Evaluation of Serum Levels of Vitamin D in Patients with Type 2 Diabetes Mellitus on Metformin Therapy: A Cross-Sectional Controlled Study

Abstract

BACKGROUND Vitamin D is well-known for its primary dominant role in maintaining calcium and phosphate concentrations in blood, yet it is associated with the stimulation of insulin secretion from pancreatic beta cells.OBJECTIVE The aim of the study is to measure serum level of vitamin D and to investigate its relationship with other parameters in type 2 diabetes mellitus patients.SUBJECTS AND METHODS: This is a cross-sectional controlled study was carried out during the period from December 2021 to the end of March 2021 at private internal medicine clinics in Tikrit city, Iraq. The study included 90 participants, 60 type 2 diabetes mellitus patients on metformin therapy designated as (metformin group) and 30 type 2 diabetes mellitus without metformin therapy considered as (control group). Blood samples were assessed for serum vitamin D using Cl-900i Chemiluminescence Immunoassay Analyzer and glycated hemoglobin HbA1c using AFIAS Analyzer in all metformin and control group.RESULTS:The study showed no significant difference in serum vitamin D and HbA1c levels between metformin and control group. Highly Significant negative correlations were found between vitamin D and diabetes mellitus (DM) duration and HbA1c (P < 0.01, P < 0.001, respectively). Significant negative correlations were found between vitamin D and metformin dose (P < 0.05, respectively). CONCLUSION: The results showed that type 2 diabetic patients had low vitamin D levels and strongly validate the role of vitamin D deficiency in etiology of type 2 diabetes mellitus. Correction of vitamin D may help to improve disease outcome.