Survival implications vs. complications: unraveling the impact of vitamin D adjunctive use in critically ill patients with COVID-19—A multicenter cohort study

Retrospective 1,435 ICU patients in Saudi Arabia, showing no significant difference in mortality, and longer mechanical ventilation with treatment. Vitamin D patients had higher Q1, median, and Q3 SOFA scores after propensity score matching. 98% of patients were treated with cholecalciferol.

Cholecalciferol was used in this study. Meta analysis shows that late stage treatment with calcitriol / calcifediol (or paricalcitol, alfacalcidol, etc.) is more effective than cholecalciferol: 65% [41‑79%] lower risk vs. 39% [26‑49%] lower risk. Cholecalciferol requires two hydroxylation steps to become activated - first in the liver to calcifediol, then in the kidney to calcitriol. Calcitriol, paricalcitol, and alfacalcidol are active vitamin D analogs that do not require conversion. This allows them to have more rapid onset of action compared to cholecalciferol. The time delay for cholecalciferol to increase serum calcifediol levels can be 2-3 days, and the delay for converting calcifediol to active calcitriol can be up to 7 days.

This is the 115th of 120 COVID-19 controlled studies for vitamin D, which collectively show efficacy with p<0.0000000001 (1 in 248 sextillion).

This study is excluded in the after exclusion results of meta analysis: very late stage study using cholecalciferol instead of calcifediol or calcitriol.