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The effects of excessive UV exposure are known; the effects of UV deficiency are ...

• axaxs 6y ago
  Not a scientist...but strongly feel humans would not have diverged into different skin colors if UV deficiency weren't a fairly large issue.
  • nomel 6y ago
    Perhaps not: https://www.ucsf.edu/news/2016/06/403401/darker-skin-stronger-skin-says-new-view-human-skin-color https://www.ucsf.edu/news/2016/06/403401/darker-skin-stronge... I would assume that looking for UV deficiency related statistics would be trivial with dark skinned people living in a European country.
    • axaxs 6y ago
      Interesting, thanks. When I made that statement I thought to myself the only other reason that makes sense would be if pigmentation was somehow expensive, which is what the article concludes if I understand correctly - "a pigmented skin barrier, which is metabolically expensive to produce, became less important" As for the latter comment, I've read numerous times that black adults in the US have lower vitamin d levels. I guess back to the GP's point, is there proof that is a detrimental thing?