Abstract
Background: Hypovitaminosis D has been reported as a risk factor for glucose intolerance. Although traditionally named as sunshine vitamin, in India, it is paradoxically deficient. Obesity is frequently associated with insulin resistance (IR) and prediabetes and other components of metabolic syndrome. Obesity is also commonly associated with hypovitaminosis D due to the capacity of adipose tissue to store 25-dihydroxy vitamin D making it biologically unavailable.

Aims and Objectives: This study is designed to know the prevalence of hypovitaminosis D and study its relation with IR from Central India.

Materials and Methods: A total of 594 patients were enrolled in the study. Of these, 560 met inclusion-exclusion criteria. Body mass index (BMI), Waist-hip ratio, and blood pressure were measured. Fasting sample was taken for the following investigations: Fasting blood sugar, fasting insulin, intact parathormone, lipid profile, and vitamin D were done. Homeostatic model assessment (HOMA-IR) was calculated. Based on BMI, they were divided into two groups: Cases (n = 168) with BMI >25 and controls (n = 392) BMI <25.

Results: Overall vitamin D deficiency was seen in 413 (73.75%) with deficiency in cases 93.45% and 65.3% in control group. Severe vitamin D deficiency was seen in 14.88% cases and 11.99 controls. Mean serum vitamin D levels were 18.31 ± 11.53 in cases and 26.4 ± 12.28 0.002 (HS) in controls. Vitamin D sufficiency was seen in only 6.54% of cases and 34.69% of controls. Individuals with severe vitamin D deficiency have maximum IR. The parameters of IR were significantly seen to be associated with vitamin D levels.

Conclusion: Vitamin D deficiency is rampant in Central India and shows strong independent association with IR.

Key words: Vitamin D3; Insulin Resistance; Hypovitaminosis D; 1,25-dihydroxy Vitamin D3