Serum 25-hydroxyvitamin D levels and health outcomes of hospitalization owing to COVID-19: a retrospective cross-sectional study

Objective: We investigated the role of serum 25(OH)D (25-hydroxyvitamin D) in COVID-related health outcomes. Methods: We conducted a retrospective cross-sectional study using data of the National Center of Disease Control and Public Health, Georgia. We extracted patient data including length of hospital stay, transfer to the intensive care unit, requirement for oxygen therapy, treatment with glucocorticoids, and symptoms. After obtaining written informed consent, 384 individuals were enrolled. We divided participants into three groups according to 25(OH)D levels: group 1 = 25(OH)D <12 ng/mL (n = 83), group 2 = 25(OH)D 12-20 ng/mL (n = 141), and group 3 = 25(OH)D >20 ng/mL (n = 160). Results: The odds ratio (OR) for hospitalization in group 1 versus group 2 was 8.7 (95% confidence interval [CI] 3.6-21.3) and 5.6 for group 1 versus 3 (95% CI 2.7-11.9). Regarding oxygen therapy, OR = 28.41 for group 1 versus 2 (95% CI 3.7-220.5) and OR = 5.2 for group 1 versus 3 (95% CI 1.9-14.1). Regarding treatment with glucocorticoids, OR = 3.7 for group 1 versus 2 (95% CI 1.1-12.5) and OR = 8.4 for group 1 versus 3 (95% CI 1.8-40.7). Conclusion: COVID-19-related morbidity was associated with decreased serum 25(OH)D levels. Future studies should investigate the potential role of vitamin D sufficiency in preventing SARS-CoV-2 infection and mortality.