The vast majority of people do not live that far north. People who do should be well aware they are, in fact, "a special case" for purposes of dealing with vitamin D deficiency.
https://engaging-data.com/population-latitude-longitude/
For the boat loads of people looking to nail me to the wall over my very mild and qualified statement, why don't y'all try to get creative and look up data on vitamin D deficiency in girls in Muslim countries and then come up with some way to imply I am a misogynist* or I am anti-Muslim or something as part of this really, truly ridiculous pile on of people acting like I've said something crazy.
* If you don't know, I am probably the highest ranked woman here. I mean, that never prevents people from assuming I'm some rapey, misogynistic man. But at least try a little harder and don't give me really low hanging fruit for rebutting your argument like "Actually, I am a woman." because that's so very tired for so many reasons.