The production of Melanin in our body increases with the increase of the frequency and intensity of the exposure to the sun.
Melanocytes, cells located deep in the skin, produce it and their task is to free the melanin in the form of dark granules of pigment. These migrate into the adjacent cells (giving them the characteristic dark colour) and function by absorbing and rejecting most of the UV rays, thus protecting the cells from harm. Inside the melanocytes are special enzymes, such as Tyrosine, which have the task of favouring oxidation reactions necessary for the production of melanin from the Tyrosine amino acid.
Non homogeneous accumulations of melanin are behind the formation of brown spots on the face and body.