PATHOLOGY

Detailed explanation-1: -Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.

Detailed explanation-2: -The epidermis is the major source of vitamin D for the body. Under the influence of sunlight (ultraviolet radiation, action spectrum 280–320nM or UVB) 7-dehydrocholesterol in the epidermis is converted to vitamin D.

Detailed explanation-3: -The skin is responsible for producing vitamin D. During exposure to sunlight, ultraviolet radiation penetrates into the epidermis and photolyzes provitamin D3 to previtamin D3.

Detailed explanation-4: -In most people, UV rays activate a chemical in the skin called melanin. This is the skin’s first defense against the sun. Melanin absorbs the dangerous UV rays that can do serious skin damage.