Effect of Vitamin D Supplementation on Vascular Functions and Oxidative Stress in Type 2 Diabetic Patients with Vitamin D Deficiency

BACKGROUND: Vitamin D levels are reported to have an inverse liaison with the risk of cardiovascular diseases. Hence, we aimed to evaluate the effect of Vitamin D supplementation on changes in vascular functions and oxidative stress in type 2 diabetic patients with Vitamin D deficiency. SUBJECTS AND METHODS: One hundred and three patients with type 2 diabetes attending endocrinology outpatients department in a tertiary care hospital were screened for Vitamin D deficiency. Patients with serum 25-hydroxy Vitamin D levels <20 ng/ml were considered as deficient and were administered 60,000 IU of oral Vitamin D(3) weekly for 8 weeks. In these patients, parameters of vascular functions (carotid-femoral pulse wave velocity, brachial-ankle pulse wave velocity, and arterial stiffness index) and oxidative stress (serum malondialdehyde levels and total antioxidant status) were measured at baseline and after 8 weeks of oral Vitamin D supplementation. RESULTS: Among 103 patients with type 2 diabetes, 75 (72.82%) were found to have Vitamin D deficiency. Amidst these patients, carotid-femoral pulse wave velocity (991.6 ± 161.82 vs. 899.29 ± 151.86, P < 0.001), right brachial-ankle pulse wave velocity (1446.16 ± 204.33 vs. 1350.8 ± 178.39, P < 0.001), and left brachial-ankle pulse wave velocity (1493.81 ± 219.65 vs. 1367.61 ± 220.64, P < 0.001) showed a significant reduction following Vitamin D supplementation. Further, these patients were found to have significant fall in serum malondialdehyde levels with rise in total antioxidant status ensuing Vitamin D supplementation. CONCLUSION: The present study shows that oral Vitamin D supplementation of 60,000 IU/week for 8 weeks significantly improves vascular functions and reduces oxidative stress in type 2 diabetic patients with Vitamin D deficiency.