Comment by wrsh07

> considering Denmark doesn’t get a lot of sun

> As they stated, it is because the population of Denmark is very homogenous

If you know about vitamin D, you'll note that sun exposure is one of the primary reasons location matters for this study. It would be similarly relevant if they only studied students in Miami or southern California.

Essentially: sun exposure helps you create vitamin D, and so you shouldn't naively generalize this study to other lines of latitude