The role of vitamin D in outcomes of critical care in COVID-19 patients: evidence from an umbrella meta-analysis of interventional and observational studies.
Level 1 - systematic review of randomized trials
Umbrella meta-analysis synthesizing existing meta-analyses of randomized trials and observational studies
PubMed 38654693 · doi:10.1017/S1368980024000934
What was done
Umbrella meta-analysis systematically searching Web of Science, PubMed, Scopus, and Embase through March 2023 for meta-analyses examining vitamin D status and supplementation in adult COVID-19 patients. Methodological quality was evaluated using AMSTAR tools, and pooled estimates were synthesized using random-effects models.
What was found
Thirteen meta-analyses were included, summarizing data from 4 randomized controlled trials and 9 observational studies. Vitamin D supplementation significantly reduced COVID-19 mortality in interventional meta-analyses (effect size [ES] = 0.42; 95% CI: 0.10, 0.75, P < 0.001; I2 = 20.4%, P = 0.285). Observational meta-analyses showed that vitamin D deficiency significantly increased COVID-19 mortality (ES = 1.99; 95% CI: 1.37, 2.62, P < 0.001; I2 = 0.0%, P = 0.944). The abstract reports that deficiency also increased infection risk, disease severity, ICU admission, and mechanical ventilation detachment time, but reports no numerical data for these secondary outcomes.
Why it matters
This umbrella review synthesizes existing meta-analytic evidence, showing consistent statistical associations between vitamin D supplementation or adequate status and lower COVID-19 mortality across both randomized and observational literature.
Limits
The interventional evidence base was small, drawing on only 4 underlying randomized controlled trials across the included meta-analyses. The abstract does not specify the precise effect metric used (e.g., odds ratio vs. relative risk), baseline vitamin D levels, dosing regimens, timing of administration, or the extent of primary study overlap across meta-analyses.
Cited by
- supports Observational studies show that COVID-19 patients with vitamin D deficiency had higher rates of hospitalization, mechanical ventilation, and mortality.