Great question.

Traditional diets contained more vit D than what is orovided by the sun beating on bare skin. Its in liver. Remember when we used to eat the whole hog?? Been many generations since that happened in my family tree. Mom did make us take a spoonful of cod liver yuck. Lol Most people are indoors now, no sun there.

Dr Davis confirmed my thoughts on linking high vit D and low skin cancer rates. It is preventative. Doesnt cover the effects of severe burning of the skin as in sunburn.

My mother developed melanoma cancer late in life, and then breast cancer twice. Wish she had the calcium test to see how clean her arteries are likeky to be.....though her super exposure to uv was in the first half of her life, not the last half.