Background: This study aimed to investigate the effect of 8 weeks of aerobic exercise combined with vitamin D supplementation on nitric oxide (NO) and endothelin-1 (ET-1) in patients with hypertension. Materials and Methods: In this quasi-experimental study, 40 eligible men and women with hypertension were randomly divided into four groups: supplement, placebo + exercise, supplement + exercise, and control. The training program included eight weeks of aerobic exercise running on a treadmill for 8 weeks, 3 sessions per week. The supplementation program included the intake of vitamin D supplements (2000 IU) daily in a double-blind manner. The placebo program was the intake of a capsule containing maltodextrin. Blood sampling was taken to evaluate biochemical variables 48 hours before and after the intervention in a fasting state. Results: After 8 weeks of aerobic exercise plus vitamin D supplementation, there was no significant effect on body mass index, NO, triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, vitamin D level, and weight (P>0.05). However, the ET-1 level and systolic blood pressure were changed significantly in the supplement, supplement + exercise, and exercise + placebo groups compared to the control group (P<0.05). Conclusion: Eight weeks of vitamin D supplementation combined with aerobic exercise can reduce ET-1 level and improves systolic blood pressure in people with hypertension.
