Serum 25-Hydroxyvitamin D Concentrations in Patients with Type 2 Diabetes Mellitus in Eastern Sudan: A Case-Control Study

Introduction Diabetes mellitus (DM) is one of the world's major public health problems. There are few published data on 25-hydroxyvitamin D (25[OH]D) concentrations and DM, and these studies showed different results. Objectives The current study aimed to compare 25[OH]D concentrations between patients with type 2 DM (T2DM) and healthy controls in eastern Sudan. Methods A case-control study of two groups matched for age and gender (88 in each group) was conducted in eastern Sudan from March to May 2022. The cases were patients with T2DM, and the controls were healthy participants. Sociodemographic data were collected, and serum 25(OH)D levels were assessed. A univariate analysis was performed. Results Of the total 176, 82 (47%) were males, and 94 (53%) were females; the median (interquartile range [IQR]) of age, body mass index (BMI), and 25(OH)D concentration were 55 (50-61) years, 27 (23-31) kg/m2, and 13 (10-19) ng/mL, respectively. Of the 176, 137 (78%) were vitamin D deficiency cases. Compared with the controls, age, gender, educational level, marital status, or BMI were not different in the circumstances. Moreover, the median (IQR) for serum 25(OH)D concentrations showed no difference between patients with T2DM and the healthy controls (12 [10-18] ng/mL vs. 13 [10-20] ng/mL). The prevalence of vitamin D deficiency (25(OH)D level < 20 ng/mL) was not different between patients with T2DM and the healthy controls (66/88 [75%] vs. 71/88 [81%]). There was no association in the serum 25(OH)D levels between diabetic and nondiabetic participants (OR = 1.01, 95% CI 0.97-1.06) or in vitamin D deficiency between diabetic and nondiabetic participants (OR = 0.72, 95% CI 0.35-1.47). Conclusion There was no significant difference in 25(OH)D levels between diabetic and nondiabetic participants in this study. Further studies investigating the mechanisms of association between 25(OH)D levels and DM are needed.