PITTSBURGH — All over the world, millions of people see skin color as a symbol of superiority or inferiority, whether they are conscious of it or not.
Others see humanity’s array of skin tones, from white to ocher to black, as a positive mark of our remarkable diversity.
But Nina Jablonski sees skin color, first and foremost, as an evolutionary gateway to vitamin D.
Jablonski, the Evan Pugh professor of anthropology at Penn State University, has made a name for herself with her research on how human skin color evolved from the earliest humans to today’s multiple hues. The short version: Our skin color is primarily designed to regulate how much sunlight we let into our bodies to produce vitamin D, which is important for bone health, safe pregnancies and a strong immune system. In a related way, it also keeps too much ultraviolet radiation from destroying folate in women’s bodies, which can lead to certain birth defects.