This is a very important study on vitamin D and Covid-19. Its findings are incredibly clear. An 80% reduction in need for ICU and a 60% reduction in deaths, simply by giving a very cheap and very safe therapy - calcifediol, or activated vitamin D. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3771318#
The findings of this large and well conducted study should result in this therapy being administered to every Covid patient in every hospital in the temperate latitudes.
Furthermore, since the study demonstrates that the clear relationship between vitamin D and Covid mortality is causal, the UK government should increase the dose and availability of free vitamin D to all the vulnerable groups.
These approaches will save many thousands of lives. They are overdue and should be started immediately.