The CDC reports that Vitamin D is the #1 vitamin deficiency amongst the elderly, obese or overweight, and individuals with darker skin pigmentation. (*
Groups At Risk Of Vitamin D Deficiency) Interestingly, these are the very same people at higher risk for COVID 19 viral infection. (*
SARS/COVID 19 Research)
The benefits of Vitamin D cannot be fully explained here but what follows are the more important ones: