The benefits of sunlight for Vitamin D3 synthesis in the skin are unequal and itʻs complicated.
√ The US has distinct solar zones and they follow the Latitude and the climate.
√ In the light green zone flowing West to East from central Oregon down to St. Louis and up to New York, it is very difficult to obtain sufficient Vit. D3 from solar exposure to exposed skin.
√ In the SW state and in the South Solar intensity is sufficient for D3 synthesis with light skin tone and full body exposure 20 mins per day.
√ On the same map, the circles show the density of COVID 19 deaths. Suggesting that a major reduction in solarized skin may be a factor in mortality
√ The middle map depicts the population density of African Americans. This ethnicity requires more solarized skin time to produce the Vitamin D3 of lighter skin tone people. That is to suggest that the darker skin toned people are more likely to be D3 deficient.
√ There is data to suggest that lower Vit D3 levels are risk factors for COVID19 co-morbidities as well is the severity of the virus infection itself.