Factors Associated with Depressive Symptoms among Rural Korean Adults: Analysis of the 2022 KNHANES

Purpose: This study investigated the factors associated with depressive symptoms among adults residing in rural South Korea, with particular attention to the potential role of serum vitamin D levels. Methods: A cross-sectional analysis was conducted using data from the 2022 Korea National Health and Nutrition Examination Survey (KNHANES). A total of 532 adults aged 19-64 years living in rural areas were included. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and serum 25-hydroxyvitamin D3 [25(OH)D3] levels were measured through laboratory testing. Logistic regression was performed to evaluate associations, adjusting for sociodemographic, behavioral, and clinical variables. Results: No significant association was found between serum vitamin D levels and depressive symptoms. However, several factors were independently associated with greater odds of depressive symptoms, including younger age, female sex, low education level, low household income, frequent alcohol consumption, presence of chronic disease, and high perceived stress. Among these, perceived stress showed the strongest association with depressive symptoms. Conclusion: These findings suggest that psychosocial and health-related factors may have a stronger influence on depression in rural populations than serum vitamin D levels. Public health strategies aimed at reducing stress, managing chronic disease, and alleviating economic hardship may be more effective in improving mental health outcomes in rural settings. Further longitudinal studies are warranted to explore the role of vitamin D in more vulnerable subgroups.