Research paper
Effects of Vitamin D Supplementation on COVID-19 Related Outcomes: A Systematic Review and Meta-Analysis
Study answer
What this study found
Primary prevention: Vitamin D supplementation did not significantly reduce risk of SARS-CoV-2 infection (RR 0.91; 95% CI 0.81–1.02; I2=0). Secondary prevention: insufficient data for hospitalization outcomes; one NRIS reported no significant effect on hospital admission (adjusted OR 1.30; 95% CI 0.51–3.32). Tertiary prevention (hospitalized patients): mortality reduced (RR 0.52; 95% CI 0.36–0.75; I2=54%) and ICU admission reduced (RR 0.35; 95% CI 0.20–0.62; I2=75%). Overall, mortality benefit (RR 0.52; 95% CI 0.36–0.75) was observed in tertiary prevention with some heterogeneity. Subgroup…
- Study & population
- Systematic review and meta-analysis.
- Intervention
- Vitamin D supplementation regimens included oral vitamin D3 (cholecalciferol) and active vitamin D forms (calcitriol, calcifediol), delivered as bolus, daily, or monthly dosing across primary, secondary, and tertiary prevention contexts.
- Key limitation
- High heterogeneity across studies (e.g., ICU mortality I2 up to 82%); reliance on non-randomized studies with risk of bias; wide variation in dosing regimens and populations; incomplete reporting for some outcomes; potential publication bias suggested by funnel plots; results not generalizable to children or younger…
View source
Open PDFOriginal abstract
The COVID-19 outbreak has rapidly expanded to a global pandemic; however, our knowledge is limited with regards to the protective factors against this infection. The aim of this systematic literature review and meta-analysis was to evaluate the impac…