Effects of 12-month, 2000IU/day vitamin D supplementation on treatment naïve and vitamin D deficient Saudi type 2 diabetic patients.

Objectives: To determine whether 12-month, 2000IU/day vitamin D supplementation cardiometabolically improves treatment naïve type 2 diabetes mellitus (T2DM) Saudi patients with vitamin D deficiency. 

Methods: This 12-month interventional study was conducted at primary health centers in 5 different residential areas in Riyadh, Saudi Arabia between January 2013 and January 2014. Forty-five Saudi  T2DM  patients were enrolled. Baseline anthropometrics, glycemic, and lipid profiles were measured and repeated after 6 and 12 months. All subjects were provided with 2000IU vitamin D supplements for one year.  

Results: Vitamin D deficiency at baseline was 46.7%, 31.8% after 6 months, and 35.6% after 12 months, indicating an overall improvement in the vitamin D status in the entire cohort. Insulin and homeostatic model assessment-insulin resistance (HOMA-IR) after 12 months were significantly lower than a 6 months (p less than 0.05), but comparable to baseline values. Mean levels of triglycerides increased overtime from baseline (1.9±0.01 mmol/l) to 12 months (2.1±0.2 mmol). This modest increase in serum triglycerides was parallel to the insignificant decrease in circulating high-density lipoprotein -cholesterol levels. 

Conclusion: Twelve-month vitamin D supplementation of 2000IU per day in a cohort of treatment naïve Saudi patients with T2DM resulted in improvement of several cardiometabolic parameters including systolic blood pressure, insulin, and HOMA-IR. Further studies that include a placebo group are suggested to reinforce findings.