I found this entry on andrewcoyne.com (columnist for the National Post) about sunblock rather interesting:

Take off the sunscreen
Classic. Decades of scare stories about the sun’s evil rays, years of alarmist warnings by politicians and others (“for God’s sake keep your kids out of the sun”), and what do we find is the major cause of cancer in northern countries? Lack of sunshine...:

For decades, researchers have puzzled over why rich northern countries have cancer rates many times higher than those in developing countries — and many have laid the blame on dangerous pollutants spewed out by industry.

But research into vitamin D is suggesting both a plausible answer to this medical puzzle and a heretical notion: that cancers and other disorders in rich countries aren’t caused mainly by pollutants but by a vitamin deficiency known to be less acute or even non-existent in poor nations…

For many reasons, Canadians are among the people most at risk of not having enough vitamin D. This is due to a quirk of geography, to modern lifestyles and to the country’s health authorities, who have unwittingly, if with the best of intentions, played a role in creating the vitamin deficiency…

Only brief full-body exposures to bright summer sunshine — of 10 or 15 minutes a day — are needed to make high amounts of the vitamin. But most authorities, including Health Canada, have urged a total avoidance of strong sunlight or, alternatively, heavy use of sunscreen. Both recommendations will block almost all vitamin D synthesis.

Ok, so this is a blog entry about a blog entry about a news article, but I can’t help wondering what else the scientific community and governments might be wrong about that are driving policy and public education…