With regard to sunbathing in Sweden, it sounds like the study was originally designed to track many variables for possible influence on blood clots. Tanning behavior ended up having a high correlation with lower all-cause mortality. I haven't looked into whether they controlled for variables like socioeconomic situations that allow for more suntanning, though that seems likely before publishing such a conclusion. What seems less likely to have been controlled when just looking for contributors to blood clots, would have been whether the subjects' skin tanned easily.
Many light-skinned people do not easily tan at all, and even complain that their skin seems to go straight from white to red. In Sweden, there are many people who do tan easily in spite of having very light skin. It seems like that could very easily have been a confounding factor. The genes that make you bun easily or tan easily seem like they would have a significant effect on ones decision on whether to sunbathe or not. Likewise, I can imagine that those genes could also affect all-death mortality rates.
personally I used to burn pretty easily (light skin, freckles) When I was much younger and spent most my time indoors. However I took up multiple outdoor activities and after quite some time in the sun it’s rare for me to burn even after hours in the sun with no sunscreen, and if I do burn it heals fairly rapidly.
So outside genes there may be some sort of adaptation going on.
True. Another thing to consider is that regardless of the health effects, sun exposure ages your skin; sometimes dramatically so.
A compromise would be to use sunscreen on your face and neck (since they don't produce that much vitamin D anyway, if I'm remembering a study correctly), but leave the rest of your body uncovered. Perhaps add sunscreen to your hands too.
Many light-skinned people do not easily tan at all, and even complain that their skin seems to go straight from white to red. In Sweden, there are many people who do tan easily in spite of having very light skin. It seems like that could very easily have been a confounding factor. The genes that make you bun easily or tan easily seem like they would have a significant effect on ones decision on whether to sunbathe or not. Likewise, I can imagine that those genes could also affect all-death mortality rates.