Osteoporosis is a thinning of the bones the ultimate result of a slow, progressive loss of bone mineral that affects us all, beginning at around age 35. Although this process is most pronounced in postmenopausal women, osteoporosis can also affect men as they age. For people in their 80s, bone density may be reduced by 30% to 50%. About 24 million Americans have serious thinning of their bones, and osteoporosis is associated with 1.2 million bone fractures every year.
An important cause of osteoporosis is a lack of calcium early in life. Adults need 1,000 to 1,200 milligrams per day.
Good dietary sources of calcium include:
- Low-fat milk
- Orange juice with added calcium
Many doctors often suggest a 250 or 500 milligram supplement of calcium every day.
Vitamin D is just as important as calcium. Vitamin D is made in our skin when exposed to sunlight. However, most of us do not get enough sun exposure to make all the vitamin D we need. Adults should take a daily vitamin D supplement. The usual recommendation is 400 to 800 international units of vitamin D per day. Many specialists advise a higher dose of 1,000 IU daily.
Calcium absorption and excretion can be affected by what you eat. High-caffeine foods, such as coffee, tea and caffeinated sodas, may deplete the body's stores of calcium, and thus may promote bone loss. Diets high in protein and sodium also increase calcium excretion.
Evidence shows that regular aerobic and resistance exercise can also help maintain bone density at any age. A survey of 350 middle-aged women found that those who were most active in their daily lives had significantly greater bone density in their spines, hips and forearms than less active women. In general, aerobic activity seems to increase bone density by a few percent, provided the activity is weight-bearing (walking, running, dancing or aerobics classes, for example).
An additional bone-density boost can be obtained by doing regular resistance exercises, such as lifting weights, two or three times a week. Any activity that stresses bone stimulates bone formation, making bone stronger with time. Your bones can benefit from regular resistance exercise at any age. In fact, some elderly women actually increased their bone density through a program of regular exercise, combined with adequate intake of calcium and vitamin D.