Background: Vitamin D is crucial in regulating calcium and phosphorus absorption, skeletal metabolism, and immune system function. This study aimed to investigate the impact of resisted muscle exercise on vitamin D levels in obese insulin-resistant patients, assessed through blood level vitamin D tests and HOMA-IR.

Patients and Methods: Fifty-two female patients aged between 30 and 40 years, with a BMI between 30 and 39.9 kg/m2, participated in the study. They were randomly assigned to two groups: Group A received vitamin D supplements, resisted exercise, and a balanced diet, while Group B received vitamin D supplements and followed a balanced diet. Both groups were evaluated using the same methods.

Results: Both groups demonstrated significant improvements in all outcome measures compared to baseline (p < 0.05). However, Group A showed greater improvements in insulin resistance (mean difference -0.96; p = 0.001) and vitamin D levels (mean difference 7.79 ng/ml, p = 0.001) compared to Group B after the intervention.

Conclusion: Resisted exercise effectively improves insulin resistance and vitamin D levels in middle-aged women with vitamin D deficiency. The combination of exercise and vitamin D supplementation may offer greater benefits than either intervention alone.