Prevalence of vitamin D deficiency in patients with type 2 diabetes and its relationship with glycemic control

Abstract

Aim: The aim of our study is to investigate serum 25-hyrdoxy (OH) vitamin D levels in patients with type 2 diabetes, determine the prevalence of vitamin D deficiency, and reveal the potential relationship between vitamin D deficiency and glycemic control. Material and Methods: A total of 100 patients (50 females, 50 males) diagnosed with type 2 DM were included in the study. Data used in the study were retrospectively acquired from the records in the files of patients who had presented to the General Internal Medicine polyclinic and clinic at Firat University Hospital. Results: Mean vitamin D levels were determined as 11.8 ± 5,8 nmol/l in females and 13.5 ± 7.3 nmol/l in males. 57 patients (57%) in total demonstrated vitamin D deficiency. Vitamin D deficiency was detected in 31 (62%) female patients and 26 (52%) male patients. A significant negative correlation was determined between diabetic patients with and without vitamin D deficiency with regard to HbA1c, fasting blood glucose, post-prandial blood glucose (p<0.001). Diabetic patients with vitamin D deficiency and diabetic patients without vitamin D deficiency demonstrated no significant differences with regard to retinopathy, nephropathy, and neuropathy (p>0.05).A significant negative correlation was determined between diabetic patients with and without vitamin D deficiency with regard to BMI and patient weight (p<0.001). Conclusion: Our study concludes that vitamin D has a negative significant correlation with FBG, PPBG, HbA1C, and BMI. These results indicate that, as vitamin D levels decrease in patients with type 2 diabetes, insulin resistance increases, and consequently, glycemic control is disrupted. Although, along with our study, other studies too have reported an increased risk for Type 2 diabetes in the presence of vitamin D deficiency, evidence suggesting a causal relationship is limited as not an adequate number of high-quality randomized controlled studies exist.