Take a minute and give thanks to all the hundreds of thousands of scientists in the world who work, sometimes at relatively mediocre wages, trying to further our understanding of the world. Take Dr. Kendrin Sonneville and colleagues at Children’s Hospital in Boston who spent several years of their lives studying more than 6,000 girls, age 9-15, to see if they could, in part, unravel the mystery surrounding stress fractures.
For those who don’t know, stress fractures start with pain, usually in the foot, but without any apparent injury. You go to your doctor who does an x-ray and tells you that you have a “stress fracture.” You tell her that can’t be, you didn’t injure your foot, didn’t twist anything, it just hurts. You have been doing a little running, but generally, you’ve just been doing what most young girls do, how in the world did you break a bone? She just shrugs her shoulder and repeats “stress fracture.”
For reasons unknown, bones are sometimes just not strong enough to put up with every day wear and tear; a situation, when you think about it, which makes little sense. Our ancestors probably had to run for miles, many days, chasing game. However, Dr. Sonneville found that nearly 240 of the 6,000 young girls had stress fractures over the seven-year period of the study.
Why? You guessed it and it’s not calcium or dairy products. Only vitamin D showed an effect. The girls in the highest 1/5 of vitamin D intake (food and supplements) had 50% fewer stress fractures compared to the girls with the least vitamin D intake. In fact, higher calcium intake tended to be associated with more, not fewer, stress fractures, the first time scientists have reported such a finding. The other surprise was that not only was high calcium intake unlikely to prevent a stress fracture, sodas and pop did not increase the risk. The newspaper story below explains the study as well.
Roan S Vitamin D linked to stronger bones in girls. LA Times
I don’t know Dr. Sonneville but I wish I knew her, along with thousands of other scientists like her. While stress fractures may not seem important to some, they shatter many a hope.