A group of Health Science and Medical experts from the U.K., U.S. and Europe have sent an open letter to world Governments stating that there is clear evidence that Vitamin D reduces Covid-19 infections, hospitalizations and deaths. The letter indicates that global patterns and risk factors for the COVID-19 pandemic and Vitamin D deficiency match precisely due to the impact on immune function. This group of scientists are calling for immediate and widespread increased intakes of Vitamin D i.e. 4000 iu per day.
The main organisers Dr. Karl Pfleger (USA) and Dr. Garreth Davies (UK) have published the letter here