In our health-conscious postmodern society, why are children breaking their arms more often? Why are they developing rickets, the 19th century “soft bone” disease? And why might they be at greater risk of osteoporosis than our own parents and grandparents?

The answer: a lack of this critical bone-friendly trio: sunlight, calcium, and exercise.

Almost half of peak bone mass develops during adolescence, and the concern is that missing out on the strongest possible bones in childhood could haunt people decades later. By the 30s, bone is broken down faster than it’s rebuilt. Then it’s a race to maintain bone and avoid the thin bones of osteoporosis in old age.

“There’s some early data showing that even a 10 percent deficit in your bone mass when you finish your adolescent years can increase your potential risk of having osteoporosis and fractures as much as 50 percent,” says Dr. James Beaty, president of the American Academy of Orthopaedic Surgeons.

Less than 25% of all adolescents get the recommended amount of calcium.

I thought that calcium was the most important factor by far in bone density and bone growth, but I was wrong: Strong bones require more than calcium alone. Exercise is at least as important. Consider: The dominant arm of a tennis player has 35 percent more bone than the non-dominant arm.

We already know that our children get less exercise than kids in generations past. But what does sunlight have to do with it?

Vitamin D (which the body absorbs from sunlight) is crucial to calcium absorption. If kids aren’t getting outside often, their bodies probably aren’t getting enough vitamin D, which in turn ratchets down how much calcium their bodies are absorbing.

It sounds to me like the best remedy for this disturbing trend is to get outside with the kids, have some good old-fashioned winter fun, and then come in for hot chocolate made with vitamin D-fortified milk. I can handle that!

Posted by Sunshine.