Retrospective 40 hospitalized pediatric COVID-19 patients and 45 healthy controls showing significantly lower vitamin D levels for COVID-19 patients (13.1 vs. 34.8µg/L), and that, within the hospitalized patients, there was more moderate and severe cases for patients with low vitamin D levels (non-statistically significant due to the small numbers).
Yılmaz et al., 10/5/2020, retrospective, Turkey, Middle East, peer-reviewed, 2 authors.
risk of severe case, 73.4% lower, RR 0.27, p = 1.00, high D levels 0 of 11 (0.0%), low D levels 2 of 29 (6.9%), >20ng/ml.
risk of moderate or severe case, 41.4% lower, RR 0.59, p = 0.69, high D levels 2 of 11 (18.2%), low D levels 9 of 29 (31.0%), >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