Blame too much television, over-liberal SPF-lathering, poor nutritional habits, and video games for a rise in cases of the bone disease rickets, say a pair of Newcastle-based UK researchers.
Rickets, in case you've only glancingly heard of it, describes a bone-softening disease that tends to occur in children and can cause fractures or lead to physical deformity. Lack of vitamin D tends to be the chief culprit, though insufficient calcium can play a role. It thus tends to strike children in developing countries most frequently.
Not anymore, it seems.
According to a British Medical Journal clinical review paper by Professor Simon Pearce and Dr Tim Cheetham, over half the adult population in the United Kingdom doesn't get enough vitamin D, with 16 percent of that population experiencing severe deficiencies during winter and springmonths, when the daylight hours are fewest.
I've been living in the UK since late 2008. The daylight thing's no joke.
Trace a line on a global map, latitudinally, and US readers may be surprised to find that even the southernmost parts of the UK share latitude lines with Canada. London, which sits at 51 degrees north, is at roughly the same latitude as Calgary, Alberta - over 100 miles north of US-Canadian border near Montana.
Point is, it gets dark pretty early here during the winter/spring months. Around Winter Solstice in December, the shortest day of the year, the sun clocks out already by 3:30 in the afternoon. In central Iowa where I used to live, by comparison, it's not down until 4:45pm - over an hour later.
So kids in school during the weekdays don't get much of a window after classes let out to soak up sun rays. What's more, this team of British researchers alleges, that's in part the fault of video games, which increasingly occupy what little time's left.
"Vitamin D levels in parts of the population are precarious," said Pearce. "The average worker nowadays is in a call centre, not out in the field. People tend to stay at home rather than going outside to kick a ball around. They stay at home on computer games."
It's not just a UK issue, either. I did a little quick research and discovered the following abstract from a paper published in a 2003 installment of Nutrition Reviews.
Several recent studies have identified a surprisingly high prevalence of vitamin D insufficiency i otherwise healthy adults living in Canada and the United States. Most striking are the effects of latitude, season, and race. Also noteworthy is that dietary vitamin D is not reaching the population in greatest need, nor is it very protective against insufficiency. Fluid milk, as the predominant vehicle for vitamin D fortification, is apparently not very effective in staving off vitamin D insufficiency in adults in all populations at all times of the year.
The solution? Short of sticking your kids under tanning lamps, it might be time to start adding vitamin D supplements to milk and other food, say Pearce and Cheetham.
"A more robust approach to statutory food supplementation with vitamin D (for example in milk) is needed in the UK," concludes the paper.
That, or you could just knock a hole in your roof (homebrew skylight!) and assume the position for, according to the researchers, "20 to 30 minutes of exposure to the sun two to three times a week."