Could you tell me what are good sources of vitamin d?

Sun.: All vitamin d is added to products such as milk. It is usually d3, which is inactive until turned into 25-oh d by the liver and finally 1, 25-dihydroxy-d by the kidney, otherwise called calcitriol. That being said, i believe this: i believe everyone should take at least 2000iu of d3 per day. It is not true that 15 min of sun will give us all we need.