Related post by Scott Alexander: https://astralcodexten.substack.com/p/covidvitamin-d-much-mo...
> If it does prevent or cure coronavirus, great. If not, the worst that will happen is you'll have slightly better bone health.
Taking Vitamin D daily is like taking Vitamin C daily. Who knows if it actually helps, but we know it doesn’t hurt, so why not.
Edit: (as mentioned by commenters below, obviously don’t swallow more than the recommended dose on the bottle)
EDIT: It's worth noting that it takes a very high and frequent dose (60,000 IU daily, for instance, can cause it which is about 100x the recommended daily allowance of 600 IU).