Just in case you, like me, wondered whether this was just a high base rate of vitamin d deficiency: no, vitamin d deficiency is common but not that common.
How high does the base rate need to be in order to explain most COVID deaths?
Note that your reference defines deficiency as less than 20 ng/mL, but correlation studies suggest using 30 ng/mL as the COVID-relevant threshold for deficiency.
Just in case you, like me, wondered whether this was just a high base rate of vitamin d deficiency: no, vitamin d deficiency is common but not that common.
How high does the base rate need to be in order to explain most COVID deaths?
Note that your reference defines deficiency as less than 20 ng/mL, but correlation studies suggest using 30 ng/mL as the COVID-relevant threshold for deficiency.