How does the skin make vitamin D and what limits its production?
Sun or UV light is the fuel that permits the body to manufacture vitamin D. But the amount of vitamin D formed in a given period of exposure depends on the color of your skin—that is, how rich your skin is in melanin. Melanin absorbs UV radiation. Therefore it diminishes the production of vitamin D. The darker a person’s skin, the longer he or she has to be in the sun or exposed to UVB radiation to form a significant amount of vitamin D (2). Like melanin, sunscreen also absorbs UV radiation and therefore greatly diminishes the skin’s vitamin D production. For example, sunscreen with a PDF of 8 diminishes a person’s ability to produce vitamin D by 95%. In addition, winter sunlight in the northern latitudes (New York City, Boston, and San Francisco) does not have enough UVB radiation to produce vitamin D in the skin. This is why many Americans are at risk for vitamin D deficiency, especially in the winter (3). A national study showed that 42% of African-American women ages 15 to 49 were
Sun or UV light is the fuel that permits the body to manufacture vitamin D. But the amount of vitamin D formed in a given period of exposure depends on the color of your skin-that is, how rich your skin is in melanin. Melanin absorbs UV radiation. Therefore it diminishes the production of vitamin D. The darker a person’s skin, the longer he or she has to be in the sun or exposed to UVB radiation to form a significant amount of vitamin D. Like melanin, sunscreen also absorbs UV radiation and therefore greatly diminishes the skin’s vitamin D production. For example, sunscreen with a PDF of 8 diminishes a person’s ability to produce vitamin D by 95%. In addition, winter sunlight in the northern latitudes (New York City, Boston, and San Francisco) does not have enough UVB radiation to produce vitamin D in the skin. This is why many Americans are at risk for vitamin D deficiency, especially in the winter. A national study showed that 42% of African-American women ages 15 to 49 were deficien
Sun or UV light is the fuel that permits the body to manufacture vitamin D. But the amount of vitamin D formed in a given period of exposure depends on the color of your skin- that is, how rich your skin is in melanin. Melanin absorbs UV radiation. Therefore it diminishes the production of vitamin D. The darker a person’s skin, the longer he or she has to be in the sun or exposed to UVB radiation to form a significant amount of the vitamin D. Like melanin, sun screen also absorbs UV radiation and therefore greatly diminishes the skin’s vitamin D production. For example, sun screen with PDF of 8 diminishes a person’s ability to produce vitamin D by 95% . In addition winter sunlight in the northern latitudes (New York City, Boston, and San Francisco) does not have enough UVB radiation to produce vitamin D in the skin. This is why many Americans are at risk for vitamin D deficiency, especially in the winter.
