A Study on Serum Vitamin D3 Level in Patients with Covid-19: A Cross-Sectional Study in Kolkata

Background: Coronavirus disease (COVID-19) is a global pandemic caused by SARS-CoV-2. Vitamin D has immunomodulatory and anti-inflammatory properties, potentially influencing the disease course. This study assessed the prevalence of 25(OH) vitamin D deficiency in COVID-19 patients and its association with disease severity in the Indian population. Methodology: A hospital-based cross-sectional study was conducted at Medical College, Kolkata, including 100 RT-PCR-confirmed moderate and severe COVID-19 patients. Disease severity was categorized based on oxygen saturation. Serum 25-Hydroxy vitamin D levels were measured on admission, along with other hematological and biochemical parameters. High-resolution CT scans were performed to assess pulmonary involvement. Results: Vitamin D insufficiency and deficiency were observed in 18% and 67% of patients, respectively. Deficiency was more prevalent in severe cases (82.97%) than moderate cases (52.83%). The mean vitamin D levels in moderate and severe disease groups were 23.23±8.74 and 17.17±8.09 ng/ml, respectively. A significant association was found between vitamin D deficiency and COVID-19 severity (P = 0.006). The vitamin D cutoff for predicting severe disease was 18.57 ng/dl. Conclusion: Vitamin D deficiency is strongly associated with severe COVID-19 in the Indian population. Low vitamin D levels may predict disease severity, suggesting supplementation as a potential preventive strategy.