If you have a high enough Vitamin D level, you are pretty much guaranteed not to die, and your chances of contracting the disease is low, as well as the severity.
Take zinc, too!
No.
Vitamin D has a desired level. That level has been shown to provide proper immune system performance. Not extra. Proper. Lower has been associated with many diseases that arise from poor immunity.
Additional Vitamin D is not a matter of more is better. Vitamin D has calcium consequences and that is the pathway to kidney issues.
You get your level normal. You don’t go beyond that.
Note that 80% of vitamin D levels are generally below normal so it’s not silly to supplement, but studies are all over the place as regards toxicity with too much supplement.
So just don’t do it. Get the level to normal and keep it there. Don’t go higher. What does this do for COVID. There is no data. Only on generic immunity.