Aim: Folic acid is a prominent intermediary in transferring the methyl groups in DNA synthesis, stability, and integrity. 

Material and methods: In this study, we divided one hundred subjects into three groups as the controls, as well as two randomly intervention groups such as first treatment (vitamin E 400 IU and selenium 200 μg per day) and second treatment (selenium 200 μg, folic acid 5 mg daily, & vitamin E 400 IU). The DNA methylation percentages, the sperm chromatin/DNA quality, and DNMTs expressions profiles were evaluated before and after each intervention using ELISA, cytochemical tests, and qRT-PCR, respectively. 

Results: Sperm parameters were considerably enhanced in comparison to the three-drug group. Moreover, sperm decondensation and fragmentation of sperm DNA in the three-drug group were significantly lower than in the two-drug group. The global methylation of sperm DNA in the three-drug group was significantly reduced compared to pre-intervention.

Conclusion: The increased global methylation has an association with the declined sperm parameters as well as chromatin integrity. The expression of DNMTs was not affected by the intervention. The utilization of folic¬ acid could ameliorate sperm quality and epigenetic features in terms of balancing the status of global methylation, increasing DNA integrity and chromatin, and also improving the sperm parameters.