> *Given that a lot of the COVID morbidity and mortality is the cytokine storm r...

> Given that a lot of the COVID morbidity and mortality is the cytokine storm rather than the infection itself, I wouldn't consider it a priori clear that Vitamin D helps, is neutral, or harms patients who get COVID.

Autocrine vitamin D signaling switches off pro-inflammatory programs of cells: https://www.nature.com/articles/s41590-021-01080-3