Vitamin D: Any of a group of fat-soluble alcohols important in calcium metabolism in animals to form strong Bones and teeth and prevent rickets and osteoporosis. It is formed by ultraviolet radiation (sunlight) of sterols present in the skin.

• 维生素D: 一类脂溶性醇(麦角固醇、胆利钙醇、导钙素)的统称,在动物体内钙的代谢中具有重要功能,能使骨骼和牙齿健壮,并预防佝偻病和骨质疏松。在人体中,维生素D由阳光照射皮肤中的固醇而形成。