As mentioned right off the bat, the reason that white people are light is to absorb as much sunshine as possible to synthesize vitamin D.

THe other side of this coin is that dark people are EXTREMELY deficient in vitamin D at northern latitudes. NIH studies suggest that much of the reason for nearly double the heart problems among dark people is due to insufficient vitamin D.

I have witnessed black children in my area with rickets. This is inexcusable in a civilized nation.

We can make as much as 24,000 international units of Vitamin D from a coule hours of sunshine. The suggested daily requirment of 400 int. units of vitamin D per day is arguably wrong. Unlike vitamin A it is nearly impossible to get too much D.