Ghasemian et al., The International Journal of Clinical Practice,
doi:10.1111/ijcp.14675 (Peer Reviewed) (meta analysis)
The Role of Vitamin D in the Age of COVID-19: A Systematic Review and Meta-Analysis
Systematic review and meta analysis of 23 studies, finding significantly higher risk of COVID-19 cases and severity with vitamin D deficiency. Mortality risk was higher with deficiency, but not reaching statistical significance, OR 1.6 [0.5-4.4].
Ghasemian et al., 7/29/2021, peer-reviewed, 25 authors.