What might be the correlation between Vitamin D blood levels and Covid19 severity?
That question has been ringing in my brain since I noticed the death rates in New York vs those in Florida – is it a latitude issue like seen in MS and other autoimmune disease, meaning correlated to the incidence of sunlight and consequently vitamin D levels in our tissues and blood? It seems I was not alone in this concern. Several studies are reporting that vitamin D status is important on both ends of the disease.

Low vitamin D levels is involved in susceptibility to infection, because the innate immune system is crippled by vitamin D deficiency. On the other end of the disease, vitamin D is a regulator of innate immune function and apparently tamps down the often fatal cytokine storm the virus causes in those with several comorbidities, such as obesity, diabetes, lung diseases and advanced age.

Here are links to three reports pointing to that idea:

https://www.sciencealert.com/covid-deaths-are-being-linked-with-vitamin-d-deficiency-here-s-what-that-means
https://www.medrxiv.org/content/10.1101/2020.04.08.20058578v3
https://www.sciencedaily.com/releases/2020/05/200507121353.htm

Points are made in these three that the cytokine storm or sepsis is what killed most who died of the virus, not the infection itself. The usual endless cautions that we really need more research before using this info clinically…etc. Practically speaking, 15 years of data on vitamin D as the backbone of our immune system has convinced me to test my vitamin D status and keep it at the top of the range (0-99 ng/ml), last measured at 76 ng/ml.