et al., Journal of Endocrinological Investigation, doi:10.1007/s40618-021-01639-9 (Peer Reviewed)
Retrospective study of cholecalciferol and calcitriol supplementation in Catalonia showing a small but significant lower risk of cases with cholecalciferol, but no significant difference for mortality, or for calcitriol supplementation. Significant benefit was found for cases, severity, and mortality in patients achieving serum vitamin D levels ≥30ng/ml.
Oristrell et al., 7/17/2021, retrospective, Spain, Europe, peer-reviewed, 8 authors, dosage varies (calcifediol).
risk of death, 1.0% higher, RR 1.01, p = 0.91, calcifediol, univariate.
risk of death, 4.0% lower, RR 0.96, p = 0.37, cholecalciferol, univariate.
risk of COVID-19 case, 1.0% lower, RR 0.99, p = 0.65, calcifediol, univariate.
risk of COVID-19 case, 5.0% lower, RR 0.95, p = 0.004, cholecalciferol, multivariate.
Effect extraction follows pre-specified rules
prioritizing more serious outcomes. For an individual study the most serious
outcome may have a smaller number of events and lower statistical signficance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.