Vitamin D: Cheer Up, Spread Positivity!!
Those who have technical background in the medical, biology etc., areas can study this research paper, for example:
To briefly quote the paper:
"Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3"
But otherwise, there are dozens of such papers @ PubMed.
All those who have sufficient Vitamin D need to maintain that level. And, those who are running low on Vitamin D need to get under the SUN for at least 40mins in a day. Either walk or stand in the Sun. Best times are between Sunrise to Sunrise+2hrs, and in the evening between Sunset-2hrs to Sunset. more