Retrospective 1,549 patients in Spain showing that the frequency of vitamin D deficiency was higher in admitted patients compared to the overall Spanish population, and that vitamin D deficiency was associated with increased risk of ICU admission amongst admitted patients. Adjusted vitamin D levels were lower in deceased patients, but statistical significance was not reached (authors provide only average levels, they do not provide mortality analysis based on deficiency).
Diaz-Curiel et al., 6/6/2021, retrospective, Spain, Europe, peer-reviewed, 8 authors.
risk of ICU admission, 73.2% lower, RR 0.27, p = 0.02, high D levels 3 of 214 (1.4%), low D levels 91 of 1017 (8.9%), odds ratio converted to relative risk, >30ng/mL vs. <20ng/mL.
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.