The evidence continues to mount: Vitamin D will both help you avoid getting Covid-19 and make the symptoms less severe if you do get it. From Joseph Mercola at lewrockwell.com:
Vitamin D plays an important role in most diseases, including infectious disease, which is why from the very beginning of the COVID-19 pandemic, I suspected that optimizing vitamin D levels among the general population would significantly lower COVID-19 incidence and death.
Since then, mounting evidence reveals this is indeed the case, as researchers have repeatedly demonstrated that higher vitamin D levels reduce rates of positive tests, hospitalizations and mortality related to this infection.
Vitamin D3 Reduces ICU Admissions and Mortality
Most recently, a Spanish study1,2 (which has yet to undergo peer-review) found giving supplemental vitamin D3 (calcifediol) to hospitalized patients with PCR-confirmed COVID-19 reduced ICU admissions by 82% and mortality by 64%.3 People who already had higher vitamin D at baseline were 60% less likely to die.
The study included 930 patients, 551 of whom received vitamin D3 — 532 micrograms on the first day of admission followed by 266 mcg on days 3, 7, 15 and 30. The remaining 379 patients served as controls.