Association Between Glycemic Control Status and Serum Level of Vitamin D3 in Patients with Type 2 Diabetes: A Cross-Sectional Study

Abstract

Objective: This study aimed to assess the association between glycemic control status and serum levels of vitamin D3 in Iranian patients with type 2 diabetes (T2D). Materials and methods: This was a cross-sectional study on 452 patients with T2D in Tehran, Iran, performed between September 2019 and September 2020. We assessed the diabetes laboratory test and vitamin D3 level in all participants using the Enzymatic Glucose Oxidase method. Data were analyzed using SPSS version 24. Results: a total of 452 patients were enrolled in this study (mean age: 59.4 ± 11.4 years, 63.5% females). Vitamin D deficiency was reported in half of the participants. Deficient vitamin D was significantly associated with higher mean level of hemoglobin A1c, fasting plasma glucose, total cholesterol, and low-density lipoprotein-cholesterol (p < 0.05). Multiple regression showed that the level of vitamin D3 could be a good predictor of hemoglobin A1c after adjusting for confounding variables affecting the hemoglobin A1c (regression coefficient: 0.442, 95% CI, 0.072–0.811, p = 0.063). Conclusions: With the alarming rates of vitamin D deficiency in patients with T2D, there was a significant direct association between vitamin D3 and hemoglobin A1c levels before and after adjusting for the associated factors.