I'm in the US in Washington state near the Canadian border. The weather here is gray and rainy most of the year(I don't live that far from where Twilight was set). The doctors here pretty much assume people don't have enough Vitamin D and routinely recommend about 4000 units for adults. You can ask for and get a vitamin D level test, but the insurance usually won't cover it unless you can document a good reason why. I had outright deficiency levels when I was first tested and it and the next one that showed I was above deficiency were covered.
The endocrinologist I was going to was pretty much on top of things and good at spotting problems. She had me taking vitamin D and Fish oil. She has since retired and I ended up with a family practicioner(MD) who I am utterly unimpressed by. We are currently having a disagreement as to where my thyroid levels should be and the Family practice doctor is completely ignoring what the endo recommended. I can't get into another endo because there is simply no space with the local ones without traveling the better part of a hundred miles.