistically different in the control group. A meta-analysis of 8 studies demonstrated that there was no statistically difference in sperm concentration between the experimental group and the control group. A meta-analysis of 8 studies found that sperm progressive motility in the experimental group was greater than that in the control group by using a random-effects model. The mean concentration of vitamin D was significantly lower in the control group. Appropriate vitamin D supplement intervention in infertile men improves sperm progressive motility. Interpretation of these results should be done with caution due to the significant heterogeneity of the included studies. Furthermore, Well-conducted prospective cohort studies are needed to better explain the relationship between vitamin D and sperm parameters in infertile men.