Objective: Vitamin D deficiency is associated with an increased risk of type two diabetes mellitus (T2DM) and cardiovascular disease reduced through Vitamin D3 supplementation. However to the best of our knowledge, no research has determined the effect of vitamin D3 supplementation in conjunction with existing pharmacological and non-pharmacological approaches to the DMT2 population. Hence, the aim of this study was to determine the effect of vitamin D3 supplementation in a cohort of Saudi DMT2 population on different oral hypoglycemic agents and compare them with a non-DMT2 control.
Methods: A total of 499 randomly selected DMT2 subjects divided into eight groups based on their existing diabetes management (non-DMT2 control =151; rosiglitazone (Avandia) =49; diet =15; insulin alone =55; insulin in combination with other oral hypoglycemic (OHG) agents =12; metformin alone =121; OHG combination =37; sulphonylurea =59) were included in this 12-month interventional study. All subjects were given 2000 IU vitamin D3 daily except the control group. Anthropometrics, glucose, lipid profile and 25-OH Vitamin D were measured at baseline, 6 and 12 months.
Results: T2DM subjects treated with Metformin raised vitamin D2 levels at 6 and 12 months compared with baseline (P<0.001). No significant changes were observed between Vitamin D2 levels and BMI, glucose, total- and HDL-cholesterol in any DMT2 groups. However significant decreases in triglycerides were observed in subjects treated with both rosiglitazone and insulin+OHG group at 6 and 12 month Vitamin D3 supplementation (both P values <0.001).
Conclusion: Whilst all groups increased circulating vitamin D2 following supplementation, it appears that DMT2 patients on insulin in combination with other OHG drugs heighten their Vitamin D3 absorption. As such Vitamin D3 taken with insulin plus OHG can offer benefits to reduce Vitamin D deficiency whilst improving cardiometabolic risk factors.
Declaration of funding: The study was generously funded by King Abdulaziz City of Science and Technology (KACST Grant no: AT-29-38), Riyadh, KSA for funding the study.