Vitamin D and intermittent fasting prevents and cures everything!
Just stop eating except for mega doses of Vitamin D and you could live as long as Methuselah.
I read it on Freerepublic and the Internet so it must be true.
And in addition to intermittent fasting do a Keto/Paleo/Carnivore diet and do Cross Fit 6x a week and invest all your money in Bit Coin :),
It is well established that Vit D is important to a strong immune system, among other things.
It was observed early in the pandemic that most getting seriously ill from Covid were Vit D deficient. That same can probable be said for many infectious diseases.
Weird that the CDC (or most Western health agencies) never promoted Vit D for Covid prevention. Similarly they didn’t promote other low-cost healthy lifestyle choices (weight-loss and exerciser) that also significantly reduce the risk/harm from Covid.