The above is perhaps a strong possible as to why UC is never ending.
Here is a bit more of which may be related,I think.
Old mike
https://europepmc.org/article/pmc/pmc3923390PS: By the way start searching covid vitamin D.
You will find some interesting info. Also on google hit the news button.
Post Edited (Old Mike) : 9/16/2020 10:58:24 AM (GMT-6)