Given the terrible health consequences of deficiency, I think assuming racial difference in healthy vitamin D levels is a more dangerous claim that requires a burden of proof.

Melanin absorbs the UV light our bodies use to produce vitamin D.

It is an important public health issue for people with darker skin living in temperate or polar areas to get enough vitamin D.

Lack of vitamin D for people with darker skin is the inverse of paler people being at risk of burns in sunny areas.