The effect of vitamin D in vitro supplementation on sperm deoxyribonucleic acid fragmentation.

Objective: This study aimed to identify the direct effect of vitamin D on sperm DNA integrity after swim-up preparation.

Materials and methods: Normozoospermia samples were gathered from 12 men and assessed for their baseline characteristics, including DNA Fragmentation Index (DFI). Each sample was then prepared using the swim-up method. Half of the samples were incubated with vitamin D, while the other half were incubated with a standard sperm-washing medium.

Results: Vitamin D significantly reduced the DFI compared to the baseline (5.5 ± 3.4% versus 17.6 ± 4.2%; p < 0.001) and the swim-up-only group (5.5 ± 3.4% versus 12.0 ± 4.2%; p < 0.001). Microscopic examination reflected these results, showing a reduction in the number of small halos and no halos with an increased appearance of large to medium-sized halos.

Conclusions: These results suggest that vitamin D incubation is valuable in protecting sperm from DNA damage that develops during sperm preparation. However, additional investigation is warranted to explore other preparation methods and to elucidate the underlying mechanisms.