Exposure to ultraviolet light causes melanocytes to produce more melanin yielding a suntan. Why would sun exposure prompt this increased melanin production? In other words, what is the function of a suntan?

Question

Exposure to ultraviolet light causes melanocytes to produce more melanin yielding a suntan.  Why would sun exposure prompt this increased melanin production?  In other words, what is the function of a suntan?

Eva Anselmo · Accepted Answer

Melanin is a pigment that is able to absorb UV that would otherwise have caused harm to our skin

The body adjusts to the intensity of sunlight by producing more melanin to defend against cell damage when needed. UV is an ionizing radiation that can cause chemical reactions (i.e., free radicals) within cells that damage the genetic code, causing local cell damage and increasing the likelihood of inducing cancer. People who live near the poles produce less melanin (not very adaptive), while those who live near the equator produce more melanin (very adaptive). This is because proximity to the equator directly correlates with the intensity of sunlight (UV included).

Austin Alexander · Answer

undefined The increased melanin production triggered by sun exposure serves as a defense mechanism for the skin. Melanin helps to absorb and dissipate the harmful effects of ultraviolet (UV) radiation from the sun, thereby protecting the deeper layers of the skin from damage. A suntan essentially acts as a natural barrier against further UV damage, reducing the risk of sunburn and potentially lowering the risk of skin cancer.