what does the skin produce in response to sunlight exposure
Sun tanning Moderate exposure to the sun contributes to the production of melanin and vitamin D by the body, but excessive exposure to ultraviolet rays has negative health effects, including sunburn and increased risk of skin cancer,[1] as well as depressed immune system function and accelerated aging of the skin. Some people tan or sunburn more easily than others. This may be the result of different skin types and natural skin color, and these may be a result of genetics.