Background: Recently, there is evidence to suggest that altered vitamin D and calcium homeostasis may play a role in the development and control of type 2 DM. Objective: The aim of the current study was to evaluate the effect of vitamin D supplementation on glycemic control in type 2 DM patients.
Material and Methods: This is a Randomized controlled clinical trial. The study trial passed through two phases. Phase one: screening of diabetic patients to estimate the prevalence of suboptimal vitamin D level. Phase two: random allocation of diabetic patients with suboptimal vitamin D level to either vitamin D3 supplement or to no vitamin D3 supplement.
Results: In the current study, 248 type 2 diabetic patients had been screened for vitamin D deficiency. The great majority of diabetic patients had suboptimal level of vitamin D (98.4%).Two hundred Diabetic patients out of 248 with suboptimal level of vitamin D, were equally and randomly assigned to vitamin D supplementation group or control group. The duration of follow up was three. The comparison between different parameters before and after treatment with vitamin D3 in the treated group showed that the mean of vitamin D level had been increased significantly after treatment, from 24.96 nmol/L to 82.80 nmol/L), P<0.001. There were no significant improvement or worsening in glycemic control in both groups. The mean of the diastolic blood pressure has been decreased significantly after treatment, from 76.43 mm/hg to 73.25 mm/hg, P=0.021.
Conclusion: According to our study the administration of vitamin D did not significantly improve type 2 DM indicators (glycosylated hemoglobin and fasting blood glucose), lipid profile of type 2 diabetic patients and their BMI in three months.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.