I’d suggest reading this series of blog posts on Vitamin D by Dr. Deva Boone (they were also shared here before): https://www.devaboone.com/ https://www.devabo

I’d suggest reading this series of blog posts on Vitamin D by Dr. Deva Boone (they were also shared here before): https://www.devaboone.com/ https://www.devaboone.com/ If you’re deficient or not getting enough exposure to the sun around midday, then supplementing could be useful. As a preventative measure for COVID-19 or as a measure to make COVID-19 less severe (or for reducing the risk of any other ailment), the blog posts cited above conclude that there is no evidence. There are correlations, but we know that correlation does not necessarily mean causation. Please read the blog posts and arrive at your own conclusion.