I think you have your wires crossed there.This sort of thing keeps cropping up on the benefits of maintaining Vitamin D levels. For those confined to a flat, who can't get out in the sunshine, perhaps a supplement is the way forward:
https://www.sciencedaily.com/releases/2017/02/170216110002.htm
and this one is a bit weird: it seems to suggest that smokers have a better chance of dealing with covid-19 even if they're going to succumb to other equally dreadful illnesses. Interestingly, as a kid, I had a hacking cough every winter which kept me awake most of the night for days on end. As soon as I started smoking, in the middle of one of these episodes, it stopped, never to return. Nevertless, I'm not ready to reach for the Old Holborn and liquorice papers just yet.
https://www.theguardian.com/world/2...-smokers-at-lower-risk-of-getting-coronavirus
They have come out to say Nicotine Patches may combat Covid-19 but smoking will just add to one's susceptibility of dying from it.