Your Lovely Bones

By Barbara Paulsen

You think there's nothing you can do to prevent osteoporosis. But the truth is, no matter your age, you can make changes that stop the disease in its tracks. Fracture-proof your body with this three-part plan and testing advice to preventing osteoporosis.

Exercise
Just as muscles grow stronger the more you use them, a bone becomes denser when you place demands on it — certainly until your early 30s. The best bone-building exercise is resistance training — lifting free weights, using the resistance machines at the gym, even Pilates and yoga. But any kind of weight-bearing exercise — where your legs support your body — helps prevent osteoporosis (jogging and dancing count; swimming and stationary bicycling are not weight bearing and therefore are less helpful). And it's never too late to start, according to several studies. In one, postmenopausal women who lifted weights for 45 minutes twice a week for a year increased their bone mass by 1 percent, while the control group, which did no resistance training, lost 2 to 2.5 percent. Experts recommend doing weight-bearing exercise at least four times per week for 30 to 60 minutes and resistance training two or three times, long enough to work each muscle group.

Calcium
Every woman under 51 should be aiming for 1,000 milligrams of calcium a day. Raise that to 1,200 after menopause. Most women are falling short. To figure out how you're doing, add up the servings of yogurt, cheese, milk and calcium-fortified orange juice or cereal you tend to get every day. One serving is an average of 300 milligrams. Recently, there's been some controversy about whether or not dairy products are a good source of calcium. A few experts are arguing that these foods actually leach the mineral from your bones (they reason that the dairy proteins raise levels of sulfur-containing amino acids in your blood that the body then must neutralize with calcium it raids from your skeleton). But Robert Heaney, MD, of Creighton University in Omaha, one of the country's top calcium experts, says not to worry: He has analyzed scores of randomized studies showing that dairy foods help keep bones strong.

The advice about supplements can get as finicky as the mineral itself. Calcium isn't easily absorbed in large amounts, so it's best to break up your daily intake into two to three doses and to take it with meals, says Heaney. For the calcium to reach your bones, you need to make sure you're getting 200 international units (IU) of vitamin D a day if you are 50 or younger; 400 IU, ages 51 to 69; 600 IU, 70 and older. Your body probably produces enough of the vitamin if you simply step out into the sunlight every day. But you may need to take a D supplement if you're supervigilant about sunscreen or if you're African-American, since melanin acts as a shield. You may have heard that supplements with calcium citrate are absorbed more easily than the calcium carbonate found in antacids, but Heaney says the evidence for both is equally strong. And if you can't be bothered with rules, just down your daily quotient all at once. It's better than not taking any at all.