COVID-19 Mortality Risk Correlates Inversely with Vitamin D3 Status, and a Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3: Results of a Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined the relationship between serum 25-hydroxyvitamin D3 [25(OH)D3] levels and COVID-19 mortality. Analyzing data from one population study and seven clinical studies, the authors found a significant inverse correlation between vitamin D3 levels and mortality risk. The combined data suggested that a serum 25(OH)D3 level