Vitamin D Deficiency in Bipolar Disorder: Prevalence, Sociodemographic and Clinical Characteristics

OBJECTIVE: To assess the prevalence and severity of vitamin D deficiency in patients with bipolar disorder and examine potential associations with their sociodemographic and clinical characteristics. METHODS: A retrospective study was conducted on 185 inpatients aged 18-65, diagnosed with bipolar disorder and hospitalized at the Clinic for Psychiatry, University Clinical Center of Serbia, between 2022 and 2024. Data were obtained by analyzing medical records using the hospital information system "Heliant". RESULTS: Vitamin D deficiency was observed in 76.8% of patients, with 14.6% having severe deficiency, 36.8% deficiency, and 25.4% insufficiency. Significant associations were found between vitamin D deficiency and the autumn/winter season, as well as lower education levels. Additionally, manic episodes were more frequently observed during spring and summer. No other significant associations were identified. CONCLUSION: A high prevalence of vitamin D deficiency was found among patients with bipolar disorder. Routine screening and early intervention should be considered, including education, supplementation, and lifestyle modifications. Integrating preventive strategies into psychiatric care may improve clinical outcomes and mood stability. Further longitudinal and interventional research is needed to clarify the potential role of vitamin D and to guide evidence-based prevention and treatment in bipolar disorder.