Umm you definitely get Vitamin D from sunlight. I don't know what you were reading. But it's wrong. Your stratum germativum and spinosum make cholecalciferol which is pre vitamin D, this comes from the sunlight. It then goes to the kidneys where it turns into calcitriol then in the liver it becomes calcium binding protein because in order for the body to absorb calcium it must make this complex from vitamin D which is absorbed from the sunlight. Vitamin D is put into milk for people who live in places that don't get much sunlight.