Health Disparities and Vitamin D

Abstract

Research over the last two to three decades has slowly demonstrated that Vitamin D, a long neglected and unappreciated hormone, is of profound importance to human health and survival. Vitamin D begins its synthesis in human skin with ultraviolet B radiation (UVB) from the sun. Melanin is a potent UVB blocker, protecting the skin from the high intensity sunlight found on the tropical savannah into which humans evolved, but not impairing the skin's ability to synthesize generous quantities of vitamin D there. Adaptation to environmental availability of UVB radiation from the sun appears to explain the variation in skin melanin content in indigenous human populations around the world. Evidence shows populations in the United States have mean vitamin D levels that are associated with the relative amount of melanin in the skin in those populations, and that humans with insufficient levels of vitamin D suffer disproportionately from the diseases associated with health disparities. The differences in incidence and severity of cardiovascular diseases, the most common cancers, diabetes, tuberculosis, conditions associated with infant mortality, and total mortality in populations associated with health disparities in the United States are explored in this chapter. Indeed, the magnitude of the disparity in diseases associated with ''health disparities,'' related to the effect of vitamin D on those diseases, is such that eliminating the differences in vitamin D levels between the populations would appear to virtually eliminate the health disparities between them.

Solar UV Doses of Adult Americans and Vitamin D3Production

“…The AfricanAmericans have a similar situation from melanin protection, which may explain the disparity in health found between whites and blacks. 62 Furthermore, neither diet nor supplements correct this situation. [63][64][65] In fact, 83% of Australian dermatologists, who advise people to take vitamin D supplements rather than get more UV exposure, have insufficient blood levels of 25(OH) D. 66 Because the UV doses of indoor-working people around the world are similar to ours at similar latitudes (25-50°N), 58 vitamin D deficiency (<50 nmol/L or 20 ng/ml) and insufficiency (<75 nmol/L or 30 ng/ml) is also found around the world, especially at higher latitudes (>50°N) and in countries that do not fortify foods.…”

Importance of body weight and skin color in determining appropriate vitamin D3 supplement doses for children and adolescents

“…Skin color is one of the major determinants of vitamin D status because a given amount of sun exposure produces less vitamin D in darker skin than that in lighter skin (7,8). There is evidence that these differences in vitamin D levels are biologically related to US health disparities (6,(9)(10)(11)(12).…”