How about this? It's a release of preliminary data from a retrospective study done on Covid-19 patients in Indonesia. Very simple arms: Those who lived versus those who died. They found the usual strong correlations with sex, age, and co-morbidities, but they also had Vitamin D blood levels. When they factored out the other things, they found that patients with low Vitamin D levels were over 10 TIMES as likely to die, than patients with normal levels (>30 ng/ml). That not 10%, it's 10 times.
Indonesia Preliminary Results This has not been peer-reviewed yet, but their analysis looks pretty reasonable. If it's true, it means we could probably cut our death rates by 10 times just by correcting everybody's Vitamin D levels. And a huge percentage of people in the US have Vitamin D insufficiency or actual deficiency. In particular, a lot of people with dark skin can't make much from our non-tropical sunlight and inside work. Also more than half the elderly have deficiency!
Correcting your Vitamin D level is usually as simple as taking 2500 iu per day of Vitamin D3. I actually take about 8000 iu per day for my MS but I do monitor my blood level. I doubt 2500 iu per day could harm anybody unless their doctor has warned them not to take it.
