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Background & objectives: exposure to lead has a wide range side effects on fertility. Vitamin D is one of the most important vitamins required for the body. This study was conducted to determine the effect of vitamin D on spermatogenesis in male rats treated with lead nitrate.
Methods: In this experimental study, 25 adult male Wistar rats (250-300 gr) were randomly divided into 5 groups (n=5). Control group without any treatment, the group receiving lead by gavage and experimental groups receiving lead plus vitamin D at doses of 25, 50 and 75 mg/kg body weight by gavage  for 28 days. At the end of the study, after anesthetizing the rats, blood samples were collected directly from heart and serum levels of testosterone hormone, Follicle-stimulating Hormone (FSH) andLuteinizing Hormone (LH) were measured. Histological studies were performed to count the spermatocyte and examine the diameter of the seminal tube. Data were analyzed by SPSS software using one-way ANOVA, at significance level of p>0.05.
Results: Compared to the control group,  the mean serum testosterone level in the lead group significantly decreased (p<0.001) and the mean LH and FSH serum levels significantly increased (p<0.001) . Also, spermatocytes and seminiferous tubule diameter significantly decreased (p<0.001). Vitamin D consumption reduced the effects of lead intake, and  this effectiveness was completely dose-dependent.
Conclusion: Our data showed that vitamin D has a significant effect on serum testosterone levels and gonadotropins.