US Pharm.
2008;33(9):13-18.
With the aging of the baby
boomers, osteoporosis is looming as a major national epidemic. Many boomers
have already been diagnosed with the condition, and millions of others have
osteoporosis but are unaware of its presence. For this reason, the pharmacist
must be acutely aware of this condition and be ready to recommend calcium
products that might help prevent further bone loss.
Prevalence of Osteoporosis
At least 200
million women around the world are afflicted with osteoporosis.1
Osteoporosis is thought to affect 8 million women and 2 million men in the
United States.2-4 Low density of the bone at the hip is a problem
for another 21.8 million.2 Osteopenia is a state of low bone mass
that precedes full-blown osteoporosis, affecting approximately 34 million
additional Americans.3,4 Experts estimate that osteoporosis and
care of the fractures it causes are responsible for costs of $14 to $17
billion each year.1,4 The direct costs are projected to reach $50
billion by 2040, surpassing those for such conditions as stroke, breast
cancer, diabetes, and chronic lung disease.1
Epidemiology of Osteoporosis
While osteoporosis
can strike at virtually any age, there is a strong association with advancing
age, as bone becomes weaker and thinner with age.4 Patients over
the age of 50 years have a 55% risk of osteoporosis.2 There is a
sharp gender difference. Sixty-eight percent of those at risk are females, who
have a higher risk than males due to menopausal changes (i.e., low estrogen
levels).4 Males with decreased testosterone levels are at higher
risk. Body size also plays a role; those most at risk are small women with
thin bones.4 Those of Caucasian or Asian ethnicity are at higher
risk than those of African American and Hispanic background. Cigarette smoking
damages the bones and lowers estrogen levels, contributing to osteoporosis.5
Other risk factors include sedentary lifestyle and confinement to bed for long
periods, family history, excessive use of alcohol, and poor supplementation
with calcium and vitamin D.6
Osteoporosis in Males
Many males assume
incorrectly that men do not suffer from osteoporosis. Those who become
sufficiently concerned to see their physicians may be mistakenly reassured
that the problem is mostly seen in females, and so they may be denied a bone
mineral density test. It is unfortunate that, for these and other reasons, the
diagnosis in males is usually not made until a hip or spinal fracture occurs.7
Understanding the risk factors for osteoporosis in males can confer a greater
understanding of its significance. Some males develop osteopenia and
osteoporosis due to an age-related decrease in testosterone (i.e.,
hypoandrogenemia).4,7 Physicians can prescribe testosterone gel,
patches, tablets, injections, or buccal systems to help correct this problem.
Manifestations of
Osteoporosis
The major
consequence of osteoporosis is fracture, as fragile bone is particularly
subject to osteoporotic breaks. The incidence of osteoporotic fracture also
serves as an indirect mea sure of the incidence of osteoporosis. Osteoporosis
is responsible for causing a total of 1.5 million fractures yearly in
Americans, including 700,000 vertebral fractures, 250,000 fractures of the
wrist, and 300,000 hip fractures.4 Females aged 50 years have a 50%
risk of sustaining an osteoporosis-induced fracture.8 Males of the
same age have a 20% to 25% risk.4,8
Experts predict that the
incidence of hip fracture will mushroom to 6.3 million yearly in 2050.1
Hip fractures constitute a significant risk to health and independence.
Patients who experience hip fracture have a 20% risk of death within six to 12
months.1,8 Those who survive nonetheless endure the psychological
and financial burden of hospitalization, surgery, and rehabilitation. Further,
hip fracture leads to permanent institutionalization, permanent disability,
and loss of independence for as many as one-third of patients.8
Less than one-third of patients who endure hip fracture will ever return to
the full level of functioning they enjoyed prior to the incident.1
Assessing Osteoporosis
Osteoporosis is
assessed via bone mineral density tests of the hip, spine, wrist, finger,
shin, or heel.9 The hip dual-energy x-ray absorptiometry (DXA or
DEXA) exam yields a T-score, comparing the individual's bone mineral density
to that of a 30-year-old healthy adult with optimal scores.1,2 If
the T-score is -1 or less, the patient has a normal bone mineral density. If
the T-score falls in the range of -1.0 to -2.5, the patient has low bone
mineral density, or osteopenia. If the T-score falls below -2.5, the patient
is diagnosed with full osteoporosis.
Calcium Supplements
Calcium is critical
in preventing osteoporosis. Prospective, controlled trials have demonstrated
that administration of calcium reduces bone loss due to aging by as much as
50%.8 Unfortunately, the average American female takes in only 600
mg of calcium daily, placing her at a high risk of osteoporosis.2
Large segments of the American population fail to take in adequate calcium. In
the age range 6 to 11 years, 44% of boys and 58% of girls fail to meet the
recommended intakes. The figures rise to 64% of boys and 87% of girls in the
ages 12 to 19, and reach 55% for men and 78% for women at ages 20 and above.9
The pharmacist can provide a
good deal of information about choosing an appropriate calcium supplement.
Calcium carbonate is the most common form of the element in commercially
available supplements (e.g., Caltrate, OsCal, Tums, Viactiv). The molecule
contains 40% elemental calcium. An alternative is calcium citrate (e.g.,
Citracal), which is 21% calcium. The optimal recommended intakes of calcium
for different demographic groups are provided in Recommended Calcium
Intakes.
Coral calcium is promoted with
outlandish claims for treatment and prevention of serious medical conditions,
such as cancer, lupus, multiple sclerosis, and heart disease, on the basis of
a purported claim of increased bioavailability. In 2003, the FDA and Federal
Trade Commission (FTC) charged the marketers of Coral Calcium Supreme and
other operators with making these false and unsubstantiated claims.10
One would think that combined FDA/FTC action would stop further scamming.
However, a close examination of several Web sites reveals a fount of
misinformation hawked to gullible consumers by the same unscrupulous marketers
that were the subject of the 2003 FDA/FTC charges.11,12 Typical
statements made by the nonphysician scammers include the false assertion that
cancer is caused by a lack of free oxygen in the body, a "fact" unknown to the
real medical profession.12
Vitamin D
Vitamin D is
essential in absorbing calcium from the gastrointestinal (GI) tract and
ensuring bone health.2 Those aged 19 to 50 years should take in 200
IU daily, those aged 51 to 70 require 400 IU daily, and those 71 and older
should ingest 600 IU daily.5 Some experts believe that higher
intakes (800-1,000 IU) would further reduce the risk of fracture in older
patients.2 Patients who do not get adequate exposure to sunlight
would be well-advised to increase their vitamin D intake to 700 to 800 mg per
day.
Patients should be cautioned
not to ingest excess vitamin D. Most calcium supplements also include vitamin
D. Many patients also take a daily multivitamin. The pharmacist can obtain
bottles of both products when making a recommendation and point out the
amounts of vitamin D the patient ingests daily. If the amounts are clearly in
excess of the figures given above, the patient may be at risk of
hypervitaminosis D. This is more common in patients who have heeded incorrect
advice and ingest excessive vitamins each day.
Adverse Effects of Calcium
Supplementation
Excessive calcium
intake is not without adverse effects. Calcium carbonate requires an acidic
environment for absorption, and should be taken with meals, a possible barrier
to compliance. Many patients discover that calcium carbonate causes such
problems as flatulence and bloating because the pH interaction between acidic
gastric contents and the higher pH calcium compound produces gas, the same
type of gas one sees when mixing sodium bicarbonate and vinegar.
On the other hand,
water-soluble calcium citrate is a more attractive option for several reasons.
Calcium citrate can be taken without regard to meals, does not require the
acidic environment for absorption, and does not cause flatulence or bloating.9,13
Calcium citrate is also preferable in patents with decreased stomach acid,
whether it is their normal condition or a result of taking H2-blockers
(e.g., Pepcid AC, Zantac, Tagamet, Axid) or proton pump inhibitors (e.g.,
Aciphex, Nexium, Prevacid, Protonix).13
Calcium supplements can also
cause constipation. Patients should be advised to begin a regimen of increased
fiber and fluid intake to help offset the problem. Pharmacists can advise
three daily doses of psyllium or methylcellulose with the suggested amount of
fluid and also stress the healthy benefits of increasing fluid intake at other
times. Calcium citrate may produce less constipation.13
Kidney stones are a possible
adverse event.2 They are a known problem with calcium carbonate.
However, there is some evidence to demonstrate that calcium citrate is far
less prone to produce stones, perhaps due to its water solubility.14,15
Maximizing Calcium
Absorption
The percentage of
calcium absorbed is inversely proportional to the total amount ingested.9
Thus, it is counterproductive for patients with spotty compliance to take
their total daily doses at one sitting. Absorption of calcium is optimal when
the patient takes divided doses, with single doses not exceeding 500 to 1,000
mg.2,9 Furthermore, plants often contain chemicals that hamper
calcium absorption from the GI tract by binding with it. One interacting
substance is oxalic acid, which is found in spinach, collard greens, sweet
potatoes, rhubarb, and beans.9 Another is phytic acid, which is
found in whole grain bread, beans, seeds, nuts, grains, and soy isolates.
Patients should be cautioned to take their calcium supplements at times other
than when ingesting these foods.
Other Interventions
Numerous additional
interventions for osteoporosis prevention and treatment are beyond the scope
of the pharmacist's role in self-care. They include weight-bearing exercise,
such as walking, aerobics, and resistance exercises.13 The regimen
for a specific patient is best controlled and monitored by a physical
therapist or physician.
REFERENCES
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Epidemiology, etiology, and diagnosis of osteoporosis. Am J Obstet Gynecol.
2006;194(suppl):S3-S11.
2. Levine JP.
Pharmacologic and nonpharmacologic management of osteoporosis. Clin
Cornerstone. 2006;8:40-53.
3. Gass M,
Dawson-Hughes B. Preventing osteoporosis-related fractures: an overview. Am
J Med. 2006;119(suppl 1):S3-S11.
4. Osteoporosis.
National Institute of Arthritis and Musculoskeletal and Skin Diseases.
www.niams.nih.gov/Health_Info/Bone/Osteoporosis/Default.asp. Accessed July 25,
2008.
5. Osteoporosis. U.S.
Department of Health and Human Services. www.4woman.gov/faq/osteopor.htm.
Accessed July 25, 2008.
6. Rivlin RS. Keeping
the young-elderly healthy: is it too late to improve our health through
nutrition? Am J Clin Nutr. 2007:86(suppl):1572S-1576S.
7. Wright VJ.
Osteoporosis in men. J Am Acad Orthop Surg. 2006;14:347-353.
8. Keen R.
Osteoporosis: strategies for prevention and treatment. Best Pract Res Clin
Rheumatol. 2007;21:109-122.
9. Dietary supplement
fact sheet: calcium. National Institutes of Health.
http://dietary-supplements.info.nih.gov/factsheets/calcium.asp. Accessed July
25, 2008.
10. FTC and FDA take
new actions in fight against deceptive marketing. Federal Trade Commission.
www.ftc.gov/opa/2003/06/trudeau.shtm. Accessed July 25, 2008.
11. Bob Barefoot's--Cure
America! www.robertbarefoot.com/t-CureAmerica.aspx. Accessed July 25, 2008.
12. Coral calcium and
disease. www.robertbarefoot.com/t-CoralCalciumDisease.aspx. Accessed July 25,
2008.
13. Mauck KF, Clarke
BL. Diagnosis, screening, prevention, and treatment of osteoporosis. Mayo
Clin Proc. 2006;81:662-672.
14. Sakhaee K, Baker S,
Zerwekh J, et al. Limited risk of kidney stone formation during long-term
calcium citrate supplementation in nonstone forming patients. J Urol.
1994;152:324-327.
15. Sakhaee K,
Poindexter JR, Griffith CS, Pak CY. Stone forming risk of calcium citrate
supplementation in healthy postmenopausal women. J Urol.
2004;172:958-961.
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