I know the vitamin D deficiency theory has been discussed at length on HN but I don't know why it isn't brought up seriously in the cigarette discussion as well

I know the vitamin D deficiency theory has been discussed at length on HN but I don't know why it isn't brought up seriously in the cigarette discussion as well. This article just brushes it aside: > Note that the researchers seem to have been pursuing the good old Vitamin D chimera: the poor devils went looking in the fridge for milk and found a pack of Marlboro reds. It makes sense to me that smokers would be the one segment of the population that's consistently _not_ vitamin D deficient: they're forced to stand outside for 5-minutes several times a day while they smoke. Maybe it's the behavioral differences between smokers and non-smokers and not the cigarettes themselves. How do people who vape fare with Covid-19? They're presumably consuming the same (or more) nicotine as smokers but probably aren't going outside for every hit.