food science and gastroinstestinal physiology - 00230

food science and gastroinstestinal physiology - 00230 -...

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POPULATIONS THAT LIVE in the tropics receive enough ultraviolet (UV) light from the sun (top map, brown and orange) to synthesize vitamin D all year long. But those that live at northern or southern latitudes do not. In the temperate zones (light-shaded band), people lack sufficient UV light to make vitamin D one month of the year; those nearer the poles (dark shaded band) do not get enough UV light most months for vitamin D synthesis. The bottom map shows predicted skin colors for humans
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Unformatted text preview: based on UV light levels. In the Old World, the skin color of indigenous peoples closely matches predictions. In the New World, however, the skin color of long-term residents is generally lighter than expected probably because of their recent migration and factors such as diet. From Jablonski, Nina G., & George Chaplin. Skin deep. Scientific American 287 (4): 7481, October 2002....
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