• 96% of 23 vitamin D treatment studies report positive effects (13 statistically significant in isolation).
• Random effects meta-analysis with pooled effects using the most serious outcome reported shows 78% and 53% improvement for early treatment and for all studies
(RR 0.22 [0.12-0.43] and 0.47 [0.36-0.60]). Results are similar after restriction to 17 peer-reviewed studies
: 81% and 55% (RR 0.19 [0.06-0.61] and 0.45 [0.33-0.61]).
arises from many factors including treatment delay, patient population, the effect measured, variants, the form of vitamin D used, and treatment regimens. The consistency of positive results across a wide variety of cases is remarkable. The only treatment study reporting a negative effect is a very late stage cholecalciferol study.
• Sufficiency studies
show a strong association between vitamin D sufficiency and outcomes. Meta analysis of the 52 studies with pooled effects using the most serious outcome reported shows 53% improvement (RR 0.47 [0.40-0.55]).
• While many treatments have some level of efficacy, they do not replace vaccines and other measures to avoid infection. Only 4% of vitamin D treatment studies show zero events in the treatment arm. Multiple approaches are required to protect everyone from all existing and future variants.
• All data to reproduce this paper and the sources are in the appendix