Exercise Plus Calcium Citrate Provides New Path to Preventing Osteoporosis
AZ, 3 September 2003
study by an interdisciplinary team of researchers in the Departments
of Physiology and Nutritional Sciences at the University of Arizona
has uncovered that weight-bearing and resistance exercises combined
with calcium citrate supplementation over one year provided significant
improvement in bone mineral density (BMD) of postmenopausal women
at specific important skeletal sites.
detailed findings were released today in Osteoporosis International,
the premier clinical publication on the disease. Notably, this benefit
was found both in women not on hormone replacement therapy (HRT)
and in women on HRT.
good news is that this study has identified a powerful combination
of improved nutrition and increased physical activity that prevents
bone loss," said Timothy Lohman, PhD, professor of physiology at
the UA and principal investigator on the study. "The bottom line:
when combined with calcium citrate supplementation, weight-bearing
and resistance exercises offer a benefit in building bone mineral
density." (Mission Pharmacal supplied Citracal(R) calcium citrate
supplements for the study.)
co-investigator Lauve Metcalfe, director of Community Programs and
exercise interventionist, UA Department of Physiology, added, "The
study focused on a regimen of six specific exercises that help build
bone in the hip and spine-two key fracture sites."
UA investigators have developed a specific exercise regimen that
they consider most effective in building bone in typically vulnerable
areas. They suggest 20 to 25 minutes of resistance training (doing
two sets of six to eight repetitions) using these six exercises:
out the study regimen are 7 to 10 minutes of cardiovascular weight-bearing
activity, such as skipping, jogging, and jumping rope.
key to achieving the goal of improved bone health is in the intensity
of the weight-bearing workout and the level of the resistance training,
says Scott Going, PhD, associate professor, UA Department of Nutritional
Sciences, and a co-investigator, who helped design the weightlifting
program that progressively increases the pounds of weight lifted
throughout the year.
bone mineral density is extremely important in staving off osteoporosis,
the gradual loss of bone density from the skeleton that often results
in fractures of the hip, spine and wrist. Signs of advanced osteoporosis
include stooped posture, loss of height and bones that break easily.
osteoporosis often can be prevented through adequate calcium intake
and exercise throughout life, beginning in childhood when people
are young and healthy. Unfortunately, most fail to take those preventive
steps. According to the National Institute of Arthritis and Musculoskeletal
and Skin Diseases, osteoporosis is a major health risk for 28 million
Americans10 million individuals already have osteoporosis
and 18 million more have low bone mass, placing them at increased
risk for the disease.
constantly grows through a regular process of breaking down (resorption)
and renewing itself (formation) until peak bone mass (maximum bone
density and strength) is reached during a person's mid-20s. Typically,
from that point on, bone loss outpaces formation. If left untreated,
osteoporosis can occur. Osteoporosis is more likely to develop if
optimal bone mass is not reached during the bone building years
from childhood to the mid-20s.
study developed a model for good bone health that was applied both
to women already on HRT and women not on HRT. For many years, experts
believed that the best way for postmenopausal women to increase
or maintain bone density was to go on HRT. While the effect of HRT
on bone health is well established, recent independent studies revealed
a growing list of side effects from this treatment, challenging
some of the major benefits of HRT and leading many women to re-evaluate
whether this therapy is right for them. The researchers in this
study, funded by the National Institute of Arthritis and Musculoskeletal
and Skin Diseases of the National Institutes of Health (NIH), found
that weight-bearing and resistance exercises plus adequate calcium
intake from food and calcium citrate were effective in improving
bone density in women not on HRT as well as in women on HRT.
foods such as milk, yogurt, kale, broccoli, cooked dried beans and
some cheeses are primary sources of calcium, most individuals do
not eat enough of these foods to get the amount of calcium needed
in their diets. To address this problem, the researchers supplemented
the study participants' diets with calcium citrate to help bridge
the gap between the amount of calcium in their diets and the amount
of calcium recommended by nutritional experts. The specific form
used was Citracal(R), supplied by Mission Pharmacal.
this study, the women were getting less than 800 mg of calcium per
day in their diet, and taking the calcium supplements ensured a
more optimal calcium intake," said Linda Houtkooper, PhD, professor
and head, UA Department of Nutritional Sciences, and a co-investigator.
the right amount of calcium is important at every age and doctors
often recommend supplements to ensure adequate intake. Three primary
kinds of calcium supplements are available: calcium citrate, calcium
carbonate and calcium phosphate. Even with a supplement, vitamin
D is necessary for the absorption of calcium into the bones. The
sun triggers the production of vitamin D in the body; however many
people, especially older persons, do not receive adequate sun exposure.
A diet rich in foods fortified with vitamin D, such as milk, will
help those who avoid the sun ensure better calcium absorption.
best treatment for osteoporosis is prevention. With weight-bearing
activities and strength-training exercises, tailored to strengthen
bone loss-vulnerable sites in the body, and regular adequate calcium
intake, postmenopausal women have a way to fight the chronic disease
of osteoporosis. Women of all ages should be concerned about their
bone health and take steps today to stay active and improve muscle
and bone strength.
University of Arizona Health Sciences Center.