What is osteoporosis?

In osteoporosis (say “os-tee-oh-por-oh-sis”), the inside of the bones becomes weak because of a loss of calcium. This is called losing bone mass. Bone weakness makes your bones more likely to break.

Osteoporosis is much more common in women than it is in men. This is because women have less bone mass than men, they tend to live longer and take in less calcium, and they need the female hormone estrogen to keep their bones strong. If men live long enough, they also are at risk of getting osteoporosis.

Once total bone mass has peaked in a person's late 20s or early 30s, he or she starts to lose bone mass. In women, the rate of bone loss speeds up after menopause, when estrogen levels go down. Because the ovaries make estrogen, bone loss also may occur if both ovaries are removed by surgery.

What are the signs of osteoporosis?

You may not know you have osteoporosis until you have serious signs. These signs include broken bones, low back pain, or a hunched back. You also may get shorter over time because osteoporosis can make the bones in your spine push together. These problems tend to occur after a lot of bone calcium has already been lost.

Am I at risk for osteoporosis?

Below is a list of things that put you at risk for osteoporosis. The more of these risk factors that apply to you, the higher your risk is. Talk to your family doctor about your risk factors.

• Menopause before age 48

• Surgery to remove ovaries before menopause

• Not getting enough calcium and vitamin D in your diet

• Not getting enough exercise

• Smoking

• Osteoporosis in your family• Alcohol abuse

• Thin body and small bone frame

• Fair skin (white or Asian race)

• Hyperthyroidism

• Long-term use of oral steroids

• Prior bone fracture as an adult

Should I have a bone density test?

Check with your doctor. Women generally should be screened for osteoporosis starting at age 65. If a woman has several risk factors for osteoporosis, her doctor may recommend starting screening earlier. Some men should be checked for osteoporosis. Screening is usually done with a bone density test called a DEXA (dual energy x-ray absorptiometry) scan, which takes a “picture” of the bones. The DEXA scan can show thinning of the bones (osteopenia) as well as osteoporosis.

How much calcium and vitamin D do I need to help keep my bones strong?

You need about 1,000 mg of calcium a day before menopause and after menopause if you are taking estrogen. You need about 1,500 mg of calcium a day after menopause if you are not taking estrogen.

Nonfat and low-fat dairy products are good sources of calcium. Other sources of calcium include dried beans, sardines, and broccoli, as well as juices and cereals that have added calcium.

Your doctor may suggest that you take calcium in the form of a pill if you are not getting enough in your diet. Read the label on the bottle carefully to see how much calcium is in each pill. Take your calcium pill at mealtime or with some milk.

Vitamin D helps the body absorb calcium. Vitamin D is made in your skin when you are in direct sunlight, and it is also in fortified milk, egg yolks, some fish and fish oils, and liver. Your body needs 400 to 800 IU of vitamin D per day. You may need to take a pill if you are not getting enough vitamin D in your diet or if you are not in the sun much.

What medicines are there for osteoporosis?

In addition to a eating a good diet, exercising, and quitting smoking if you are a smoker, there are several medicines your doctor can prescribe if your bone scan shows you have osteoporosis. These medicines include the following:

• Calcitonin. Calcitonin (some brand names: Calcimar, Miacalcin) is a hormone that helps prevent further bone loss and reduces the pain that some people have with osteoporosis.

• Alendronate and risedronate. Alendronate (brand name: Fosamax) and risedronate (brand name: Actonel) are not hormones, but they are used to reduce the risk of spine fractures by decreasing the rate of bone loss.

• Raloxifene. Raloxifene (brand name: Evista) is a medicine used to prevent and treat osteoporosis by increasing bone density. It is not a hormone, but it has some of the good effects of estrogen.

• Teriparatide. Teriparatide (brand name: Forteo) is a synthetic hormone taken by injection (a shot) once a day. It causes new bone growth.

What about hormone therapy?

Hormone therapy is another way to prevent osteoporosis or keep it from getting worse. In this kind of therapy, you take female hormones (estrogen and progestin) to stop the drop in these hormones that happens at menopause or after the ovaries are removed by surgery.

Estrogen keeps your bones from losing calcium, helps your bones stay strong, and helps prevent broken bones.

Taking estrogen also can help some of the symptoms of menopause, such as hot flashes and vaginal dryness. Some studies also have shown that hormone therapy may reduce your risk of getting certain types of cancer.

Risks of hormone therapy include heart disease, strokes, blood clots, and breast cancer. You need to discuss your health history and your family's health history with your doctor to decide whether your risks from osteoporosis outweigh the risks of hormone therapy.