Background and Aim: Vitamin D has metabolic functions in the cells, and its deficiency is considered a risk factor for many chronic diseases, such as type 2 diabetes. The present study aimed to determine the relationship of vitamin D intake from supplements and diet with fasting plasma glucose and HbA₁C in the patients with type 2 diabetes.

Material and Methods: This cross-sectional study included 500 subjects aged above 18 years with type 2 diabetes. Data were collected using demographic and food frequency questionnaires through interviews with patients. The data analysis was performed by linear regression, chi-square test and independent T-test.

Results: Among 500 patients in the study, 11 were excluded because of reports of high and low calorie values. Finally, 489 patients were entered into the study. 163 (33.3%) subjects were male and 326 (66.7%) were female. The mean age of the patients was 56.19±8.8. Vitamin D intake through supplements and diet was 5.82±3.5 mcg / day in the men and 6.30±3.4 mcg / day in the women. The mean fasting blood glucose and HbA₁C levels were 144.06±33.8 mg/dl and 7.34±1.1% respectively. Linear regression analysis showed that vitamin D intake had a significant  inverse association with fasting blood glucose (r= -0.26 and P=0.02) and HbA₁C (r= -0.37 and P<0.001).

Conclusion: In this study total vitamin D intake through diet and supplements had a significant inverse relationship with fasting blood glucose and HbA₁C, indicating the importance of vitamin D intake in blood glucose control in the patients with type 2 diabetes.

Keywords: Type 2 diabetes, Vitamin D intake,Fasting blood glucose, HbA₁C.

Received: Jun 19, 2016      Accepted: Aug 20, 2016