Effect of vitamin D supplementation on glycosylated hemoglobin in patients of type 2 diabetes mellitus taking oral antidiabetic drug metformin

Objectives: To assess the outcome of vitamin D as adjunctive therapy in reducing the serum level of glycosylated hemoglobin (HbA1C) in type 2 diabetic patients taking anti-diabetic drug metformin. Study Design: An Observational study. Setting: This study was conducted at the Department of Pharmacology, Liaquat University of Medical and Health Sciences Jamshoro in collaboration with Sindh Institute of Endocrinology & Diabetes (SIED) Liaquat University of Medical and Health Sciences Jamshoro. Period: December 2017 to May 2018. Material and Methods: We carried out this study on 140 patients. Diagnosed patients of type 2 DM With duration more than 5 years, age between 35 to 60 years, HbA1c equal to or more than 6.0%, and diabetic patients which were on metformin and had vitamin D deficiency (level less than 30ng/ml) were included in the study. Results: Total 140 type 2 diabetic patients were taken in study. At baseline, in Group B, mean HbA1c ± SD was 7.92±1.54 while at 3 months intervention, in Group B, mean HbA1c ± SD was 7.18±1.53. No significant difference in HbA1c between Group A and B at baseline and after three months of intervention (P value = 0.46). The mean value of vitamin D before supplementation was 16.23±3.45 vs 28.96±5.25 after 3 months supplementation. There was a significant increase in 25 (OH) D levels after vitamin D supplementation after 3 months. (P < 0.0001). Conclusion: Supplementation of vitamin D did not show any effect on blood sugar control in our patients with type 2 DM.