en فیزیولوژی ورزشی Sport Physiology تحقيقي Original Paper <div><strong>Background and Objectives: </strong>Prolonged exercise can reduce physiological capacities and cause DNA damage by inducing oxidative stress and inflammatory responses. Aerobic exercise reduces the risk of cancer by activating DNA repair enzymes and reducing oxidative stress. The aim of the present study was to investigate effects of eight weeks of aerobic exercise with and without vitamin D supplementation on DNA damage.<br> &nbsp;&nbsp;&nbsp;&nbsp;<br> <strong>&nbsp;&nbsp; Methods: </strong>Forty-eight adult male rats were randomly divided into six groups: control (C), H₂O₂ (H), H₂O₂and vitamin D (HD), H₂O₂ and exercise (HE), H₂O_2,, vitamin D and exercise (HDE), and dimethyl sulfoxide. Cancer was stimulated through intraperitoneal injection of H₂O₂(2 mmol/kg). Animals in groups HE and HDE ran on treadmill for eight weeks. Concentration of 8-hydroxy-2&#39;-deoxyguanosine (8-OHdG) and O⁶-methylguanine DNA methyltransferase (MGMT) was measured by enzyme-linked immunosorbent assay. Statistical analysis of data was carried out using SPSS 22 at significance level of 0.05.<br> &nbsp;<br> <strong>&nbsp;&nbsp; Results</strong><strong>:</strong> Vitamin D supplementation significantly lowered the level of 8-OHdG expression compared to the control group (P=0.0001). The 8-OHdG expression in the exercise group was slightly lower than control group (P=0.063). Combination of exercise and vitamin D supplementation had no significant effect on expression of 8-OHdG (P=0.281). Both exercise and vitamin D supplementation significantly increased MGMT expression compared to the control group (P=0.0001 and P=0.040). However, combination of exercise and vitamin D supplementation had no significant effect on MGMT expression (P=0.326).<br> &nbsp;<br> <strong>&nbsp; Conclusion:</strong> The results showed that aerobic exercise and vitamin D supplementation can have protective effects against DNA damage, possibly by increasing antioxidant capacity and DNA repair.</div> <span dir="RTL"></span> DNA, 8-OHdG, 6-Methyl Guanine, Vitamin D, Exercise 31 37 http://mlj.goums.ac.ir/browse.php?a_code=A-10-694-2&slc_lang=en&sid=1 seyedeh tahereh haeri Tahaereh.haeri@yahoo.com 100319475328460018255 100319475328460018255 No Department of Exercise Physiology, Central Tehran Branch, mohammad ali azarbayjani mail: m_azarbayjani@iauctb.ac.ir 100319475328460018256 100319475328460018256 Yes Department of Exercise Physiology, Central Tehran Branch, I Maghsoud peeri m.peeri@iauctb.ac.ir 100319475328460018257 100319475328460018257 No Department of Exercise Physiology, Central Tehran Branch,