What race gets skin cancer more frequently than other races and what race gets osteoporosis more than other races and why is this for each ailment?

Caucasian = melanoma. For melanoma, caucasians are most at risk due to their pale skin complexion. Also, the ozone layer is getting thinner at extreme southern and northern latitudes and letting more uv rays in which contribute to melanoma. For osteoporosis, the answer is not so clear. Race is not as important as socioeconomic status and nutrition. Osteoporosis is prevented by good calcium and vitamin d intake.
Skin cancer white. Skin cancer is definitely related to pigment. The whiter you are the more skin cancer. So it is very uncommon in africans and their descendants (except nonpigmented areas like the palms), more common in hispanics and mediterraneans, and most common in caucasians. It relates to the amount of normal maelanocytes in the skin which serve as somewhat of a sun protectant.