Hopefully, I will soon write some more about vitamin D levels in the blood and about supplementing [really with some trepidation..!]
Of course, the Internet is overflowing with this relatively new subject.
Let me just suggest for the moment that likely the best and safest levels are somewhere between 30-40 ng, much higher levels are not better [and maybe less safe] at least if these levels are reached by supplements. This has been shown in various studies.
Never before has vitamin D been given so much attention by the medical profession as during “our Corona” time.
I suppose that if populations have higher levels WITHOUT supplementing synthetic vitamin D that this should be safe as well.