No, fair skinned people in equatorial regions don’t suffer from excessive vitamin D production. They suffer from chronic sunburns and the various ailments resulting from that...eventually cancer.
There are exceptions to the fair skinned people dominating the northern latitudes rule of thumb. I’d have to check to make sure, but I think people that hunt whale get plenty of vitD from their food. So lighter skin wouldn’t give them any benefit.
You have to remember that in colder climates, people wear lots of clothes. They must absorb all their sun light through their faces. So there are two things happening. Less skin exposed to sunlight, and less sunlight. Also, forests and climate probably play a role. People that live in heavily forested regions are going to get less sunlight. People that live in cold forests where fog and mist is common and the nights are long in the winter are really going to get limited sunlight.
Well, vitamin D was mentioned in the argument and sunburns/cancer weren't.