“Black Americans are dying of Covid-19 at a higher rate than whites. Socioeconomic factors such as gaps in access to health care no doubt play a role. But another possible factor has been largely overlooked: vitamin D deficiency that weakens the immune system.
Researchers last month released the first data supporting this link. Based on a link between levels of the inflammatory marker C-reactive protein and severe cases of Covid-19, they estimate that tens of thousands of lives could be saved world-wide by normalizing vitamin D levels, through its modulation of the inflammatory cascade.
Vitamin D is produced by a reaction in the skin to the ultraviolet rays in sunlight. Many Americans are low in vitamin D, but those with darker skin are at a particular disadvantage because melanin inhibits the vitamin’s production. As an Indian-American, my skin type is Fitzpatrick IV, or “moderate brown.” Compared with my white friends, I need double or triple the sun exposure to synthesize the same amount of vitamin D, so I supplement with 5,000 international units of vitamin D3 daily, which maintains my level in the normal range. Most African-Americans are Fitzpatrick type V or VI, so they would need even more.
This requires further study, but earlier research is suggestive. In 2018 a longitudinal study by researchers at Massachusetts General Hospital looked at whether vitamin D supplementation had any health benefits, specifically in regard to heart disease and cancer. The overall conclusion was that it didn’t, for most people. Yet buried in the results was one that should have made headlines: Vitamin D supplementation in African-Americans reduced cancer risk 23%. How? Cancer cells develop regularly in most animals, including humans, as the result of toxic injuries or glitches in DNA replication, but a healthy immune system destroys them. There is evidence that low vitamin D levels make the immune system go blind.”