Osteoporosis, which means "porous bone," is a disease in which the bones gradually become weak and brittle. That often results in fractures -- especially of the hip, wrist, and spine -- even from simple activities like lifting a chair or bending over. According to the National Institutes of Health (NIH), about 10 million Americans have osteoporosis, while another 18 million have low bone mass and are at an increased risk for the disease. Osteoporosis is common among the elderly, but the disease can strike at any age. Although it is more common in older women, men can also have the disease.

Osteoporosis is a potentially crippling disease. The latest estimates from the NIH indicate that osteoporosis is responsible for more than 1.5 million fractures annually. Fortunately, most Americans can avoid osteoporosis altogether by eating well-balanced diet, exercising regularly, and living a healthy lifestyle.

Osteoporosis is sometimes considered a "silent disease" because bone loss can occur without symptoms. In fact, many people may not know they have the disease until they break a bone. Osteoporosis can also cause a vertebra (one of the 33 bony segments that form the spine) to collapse. Signs of a collapsed vertebra include:

• Back pain
• Loss of height
• Kyphosis -- curvature of the spine that causes a humplike deformity

How strong and dense your bones are results in part from the amount of calcium and other minerals they contain. Your body is constantly making new bone and breaking down (reabsorbing) old bone. When you are young, this process happens quickly, and you make more bone than you lose, so you build bone mass. After your mid-30s, your body continues to make new bone, but more slowly, so that you lose more bone than you make. The amount of bone you have in your 30s helps determine your risk of developing osteoporosis later. For women, bone loss increases significantly at menopause, when estrogen levels drop.

Other than age and menopause, causes of osteoporosis can include:

• Long-term use of certain medications, particularly corticosteroids and thyroid medications (see Warnings and Precautions section)
• Cushing's syndrome (when the adrenal glands produce too much of a hormone called cortisol)
• Kidney failure
• Diseases of the thyroid or adrenal glands
• Deficiencies in calcium, vitamin D, vitamin A, vitamin K, and magnesium (however, high intake of vitamin A may actually increase the risk of osteoporosis)
• Anorexia nervosa
• Alcoholism
• Rheumatoid arthritis

• Being female
• Being older -- after age 75, the risk is the same for men and women
• Being of European or Asian ancestry
• Living a sedentary lifestyle
• Being very thin
• Family history of osteoporosis
• Late onset of menstruation or early menopause
• Smoking cigarettes, drinking too much caffeine, or drinking alcohol regularly
• Diet low in calcium or high in sodium
• Long-term use of certain medications, including corticosteroids, diuretics, and thyroid medications
• Depression

Osteoporosis can be prevented. Because your body builds bone mass until you are in your 30s, prevention should start early. Making sure you get enough calcium and vitamin D (required for your body to use calcium) is essential.

Weight-bearing exercise, such as walking or lifting weights, as well as other exercises, including tai chi, can also help stave off the disease. Research has shown that exercise early in life boosts bone mass, while exercise later in life helps to maintain bone mass. Exercise also increases strength, coordination and balance -- important tools to help prevent falls that cause fractures, especially in the elderly.

Other techniques for prevention include:

• Adding soy to your diet.
• Quitting smoking.
• Limiting caffeine to about three cups of coffee a day.
• For women, hormone replacement therapy (hormone replacement therapy has significant side effects, including increased risk of breast cancer, blood clots, and heart disease).

If your doctor believes you are at risk for osteoporosis, the doctor often recommends a bone mineral density test (BMD) to determine your bone mass. This test is painless, noninvasive, and safe. It typically measures bone density in the spine, wrist, and hip (the most common sites of fractures due to osteoporosis), while others measure bone in the heel or hand.

The National Osteoporosis Foundation recommends a BMD for women who are not taking estrogen and:

• Use any medications that put you at risk for osteoporosis
• Had an early menopause
• Have a family history of osteoporosis, kidney disease, liver disease, or type 1 diabetes
• Are over 50, postmenopausal, with at least one risk factor for osteoporosis
• Are over 65 and have never had a BMD

For those who are at risk for osteoporosis or already have the disease, current treatments are designed to boost bone mass and prevent (further) bone loss. While calcium by itself doesn't cure or prevent osteoporosis, getting enough calcium is an essential part of any prevention or treatment program. Making lifestyle choices, such as consuming a diet rich in fruits and vegetables and participating in a weight-bearing exercise program can also enhance bone strength.

Lifestyle

Diet

Studies suggest that diets rich in the following foods and nutrients may help prevent bone loss in both men and women:

• Calcium -- Low-fat milk, cheese, and broccoli are rich in calcium. Orange juice and cereals often are fortified with calcium
• Magnesium -- Avocado, banana, cantaloupe, honeydew, lima beans, low-fat milk, nectarine, orange juice, potato, spinach
• Potassium -- Whole grains, nuts, spinach, oatmeal, potato, peanut butter
• Vitamin D -- The body makes vitamin D after exposure to sunlight. It is also found in fatty fish and fortified cereals and milk
• Vitamin K -- Leafy greens, cauliflower
• Fruits
• Vegetables

Exercise

Exercise can help prevent bone loss. Although it is helpful to begin exercising when you are young (to help build bone), it's never too late to get the benefit. Weight-bearing exercise (walking, weight-lifting) stimulates bones to produce more cells, slowing bone loss. Exercise also improves balance, flexibility, strength, and coordination -- thereby reducing falls and fractures associated with osteoporosis.

Drug Therapies

Although the standard treatment for osteoporosis for postmenopausal women used to be estrogen, there are new options for men and for women who are wary of estrogen's risks. Most medications slow down the rate at which bone is reabsorbed (antiresorptive). One new drug can actually help the body make new bone (bone forming).

• Estrogens (with or without progesterone) -- boosts bone density and reduces the risk of fracture by slowing bone loss, boosting the body's ability to absorb calcium, and reducing the amount of calcium excreted in the urine. Estrogen by itself can increase a woman's risk for developing cancer in her uterine lining (endometrial cancer), so many doctors have prescribed a combination of estrogen and progesterone. However, evidence now shows that this combination increases a woman's risk of breast cancer and heart disease. Talk with your doctor to get a clear understanding of the risks and benefits of taking estrogen.
• Alendronate (Fosamax), ibandronate (Boniva), and risedronate (Actonel) -- these medications belong to a class of drugs known as bisphosphonates. These drugs have been shown to boost bone density, slow or stop bone loss, and reduce the risk of fractures. Side effects are uncommon but may include abdominal pain and heartburn, which can be reduced by taking the medications with 8 oz. of water first thing in the morning before eating anything else, and standing upright for at least 30 minutes after taking them.
• Raloxifene (Evista) -- from a class of drugs called Selective Estrogen Receptor Modifiers (SERMS), raloxifene has estrogen-like effects on bone (it prevents bone loss) but does not increase the risk for breast cancer. Side effects can include hot flashes and blood clots. It should not be used before menopause.
• Calcitonin (Miacalcin) -- Does not improve bone density as well as the bisphosphonates, but it does slow bone loss, reduce spinal fractures, and ease pain associated with bone fractures. An alternative for women who cannot take estrogen or bisphosphonates.
• Parathyroid hormone (Forteo) -- used in low doses, this drug can increase bone production. It can only be taken by injection. It is often prescribed for postmenopausal women and men at risk of fracture. It should not be used in children.

Surgery and Other Procedures

A procedure called kyphoplasty can be used to treat kyphosis, the humplike deformity sometimes caused by osteoporosis. A catheter inserts a balloon into the middle of a collapsed vertebra and then expanded so that height of the vertebra is restored. The surgeon then injects bone cement into the vertebra to hold its shape.

Complementary and Alternative Therapies

Nutrition and Supplements

Eating fruits and vegetables and consuming adequate amounts of calcium and vitamin D are crucial in the prevention and treatment of osteoporosis. Keeping bones healthy throughout life depends on getting enough of specific vitamins and minerals, including phosphorous, magnesium, boron, manganese, copper, zinc, folate, and vitamins B12, B6, C, and K. Avoiding sodium, alcohol, and caffeine will also enhance bone health.

Calcium -- Calcium helps the body build bone. Recommended intakes of calcium are as follows (note that you generally get from 500 - 700 mg of calcium in your diet):

• Children: 800 - 1,200 mg/day
• Adolescent girls: 1,200 - 1,500 mg/day
• Premenopausal women (19 - 50 years old): 1,000 mg/day
• Older adults (51 - 70 years old): 1,200 - 1,500 mg/day

(Recommended intake for older women is 1,500 mg/day, except for those on estrogen, who need only 1,000 mg/day.)

Good dietary sources of calcium include:

• Low-fat dairy products (such as milk, yogurt, and cheese)
• Dark green, leafy vegetables (such as broccoli, collard greens, and spinach)
• Salmon
• Tofu
• Almonds

If you do not get enough calcium from food alone, you may want to take a calcium supplement. There are several different kinds available. Ask your doctor which one is right for you:

• Calcium citrate (Citrical, Solgar) -- Most easily absorbed; costs more
• Calcium carbonate (Tums, Caltrate, Rolaids) -- least expensive; must be taken with meals or a glass of orange (acidic) juice; may cause gas or constipation
• Calcium phosphate (Posture) -- Easily absorbed, does not cause stomach upset; more expensive than calcium carbonate

Calcium supplements should be taken in divided doses during the day, because your body can only absorb 500 mg or calcium at a time. Work with your doctor make sure you get enough, but not too much, calcium.

Vitamin D -- In order to absorb enough calcium, your body also needs vitamin D. Recommended intakes of vitamin D are as follows:

• Older adults (51 - 70 years old): 400 IU/day; (71 years and older): 600 IU/day

During the winter, or in the case of a bone fracture, 800 IU/day may be required. Doses greater than 1,000 IU can be dangerous.

Vitamin K (150 - 500 mcg) -- Vitamin K, which the body makes in the intestine, helps bind calcium into bone. A recent study suggests that at menopause, vitamin K may start to lose its ability to bind calcium, so that even women with normal levels of vitamin K may not have enough to maintain bone health. Eating three servings of low-fat dairy or dark, leafy greens per day can help. Talk to your doctor about whether you need a supplement, especially if you take blood-thinning medications (diuretics).

Soy isoflavones -- Isoflavones are phytoestrogens, plant chemicals that have some of the same effects as estrogen. Because estrogen helps protect against osteoporosis, researchers theorize that isoflavones may also help stop bone loss. Several studies seem to agree. The best source of soy isoflavones is through your diet (tofu, soy milk, soybeans); when isoflavones are consumed in foods, they don't appear to have the same negative effects that supplemental estrogen does. If you have a history of hormone-related cancer, talk to your doctor before taking soy.

Ipriflavone (600 mg per day) -- Ipriflavone, a synthetic isoflavone derived from natural isoflavones found in soy, red clover, and other food sources, may also help prevent and treat osteoporosis. Most studies -- though not all -- indicate that ipriflavone, when combined with calcium, can slow bone loss and help prevent fractures of the vertebrae (spine) in postmenopausal women. Talk to your doctor before taking ipriflavone.

Fish oil (4 g per day) -- A few studies have shown that supplements containing essential fatty acids, such as those found in fish oil, can help maintain or possibly increase bone mass. Essential fatty acids appear to increase the amount of calcium absorbed your body, diminish the amount of calcium lost in urine, improve bone strength, and enhance bone growth. Foods rich in essential fatty acids (including coldwater fish such as salmon) can help raise the amount of essential fatty acids in your diet. People who are taking blood-thinning medication (anticoagulants) should not take fish oil supplements without talking to their doctor first.

Preliminary studies also suggest that the following nutrients may help prevent or treat osteoporosis:

• Zinc -- stimulates bone formation and inhibits bone loss in animals.
• Vitamin C -- may limit bone loss in early years of menopause. Studies show mixed results.
• Melatonin -- melatonin is involved in bone growth. Since levels of melatonin drop as you age, it's possible that melatonin may contribute to the development of osteoporosis, but further studies are needed. People who take antidepressants or psychiatric medications should not take melatonin without a doctor's supervision.

See the Warnings and Precautions section for a list of supplements that people with osteoporosis should avoid.

Herbs

Although most herbs have not been studied extensively for the treatment of osteoporosis, some have estrogen-like effects that might offer similar protection against osteoporosis. However, they may also carry some of the same risks as supplemental estrogen. Talk to your doctor before taking any of these herbs.

• Black cohosh (Cimicifuga racemosa) -- contains phytoestrogens (estrogen-like substances that help protect against bone loss). It os often used to relieve menopausal symptoms, although evidence for its effectiveness is mixed. It does not appear to increase the risk of breast cancer the way supplemental estrogen does.
• Red clover (Trifolium pratense) -- isoflavones extracted from this herb may slow bone loss in women, but it is not clear whether the whole herb has similar effects. More tests are needed to prove its effectiveness.

Other herbs that may help prevent or treat osteoporosis (evidence is lacking so far) include:

• Horsetail (Equisetum arvense) -- contains silicon, believed to strengthen bone
• Kelp (Fucus vesiculosus L.) -- used for musculoskeletal disorders; rich in minerals so may be an effective complementary treatment for osteoporosis
• Oat straw (Avena sativa) -- boosts hormone levels that stimulate cell growth

Warnings and Precautions

Some studies suggest that too much vitamin A may increase the risk for osteoporosis. People with osteoporosis, or those at risk for it, should not exceed the daily recommended intake of vitamin A (900 mcg/day for men and 700 mcg/day for women).

Certain medications may contribute to the development of osteoporosis when used for long periods of time:

• Corticosteroids (steroid hormones)
• Thyroid medications
• Blood-thinners
• Diuretics (water pills)
• Antibiotics
• Immune system suppressants
• Aluminum-containing antacids

Talk to your doctor if you take any of these medications.

Prognosis and Complications

Bone fractures are the most common complications of osteoporosis and are a significant cause of disability and death. After age 60, 25% of women have a spinal fracture -- and that percentage doubles after age 75. By age 90, 33% of women and 17% of men have had a hip fracture, usually from a minor fall or accident. Many elderly people who suffer a hip fracture lose the ability to walk and, most significantly, up to 36% die within one year.

Although an estimated 1.5 million bone fractures in the U.S. each year result from osteoporosis, most of these fractures are preventable. Several medications are currently being researched that may expand the treatment options available to people with osteoporosis. In the meantime, a combination of medications, diet, exercise, and calcium and vitamin D supplements can help slow the progression of the disease.

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