FROM:
J Bone Miner Res 2008 (May); 23 (5): 741–749
Lappe J, Cullen D, Haynatzki G, Recker R, Ahlf R, Thompson K
Creighton University Osteoporosis Research Center, Omaha, Nebraska, USA
INTRODUCTION: Stress fractures (SFx) are one of the most common and debilitating overuse injuries seen in military recruits, and they are also problematic for nonmilitary athletic populations. The goal of this randomized double-blind, placebo-controlled study was to determine whether a calcium and vitamin D intervention could reduce the incidence of SFx in female recruits during basic training.
MATERIALS AND METHODS: We recruited 5201 female Navy recruit volunteers and randomized them to 2000 mg calcium and 800 IU vitamin D/d or placebo. SFx were ascertained when recruits reported to the Great Lakes clinic with symptoms. All SFx were confirmed with radiography or technetium scan according to the usual Navy protocol.
RESULTS: A total of 309 subjects were diagnosed with a SFx resulting in an incidence of 5.9% per 8 wk. Using intention-to-treat analysis by including all enrolled subjects, we found that the calcium and vitamin D group had a 20% lower incidence of SFx than the control group (5.3% versus 6.6%, respectively, p = 0.0026 for Fisher's exact test). The per protocol analysis, including only the 3700 recruits who completed the study, found a 21% lower incidence of fractures in the supplemented versus the control group (6.8% versus 8.6%, respectively, p = 0.02 for Fisher's exact test).
CONCLUSIONS: Generalizing the findings to the population of 14,416 women who entered basic training at the Great Lakes during the 24 mo of recruitment, calcium and vitamin D supplementation for the entire cohort would have prevented approximately 187 persons from fracturing. Such a decrease in SFx would be associated with a significant decrease in morbidity and financial costs.
Comments from Dr. Stephen Chaney, PhD
I constantly run into people who think that supplements
are just for the old and the sick.
These people say: "I'm young and healthy. Why should I
supplement?"
I came across a very interesting article that answers
that question.
This study showed that calcium and vitamin D
supplementation reduced the risk of stress fractures in
people who were very active.
Now you might be tempted to say "That's not news - but
doesn't that just apply to older people".
That's what made this article so interesting. This
study was performed on 5,201 female U.S. Navy recruits
- not exactly the geriatric set.
The women, ages 17 to 35, were divided into two groups
with one group receiving daily supplements containing
2,000 mg of calcium and 800 IU of vitamin D, and the
other group receiving placebo pills.
The study was conducted during eight weeks of basic
training from 2002 to 2006 at Great Lakes Naval Station
near Chicago, IL.
During the study, 170 recruits in the placebo group
experienced stress fractures, about 25 percent more
than in the group taking the calcium/vitamin D
supplements.
The scientists in charge of the study said "What really
surprised us is that calcium/vitamin D supplements made
a significant difference in such a short period of
time. Frankly, we were not sure we would see any
statistically significant results in only eight weeks."
The implications of this study are enormous.
Stress fractures are one of the most common and
debilitating overuse injuries seen in U.S. military
recruits in all branches of the Armed Forces. Estimates
are that as many as 21 percent of all female recruits
suffer this injury.
Stress fractures often lead to chronic pain and
disability. In addition, the cost of a single soldier
discharged from basic training is estimated to be
$34,000, not including expenses related to health care.
More importantly, the scientist running the study
pointed out that the same results would probably be
seen in anyone who was physically active at any age.
For example, the study may also have implications for
nonmilitary athletic populations, such as high school
track and field athletes, in whom stress fractures also
occur frequently.
The lead investigator concluded: "It appears that
supplementation with calcium and vitamin D provides a
health-promoting, easy and inexpensive intervention
that does not interfere with training goals."
So are you too young for supplementation? I don't think
so!
>
> Dr. Stephen Chaney, PhD
