I've just watched (well skipped through because he rambles) a Doctor John YouTube on Vitamin D.
The video is mind numbingly boring but the information is excellent.
79 people with known low Vit D were admitted to a hospital.
They gave them all the acknowledged best treatment but 50 of them had added vit D. So 50 had extra vit D and 26 'best' treatment.
The 26 that had the standard treatment 13 ended up in ITU and of those 2 died.
Those given the additional Vit D, 2 ended up in ITU and none died
That sounds pretty conclusive to me.
Get your vitamin D folk - and especially for older or more vulnerable people. D3 (not D2) in an oil base capsule. (Back it up with vit K2 if you can afford it) But vit D does so much for our health regardless of Covid. Please research it and consider it.