Episode 32 Human skin can make large amounts of vitamin D when lots of skin is exposed and the sun is high in the sky. Your body is designed to get the vitamin D it needs by producing it when your bare skin is exposed to sunlight. The part of the sun's rays that is important is ultraviolet B (UVB). Send your answer [email protected] or. https://instagram.com/fastedhuman and available Facebook.com/FastedHuman