This has been a big problem. Some people labeled science on vitamin D & covid19 as misinformation, lumping vitamin D in with things that have little to no evidence even when the vitamin D evidence was mounting rapidly. Part of the point of this open letter is to show that many serious people agree that vitamin D should be used in the pandemic. The inappropriate suppression of this message is now the mis-information. This should be clear from reading the letter and its very few references carefully.

See also the op-ed just posted to MedPage Today, and posted separately here on HackerNews: https://news.ycombinator.com/item?id=25680373