If you're one of those northern European types who burns when they so much as look at the sky, then bad news — you may need to get more vitamin D then you can safely gather from the sun. Alternatively: good news! You don't need to go in the sun to get vitamin D anymore!
Scientists found that in order to get a level of vitamin D in our bodies that's healthy, people generally need to hit 12 hours per weekend in the sun — and even that isn't enough for pale people who are very sun sensitive. Unfortunately, most pale folk can't go out in the sun for any amount of time without sunscreen, which prevents you from absorbing vitamin D.
So what do you do to get your vitamin D? Supplements — by which I mean chewy vitamins for grownups.