relationship between vitamin d level and dna fragmentation index of sperm in men referred to omid infertility center in hamadan-iran: a cross-sectional study

Objective: unfortunately, the prevalence of infertility in iran and the world is increasing. there is limited research on the relationship between vitamin d and dna fragmentation index (dfi). dfi is a measure of dna damage in sperm cells and is used to evaluate male fertility. some studies suggest that vitamin d may play a role in sperm health and fertility.materials and methods: in this cross-sectional study, 789 eligible men referred to the omid infertility clinic in hamadan-iran in 2021-2023. serum levels of vitamin d, dfi, spermogram indexes and demographic characteristics (occupation, age, and body mass index) were collected by face-to-face interview and records review in case files. data were analyzed with spss version 27 software.results: there is no significant relationship between dfi and vitamin d before and after removing the effect of confounding variables. clearly, increasing age has been associated with increasing (dfi 95% cl: 1.06-3.03; p<0.05) odds ratio (or) = 1.79. the relationship between the increase in dfi and the decrease in normal sperm morphology (95% ci: 1.43-4.20; p<0.01) or = 2.45 and the decrease in the progressive motility of sperm was seen (95% cl: 1.66-4.87; p<0.05) or= 2.85 and also. the relationship between dfi and the decrease in sperm count after removing the effect confounding variables were observed (95%cl: 1.06-8.38; p<0.05) or=2.98.conclusion: no correlation between dfi and vitamin d serum level was found. however, a clear association was observed between increased dfi and advanced age, reduced progressive motility, abnormal sperm morphology, and decreased sperm count.