What is Osteoporosis?

Osteoporosis literally means “porous bone.” Osteoporosis does not cause the outer form of the bones to change. However, the bones become less dense and more susceptible to fracture. A fall, blow, or lifting action can easily break one or more bones in someone with osteoporosis.

What Bones Are Most Commonly Affected by Osteoporosis?

The spine, wrist, and hip are the most common sites of osteoporosis-related fractures, although the disease can affect any bone of the body.

When the bones of the spinal column (the vertebrae) are weakened, a simple action, such as bending forward to make a bed or lifting a heavy roast pan out of the oven, can be enough to cause a crush fracture or spinal compression fracture. These vertebral crush fractures often cause back pain, decreased height, and a humped back (: dowager’s hump”).

Wrist fractures also occur commonly among people with osteoporosis. For example, an otherwise healthy, vigorous woman in 50′s or 60′s slips on ice, falls, reaches out to catch herself, and is taken to the emergency room with a broken wrist.

Osteoporosis is often the underlying cause of broken hips suffered by more that 200,000 Americans over age 45 each year. A fall from a standing position can fracture a hip weakened by osteoporosis. In cases of severe osteoporosis, a change of posture or weight distribution alone can actually break the hip, and the fracture will then cause a fall.

What is the Role of Calcium in the Development of Osteoporosis?

Living bone contains a protein framework in which calcium salts are deposited. In fact, the bones and teeth contain about 99 percent of the calcium in the body. Calcium makes bones hard.

Bone, like many other tissues of the body, is constantly being rebuilt or “remodeled”. Old bone is torn down, reabsorbed and replaced with new bone in much the same way that people remodel buildings by tearing out and replacing walls.

This process of bone reabsorbtion and remodeling serves two purposes; it keeps the skeleton well tuned for it’s mechanical uses, and it helps maintain the body’s balance of certain essential minerals, such as calcium. The body keeps a relatively constant level of calcium in the blood because important biologic activities, such as contraction of muscles, beating of the heart, and clotting of blood, require quite constant blood levels of calcium.

When the blood calcium level drops, more calcium is taken out of the bones to maintain the appropriate level, when the blood calcium level returns to normal, increased amounts of calcium are no longer taken from the bones.

As a person grows during youth, bones are metabolically active and calcium is deposited into bone faster than it is taken out. The deposition of calcium into bone peaks at about 35 years of age in men and women. At the time of peak bone mass, the bones are most dense and strong.

During a person’s late 30′s, calcium begins to be lost from bones faster that it is replaced and bones become less dense.

Nutrition Guidelines for Preventing Osteoporosis and Minimizing Bone Loss

A balanced diet with adequate calcium can help to avoid bone loss that occurs with age. Experts recommend 1,500 mg of calcium each day for women after menopause and 1,000 mg for younger women.

Foods high in calcium include milk and other dairy products; sardines; and salmon, canned with the bones; oysters; and dark-green leafy vegetables. Milk processed to be more digestible is available for those who have problems digesting milk; soy or acidophilus milk also can be used. In addition, calcium supplements, especially calcium carbonate, are frequently prescribed.

Getting enough vitamin D is also important because it is needed by the body to absorb calcium. The recommended dietary allowance (RDA) for vitamin D is 400 units (International Units) daily. Vitamin D is provided by such foods as fortified milk, egg yolk, liver, tuna, salmon, and cod liver oil.

Vitamin D is also produced in the body after exposure to sunlight. Only a short period of exposure each day is sufficient.

To further minimize bone loss, some doctors suggest that women eat less red meat and avoid certain carbonated soft drinks. These contain high levels of phosphorus (a mineral normally present in almost equal amounts in bone and teeth) and might contribute to a phosphorus-calcium imbalance that has been associated with osteoporosis.