Vitamin D Status and Its Association with Blood Glucose Parameters Among Indian Diabetic Patients: a Non-Interventional, Cross-Sectional, Observational Study

Abstract

Introduction

The aim of the study was to evaluate vitamin D status and its association with blood glucose parameters in Indian diabetic patients.

Materials and methods

This cross-sectional, non-interventional, single visit program was conducted across 236 sites in India where 4434 (males: 2580; females: 1854) diabetic patients of 18-65 years of age who had undergone testing for vitamin D and blood glucose in the last 3 months were recruited in the study. Anthropometric and metabolic parameters, and serum 25-hydroxyvitamin D (25[OH]D) was measured. The patient was said to have ‘non-optimal level of vitamin D’ if had serum 25(OH)D <30 ng/mL (‘vitamin D deficient’ <20 ng/mL, ‘vitamin D insufficient’ 20-29 ng/mL) and was said to have ‘optimal level of vitamin D’ if the level was ?30 ng/mL. Descriptive statistics was used in the study. Results

99.0% patients had type 2 diabetes and 1.0% patients had type 1 diabetes mellitus. 81.7% of the patients had ‘not optimal’ level of 25(OH)D where 41.5% patients had 25(OH)D deficiency and 40.2% patients had 25(OH)D insufficiency and 18.3% of the patients had ‘optimal’ level of 25(OH)D. Mean level of 25(OH)D was 22.1 ± 7.9 ng/mL. Higher proportion of patients with ‘not optimal’ level of 25(OH)D had a higher range of fasting plasma glucose (FPG; 135-298 mg/dL), glycated hemoglobin (HbA1c; 8.3-13.8%), and postprandial glucose (PPG; 217-299 mg/dL) as compared to patients with ‘optimal’ level. In addition, a negative correlation was found between 25(OH)D levels and calcium and a positive correlation with height and body mass index.

Conclusion

Despite an ample amount of sunlight in the country, 81.7% of Indian diabetic patients had deficient or insufficient levels of vitamin D (25[OH]D <30 ng/mL). The level of vitamin D had a negative correlation with FPG, PPG, HbA1c and serum calcium; suggesting that vitamin D supplementation may improve glycaemic control in diabetic patients.