There have been hospitals that denied Vit D to covid patients
The portion of the study posted does not suggest that someone with COVID benefits from vitamin D supplements. It refers to those with good Vitamin D levels beforehand, and Vitamin D is one of those that takes a long time to rise in the system, generally well beyond the scope of a COVID infection.
The initial studies I read a couple of years ago predominantly showed better outcomes if Vitamin D levels were not low, with high fatality rates if levels were <16ng. This meta study suggests that it also helps in not catching COVID to begin with.
By and large, it appears that Vitamin D is very good as a prophylactic in getting your base D levels up, but does not help much as a treatment.
When he was admitted, they called to get his list of meds AND supplements. I was so naive to assume that they work continue them. Anyway, after 2 days of discussing back and forth with various "hospitalists" one of them finally agreed to start him on 2000 units of D.
By this time, the Remdesivir and other protocol had done its damage. He passed away 2 weeks later.
You don't want that cash cow leaving any sooner than necessary. A patient cured is a customer lost.