In vitro Vitamin D Treatment Enhances Sperm Motility and Capacitation of Fertile and Infertile Men.

Background: Male infertility is associated with vitamin D deficiency, and much evidence suggests ways to correct this deficiency to restore fertility. Vitamin D supplementation in men significantly improved fertility and semen parameters. This study evaluated the effects of in vitro vitamin D treatment on various sperm function parameters, such as sperm motility and capacitation, in both fertile and infertile men. Materials and Methods: Semen samples from 20 fertile and 20 infertile men were collected and divided into control and vitamin D-treated groups. The treated samples were incubated with 1 nM vitamin D for 1 hr. Sperm motility, viability, and intracellular calcium levels were assessed. Capacitation status, mitochondrial membrane potential, and protein expression were evaluated in fertile and infertile men using immunofluorescence assays. Results and Discussion: In vitro vitamin D treatment improved sperm motility and increased sperm viability in fertile and infertile males. This leads to increased intracellular calcium release and hyperpolarization of mitochondrial membranes. The results of Chlortetracycline (CTC) and phosphotyrosine immunofluorescence tests revealed a higher capacitation status in the vitamin D-treated group. In vitro vitamin D treatment positively influenced the expression of sperm-oocyte interaction proteins. It also enhances calcium ion levels and stimulates acrosome reaction and membrane hyperpolarization, thereby enhancing sperm functionality. Conclusion: In vitro vitamin D treatment enhanced sperm motility, viability, and capacitation, suggesting its potential benefits in improving IVF outcomes. [ABSTRACT FROM AUTHOR]