Osteoporosis: Prevention in Teen Years (cont.)
Eat Your Way to Strong Bones
The main mineral in bones is calcium, one of whose functions is to add strength and stiffness to bones, which they need to support the body. To lengthen long bones during growth, the body builds a scaffold of protein and fills this in with calcium-rich mineral. From the time you're 11 until you're 24, you need about 1,200 milligrams (mg) of calcium each day. Adolescent bodies are tailor-made to "bone up" on calcium. Calvo says that with the start of puberty, "your body is at a higher capacity to absorb and retain calcium." Bone also needs vitamin D, to move calcium from the intestine to the bloodstream and into bone. You can get vitamin D from short, normal day-to-day exposure of your arms and legs to sun and from foods fortified with the vitamin. Also needed are vitamin A, vitamin C, magnesium and zinc, as well as protein for the growing bone scaffold. Mother Nature provides many foods with these nutrients. One stands out, however, as "almost a perfect package," according to Calvo. "Milk is rich in calcium and high-quality protein. Nearly all U.S. milk has vitamins D and A added. And it has magnesium and zinc." Still, as excellent as milk is for bones, it and other dairy products are not the only foods that contain calcium. All groups in the Food Guide Pyramid, in fact, offer calcium sources -- from the pyramid's grain-based foods that you need the most of, to the produce and high-protein groups in the middle, and even to the fats and sweets "use sparingly" group at the top. The importance of choosing calcium sources from the different food groups is that each group offers its unique package of other nutrients as well.
To learn how much calcium is in a food, you can read the food label's Nutrition Facts panel. Look for the "percent Daily Value" (%DV) set by FDA for calcium. The calcium DV is 1,000 mg. But if you are 11 to 24 years old, your growing bones need more -- the recommended 1,200 mg. So, each day's calcium %DVs in the foods you eat should add up to 120 percent. Because many foods are now fortified with calcium, your investigation of labels may turn up surprising sources. To identify foods with at least 10%DV of calcium per serving, FDA allows these terms on their labels:
An easy daily plan is to drink a calcium source at every meal and eat one calcium food as a snack, says Ruth Welch, a registered dietitian with FDA. If the lactose sugar in dairy products causes problems like gas, bloating or diarrhea, try lactose-reduced or lactose-free milk. When fortified, these products can have up to 50%DV for calcium in one serving. Also available are lactase drops and tablets, which can help you digest dairy products like ice milk, yogurt, and cheese.