Combined Effects of High-Intensity Interval Training and Vitamin D Supplementation on the Levels of Inflammatory Markers, Transforming Growth Factor Beta 1 (TGF-β1) and Tumor Necrosis Factor Alpha (TNF-α), in Young Women with Vitamin D Deficiency: A

Background and Objective: Vitamin D deficiency is highly prevalent among obese individuals, with multiple underlying mechanisms contributing to this condition. This study aimed to determine the combined effects of high-intensity interval training (HIIT) and vitamin D supplementation on the levels of inflammatory markers, transforming growth factor beta 1 (TGF-β1) and tumor necrosis factor alpha (TNF-α), in young women with vitamin D deficiency. Methods: In this clinical trial, 39 sedentary women with vitamin D deficiency were randomly assigned to three groups: A control group, a HIIT-based running group, and a combined group (training + vitamin D). The training program included 12 one-minute repetitions of running at 80% to 90% of maximum heart rate (HRmax) and one minute of active rest at 50% HRmax, performed three sessions per week. Vitamin D supplementation was used weekly at a dose of 50,000 IU. TGF-β1 and TNF-α levels were measured and compared before and after the intervention. Results: After 8 weeks of HIIT-based running, with and without vitamin D supplementation, the levels of inflammatory markers, TGF-β1 and TNF-α, showed a statistically significant decrease compared to the control group (P<0.05). The mean percentage change in TGF-β1 and TNF-α was also significantly greater in the combined group than in the training group without vitamin D supplementation (P<0.05). Conclusion: Following 8 weeks of HIIT-based running, both inflammatory markers, TGF-β1 and TNF-α decreased in the study subjects, and this reduction was more pronounced in the vitamin D-receiving group.