Skin colour map (indigenous people). The twin role played by the skin – protection from excessive UV radiation and absorption of enough sunlight to trigger the production of vitamin D – means that people living in the lower latitudes, close to the Equator, with intense UV radiation, have developed darker skin to protect them from the damaging effects of UV radiation. In contrast, those living in the higher latitudes, closer to the Poles, have developed fair skin to maximize vitamin D production.