Vol. 3, Issue 2, Part A (2019)

Background and Objective: Vitamin D plays a crucial role in neurodevelopment and immune regulation. Its deficiency has been increasingly implicated in various psychiatric disorders, including schizophrenia. Seasonal variation in sunlight exposure may influence serum vitamin D levels, potentially affecting the course and severity of psychiatric symptoms. This study aims to assess the vitamin D status and its seasonal variation in patients diagnosed with schizophrenia attending a tertiary care hospital.
Material and Methods: A cross-sectional observational study was conducted on 60 patients diagnosed with schizophrenia (based on ICD-10 criteria) over a period of one year. This study was conducted at the department of Biochemistry, Madha Medical College and Research Institute, Kundrathur Main Road, Kovur, Chennai, Tamil Nadu, India from March 2017 to February 2018. Patients were stratified into two seasonal groups based on the time of presentation: summer (April-September) and winter (October-March). Serum 25(OH)D levels were measured using chemiluminescent immunoassay. Clinical severity was assessed using the Positive and Negative Syndrome Scale (PANSS). Patients with comorbid metabolic or endocrine disorders were excluded.
Results: Out of 60 patients, 32 (53.3%) were evaluated in winter and 28 (46.7%) in summer. The mean serum vitamin D level in winter was significantly lower (18.4 ± 5.3 ng/mL) compared to summer (25.9 ± 6.1 ng/mL) (p< 0.01). Vitamin D deficiency (<20 ng/mL) was observed in 71.9% of patients during winter and 39.3% during summer. A negative correlation (r = -0.45, p = 0.002) was found between vitamin D levels and PANSS scores, indicating higher symptom severity in deficient individuals.
Conclusion: Vitamin D deficiency is common in patients with schizophrenia and shows significant seasonal variation, being more prevalent during the winter months. Lower vitamin D levels were associated with greater symptom severity. These findings support the importance of monitoring vitamin D status in schizophrenia and considering supplementation, particularly during low sunlight periods.