The effects of plasma levels of vitamin D3 on insulin resistance and biochemical factors of plasma in patients with type 2 diabetes

The prevalence of diabetes mellitus due to existence of various factors is growing rapidly. The insulin resistance phenomenon is one of the main underlying causes of this disease, due to various reasons such as a decrease in serum levels of vitamin D3. In this study, we evaluated the relationship between plasma level of vitamin D3 and some other main plasma factors.
This clinical trial study carried out on type 2 diabetes mellitus subjects who referred to diabetes clinic of Baqiyatallah Hospital in Tehran city during June to September 2016. First demographic data of all patients were collected. Then the blood samples for evaluation of blood glucose, HbA1c, triglyceride, cholesterol, HDL, LDL and vitamin D3 were obtained. Based on plasma level of vitamin D3, diabetic subjects were divided into two separate treatment groups (with and without vitamin D3 deficiency) and then above-mentioned factors were compared between these two groups. Afterward, in group with vitamin D3 deficiency, treatment by vitamin D3 triggered (50000 unit per week for eight weeks orally) until plasma level of vitamin D3 reached above 30 ng/mL. Then, treatment continued by vitamin D3 (50000 Unit per week orally) and calcium (1.5 g/day PO) until 60 days. Finally, the patients were evaluated about fasting blood glucose, HbA1c, HDL, LDL and blood pressure.
In total, 187 subjects (99 men and 88 women) were evaluated in this study. Total hypovitaminose incidence was 0.65% which was higher in subjects with higher body mass index (BMI). Serum content of vitamin D3 and calcium, significantly changed the values of fasting blood sugar (FBS), HbA1c, HDL and TG, but has no significant effects on other factors.
Our results clearly revealed that hypovitaminose vitamin D3 is one of the main factors that can leading to rise in plasma glucose and dyslipidemia occurrence. Also, our data are demonstrated that treatment by vitamin D3 and calcium can modify fasting blood glucose and dyslipidemia in type 2 diabetes mellitus subjects.