It would be tragic if taking vitamin D supplements had a negative effect on Covid survivability. I think that it is extremely unlikely, though possible unless

It would be tragic if taking vitamin D supplements had a negative effect on Covid survivability. I think that it is extremely unlikely, though possible unless a specific study has ruled this out. EG: Perhaps vitamin D supplementation upon Covid-19 diagnoses is only effective if you have not been supplimenting. Like: Maybe drinking alcohol at a party is helpful to court a new partner, unless you are an alcoholic already. Not the best analogy but I hope you'll take my point in good faith.