Correct. Vitamin D deficiency makes one more likely to get COVID-19 and more likely to have a severe case if you do get it. There really is a lot of evidence to support this, including studies from the NIH. Also, most people in the US are deficient in the winter and having a bit extra is considered harmless, so not suggesting it was always stupid.
There is also a traditional vaccine now that is completely ignored in the US. The ONLY acceptable response to COVID according to our government (and unfortunately one political side for reasons I don't understand) is one of the MRNA vaccines. Nothing else is acceptable even as an adjunct to those vaccines.
What has been shown in other studies is that giving hospitalized COVID patients vitamin D has no effect on outcomes. We could do studies that show the same lack of effectiveness for a lot of treatments including the vaccines. Once you're hospitalized it's too late for a lot of things.
