MONDAY, March 5 (HealthDay News) -- Preteen and teenage girls
whose diets are rich in vitamin D may be at lower risk for stress
fractures, particularly if they are involved in high-impact
activities, according to a new study.
Researchers from Children's Hospital Boston followed over 6,700
girls, ranging in age from 9 to 15 at the start of the study, over
the course of seven years. The study, published in the March 5
online edition of the
Archives of Pediatrics & Adolescent Medicine, found nearly 4 percent of the girls developed a stress fracture during the follow-up period.
The investigators noted that vitamin D intake was associated
with a lower risk for stress fracture, and they found that this
link was stronger among girls who participated in at least one hour
of high-impact activity every day.
Although increased calcium intake is often recommended for
stronger bones, the study results indicated that dairy and calcium
may actually be unrelated to the development of stress
fractures.
"There was no evidence that calcium and dairy intakes were protective against developing a stress fracture or that soda intake was predictive of an increased risk of stress fracture," Kendrin Sonneville, of Children's Hospital Boston, and colleagues said in a journal news release.
The study authors said that their findings support the Institute
of Medicine's recent increase in the recommended dietary allowance
for vitamin D for teenagers to 600 international units (IU)
daily.
However, more research is needed to determine whether vitamin D
supplements provide the same benefits as vitamin D consumed through
diet alone, the team noted.
And while the study uncovered an association between vitamin D
intake and a lower risk of stress fractures, it did not prove a
cause-and-effect relationship.
Sources of vitamin D include being out in the sunlight and foods
including salmon, tuna, eggs and vitamin D-fortified milk.
More information
The U.S. National Institutes of Health's Office of Dietary
Supplements has more about
vitamin D.