There’s some surprising news for those of us who thought that ensuring the inclusion of calcium alone in the diet of our growing girls was enough for them to grow healthy bones.
Studies have been conducted at the Children's Hospital Boston to study the relation between occurrence of stress fractures in active adolescent girls, and their intake of dairy products and the findings tell a different story.
Stress fractures may occur when a bone or set of bones are overused or suffer repeated strain or load over a period of time.
Though not complete fractures, stress fractures can occur when muscles become fatigued, and in the absence of adequate rest are unable to absorb the shock of impact or load and transfer some of the shock to the bone or skeletal structure in question.
These are common injuries seen in activities such as tennis, squash, basketball, or any other form of high impact sport on hard surfaces. (1)
The study which was named "The Growing Up Today Study" examined 6712 pre-adolescent girls between 9 and 15 years of age.
It was found that Vitamin D was the critical mineral, and not calcium or dairy products, that bore a direct relationship to occurrence of stress fractures in those girls who were active and were involved in some sort of high impact sport (2)
The study included a seven-year followup of the children examined and found that approximately 3.9 percent of the girls developed a stress fracture, despite adequate intakes of calcium and dairy-rich products through their diet.
This clearly showed that either of the two factors were unrelated to the risk.
It was also observed that such girls who were involved in at least one hour of high-impact physical activity every day showed a change in the occurrence of stress fractures with a corresponding change in vitamin D levels in their diet.