Evaluation of the relationship between nutritional attitudes, vitamin D levels, and glycemic regulation in Type 2 diabetes patients admitted to Trakya University Hospital

Type 2 diabetes mellitus is a chronic metabolic disorder with a rising global prevalence, reduced quality of life, and a substantial burden driven by long-term complications. In addition to pharmacological treatment, nutritional attitudes, physical activity, and micronutrient status play essential roles in maintaining adequate glycemic control. This study aimed to investigate the association of nutritional attitudes and vitamin D levels with glycemic regulation among individuals with type 2 diabetes mellitus, using a descriptive and cross-sectional design. The study included 323 adults who presented to the Diabetes and Obesity Outpatient Clinic of Trakya University Faculty of Medicine Hospital between 1 October 2024 and 31 March 2025, had been diagnosed with type 2 diabetes mellitus for at least one year, and had recent measurements of glycated hemoglobin and serum 25-hydroxyvitamin D. Data were collected through face-to-face interviews using a questionnaire assessing sociodemographic characteristics, clinical features, and nutritional habits, along with the Nutrition Attitude Scale. Biochemical measurements were obtained from the hospital information system. Participants had a mean age of 60.3±11.1 years, and 52.9% were women. The mean serum 25-hydroxyvitamin D level was 23.0±9.8 ng/mL, the mean glycated hemoglobin was 7.7±1.7%, and the mean fasting glucose was 140.4±44.4 mg/dL. Nutritional attitude scores showed a significant positive correlation with serum 25-hydroxyvitamin D levels. Significant negative correlations were observed between serum 25-hydroxyvitamin D and both glycated hemoglobin and fasting glucose. These findings demonstrate that nutritional attitudes and serum 25-hydroxyvitamin D levels are key determinants of glycemic regulation. Strengthening lifestyle-oriented, patient-centered approaches within primary care may enhance metabolic outcomes and support the effective management of type 2 diabetes. Keywords: Diabetes Mellitus, Type 2; Vitamin D; Nutrition Assessment; Glycemic Control; Hemoglobin A, Glycosylated; Primary Health Care