Why do some people not need vitamin D in their diets?

Answer 1

Vitamin D is produced in the body when you get direct sunlight on the skin. for those who are fare and risk a burn with much time outside at all, early morning sun does almost the same benefit with less harsh rays. (wish i knew the science behind this...)

Genes also dictate how much you get from the sunlight per amount of time, how much you need altogether, and your threshold for health problems if you are in deficiency.

Pay attention to your body, and even better, act on your intuition without over-thinking things.