As a redhead, this seems like a very big difference. I'm genetically way more likely to get cancer from sunlight than a non-redhead but also produce more vitamin d with less sunlight.
there is a school of thought that the vast majority of skin cancers are basically harmless (squamous cell and basal cell carcinomas), and that perhaps even the more of these carcinomas you have, the more sunlight you have received and so therefore the more vitamin D, and that you will therefore be healthier than someone without those carcinoma...restated, the more skin cancers you have, the healthier you are, in general...
