I live in the Pacific Northwest - we get a lot of rain. I had vitamin D prescribed by a doctor years ago. I have asked around and everybody I asked whether they took vitamin D have said they do as it was prescribed by their doctor. So, I guess, up here most of us have been told to take our vitamins. This also, incidentally, includes Hispanics and Black folks too.
Kinda gives one a warm feeling of belonging to the same group of Vitamin D users.