Statistically significant lower risk is seen for recovery and cases. 7 studies from 6 independent teams in 3 countries show significant improvements.
Meta analysis using the most serious outcome reported shows 36% [6‑56%] lower risk. Results are similar for Randomized Controlled Trials, higher quality studies, and peer-reviewed studies. Results are consistent with early treatment being more effective than late treatment.
6 sufficiency studies analyze outcomes based on serum levels, showing 80% [52‑92%] lower risk for patients with higher vitamin A levels.
In exclusion sensitivity analysis, statistical significance is lost after excluding 2 of 14 studies in pooled analysis.
The European Food Safety Authority has found evidence for a causal relationship between the intake of vitamin A and optimal immune system function1,2.
No treatment or intervention is 100% effective. All practical, effective, and safe means should be used based on risk/benefit analysis. Multiple treatments are typically used in combination, and other treatments may be more effective. The quality of non-prescription supplements can vary widely3,4.
All data to reproduce this paper and sources are in the appendix.
Covid Analysis et al., Jul 2024, preprint, 1 author.
