Role Of Vitamin D Deficiency In Type 2 Diabetes: Association Or Coincidence?

Background. Vitamin D has received considerable attention for its possible role in myriad of clinical conditions especially non-communicable chronic diseases. However, it is the role in the pathogenesis of type 2 diabetes (T2DM), which has generated a lot of enthusiasm to unravel the association between the two.Aim. To determine the prevalence of hypovitaminosis D and its relation with the glycemic control in T2DM patients attending a tertiary care hospital in Kashmir.Methods. A total of 108 cases of T2DM and 101 healthy controls aged between 35-65years were investigated in this study. 25-hydroxyvitamin D (250HD), glycosylated hemoglobin (HbA(1c)) and fasting serum insulin levels were determined using standardised and automated assays. Insulin resistance (IR) and beta-cell function (B) were estimated by the homeostasis model assessment (HOMA).Results. The mean serum level of 250HD was significantly lower in T2DM group compared to controls (20.55 +/- 12.27 vs 27.62 +/- 5.32 ng/mL; P = 0.001). The prevalence of hypovitaminosis D was significantly higher in patients with T2DM (79.5% vs 62.7%; P = 0.031). Overall 51.1% and 28.4% patients with diabetes and 41.2% and 21.6% controls had vitamin D deficiency and insufficiency respectively.Vitamin D was found to have a significantly positive association with serum fasting insulin level and HOMA-B in both cases (P = 0.019), (P = 0.026) and controls (P = 0.022), (P = 0.008) respectively. Prolonged glycemic control as determined by HbA(1c) demonstrated a significant inverse correlation with vitamin D level in both cases (r = -0.225;P = 0.035) and controls (r = -0.373; P = 0.007).Conclusion. We conclude that vitamin D deficiency (VDD) is a very common health problem and is relatively more common in patients with T2DM. There is an inversed association between vitamin D and glycemic control. Vitamin D status thus appears to affect glucose homeostasis. Vitamin D screening and supplementation is a plausible way to mitigate the impact of VDD on glucose homeostasis in T2DM.