Serum 25(OH)D Levels and Covid-19 Risk, Severity, and Mortality
Eight studies investigated the association between 25(OH)D levels and risk of Covid-19. All studies showed an increased risk of Covid-19 in those with low 25(OH)D levels (summary relative risk (SRR) = 2.18 (95% CI: 1.55-3.06)).Sixteen studies investigated the association between 25(OH)D levels and COVID-19 severity and found a significant increased risk of severe disease for those with low serum 25(OH)D levels (SRR = 2.38, 95% CI: 1.53-3.70).
Nineteen studies investigated the association between 25(OH)D levels and Covid-19 mortality and found a significant increased risk of death for those with low 25(OH)D levels (SRR = 2.35, 95% CI: 1.46-3.80).
Vitamin D Supplementation and COVID-19 Severity and Mortality
Six studies investigated the association between vitamin D supplementation and Covid-19 severity and found a significant 62% reduction of severe disease with vitamin D supplementation (SRR = 0.38, 95% CI: 0.20-0.72).Seven studies investigated the association between vitamin D supplementation and Covid-19 mortality and found a significant 65% reduction in the risk of death for subjects supplemented with vitamin D (SRR = 0.35, 95% CI: 0.17–0.70).