Your information is interesting, but until I see a better source for medical information than a moron statistician linking to web sited, I'll stay with the status quo. No wait, it's all a big conspiracy isn't it? The sunscreen companies are in cahoots with the makers of anti-cancer drugs and the medical profession as a whole.
As was pointed out, the levels of D are probably way below what one receives on snow or water, and areas such as the nose or hands are at risk for skin cancer. that is why the medical profession makes use of statisticians who are not morons