Tanning is the physiological response stimulated by ultraviolet (UV) radiation from the sun’s rays. Exposure to UV rays increases the production of eumelanin, a type of melanin pigment that darkens the skin to protect it from damage. Different individuals’ tanning capacities vary, and can have positive and negative effects on the health of the skin.
People with less capacity are more prone to burns and sun spots, wrinkles, folate loss and melanoma, while people who tan easily are at risk for Vitamin D deficiency, because they can produce less Vitamin D in response to solar exposure.
The skin’s tanning capability is variable and is genetically determined. People with certain variants in genes related to pigmentation usually have light-coloured eyes and skin, and a reduced tanning capacity. Variations in the MC1R gene (melanin receptor) are the most determinant, and are associated with red hair, freckles, increased sensitivity to the sun and less tanning.