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Nutrition
What girls need to know about bone health
Why should I be worried about bone health now?
What is osteoporosis?
What is bone-strengthening activity?
How do calcium and physical activity make bones stronger?
How much calcium do I need? Does this mean I have to drink a lot of milk?
Should I take a calcium supplement (pill or powder) to make sure I get enough?
Can you get too much calcium?
Can I get enough calcium if milk upsets my stomach?
Are dairy products fattening?
I've heard that soda is bad for my bones. Why?
What else can I do to improve my bone health?
How can girls take part in bone-strengthening activity while staying indoors?
What kinds of bone-strengthening activity can girls with physical disabilities do to keep their bones strong?
For more information…
Why should I be worried about bone health now? 
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It is never too early to start worrying about bone health. Your peak bone-making years are in your childhood and teen years. If you do not make enough bone as a kid, your risk for a bone disease called osteoporosis goes up. And, while not common, a young woman can get osteoporosis. Having good eating and exercise habits now will help you to have strong, healthy bones throughout your life. A poor diet and not enough physical activity as a teen can cause you to have weaker bones as an adult. This not only makes it easier to get osteoporosis, it can hurt the body's ability to heal right after an injury. Getting enough calcium and vitamin D and doing enough of the right type of physical activity (called "bone-strengthening activity") can help protect your bones.
What is osteoporosis? top
Osteoporosis (say: ah-stee-oh-per-oh-sis) is a disease that thins and weakens bones to the point where they break easily. Hip, spine (backbone) and wrist bones are often involved. It is called a "silent disease" because bone loss happens without much notice. Having a bone break easily or getting a little shorter is often the first sign of this disease. While osteoporosis can strike at any age, over half of all women over age 65 have it.
There are certain things that are linked to your chances of getting osteoporosis. These things are called risk factors. Some risk factors cannot be changed, while others can be changed.
Risk factors that CANNOT be changed include:
- Sex. Women are more likely to develop the disease than men are. Women have lighter, thinner bones to begin with and their bones become thinner quickly after menopause (when periods stop for good).
- Age. The longer you live, the greater your chances are of getting the disease. The amount of bone loss varies among women, and not all women get osteoporosis.
- Family history. This disease runs in families, which means your risk of getting it is greater if someone in your family has the disease.
- Body size. Women who are small-boned and thin have a higher risk than women who are larger-boned and weigh more. But, being heavy does not mean that you will not get this disease.
- Ethnicity. White and Asian women are at greater risk for this disease. Black and Hispanic women do get osteoporosis, though.
Risk factors that CAN be changed include:
- Diet. Getting enough calcium and vitamin D in your diet will help you to build and keep strong, healthy bones.
- Bone-strengthening activity. Exercise helps keep bones strong and healthy over your lifetime.
- Smoking. Smoking lowers the level of the hormone estrogen in your body, which can cause you to go through menopause earlier, boosting your risk for osteoporosis.
What is bone-strengthening activity? top
Bone-strengthening activity is any activity that produces a force on the bones and promotes bone growth and strength. Examples of bone-strengthening activities that you can do include walking, running, tennis, dancing, tae kwon do, hiking, hopscotch, and basketball.
Activities that are not bone-strengthening include riding a bike and swimming. But, these activities are good for overall health and can be mixed in with bone-strengthening activities.
How do calcium and physical activity make bones stronger? top
To make bones strong and to keep them strong, the body needs calcium, vitamin D, and physical activity.
- Calcium helps bones to grow right. When the body makes new bone tissue, it first lays down a framework of a protein called collagen. Then, calcium from the blood spreads throughout the collagen framework. The hard crystals of calcium attach to the bone structure. Calcium and collagen work together to make bones both strong and flexible.
Calcium is also needed for many other activities within the body such as neural communication (the way your nerves and brain send signals to each other) and heart and lung functions. If the body doesn't get enough calcium from foods and drinks, it takes it from bones, which can make them weaker. - Vitamin D helps the body use calcium. Your bones can’t do their job without vitamin D. Lots of foods have calcium, but vitamin D can be harder to find. You can get what you need for the day by drinking two glasses of fortified milk, and some cereals and yogurts are fortified with vitamin D as well.
- Physical activity helps bones become stronger and thicker, just as a muscle gets stronger and bigger the more you use it. Bones are living tissue. Bone-strengthening activity causes new bone tissue to form, making bones even stronger. It also makes muscles stronger, and muscles push and tug against bones to make them even stronger. Physical activity also makes you better coordinated, which can make you less likely to fall and break a bone.
How much calcium do I need? Does this mean I have to drink a lot of milk? top
Girls ages 9 - 18 should get 1300 milligrams of calcium per day. But, so many girls don’t get nearly enough calcium.
There are lots of ways to get calcium, including milk. Check out this chart to see the amount of calcium that is found in different foods and drinks. As you can see, there are lots of good tasting foods and drinks you can choose to make sure you get enough calcium. Just add it up to 1300 milligrams each day!
Getting 1300 milligrams of calcium just from food seems kind of hard. Should I take a calcium supplement (pill or powder) to make sure I get enough? top
You can get plenty of calcium from foods and drinks. It's found in a variety of good tasting foods like milk, yogurt, broccoli, and low-fat cheese. Many foods also have extra calcium added to them, like orange juice, milk, breakfast cereals, and soy drinks. Be sure to check food package labels to see if they have added calcium. Girls who have a milk allergy or other dietary limitations should ask their doctor about calcium supplements. But most girls can get enough calcium by eating the right types of foods.
Can you get too much calcium? top
While it is possible to get too much calcium, it is not likely for most girls. Even with all the products that have added calcium, many girls take in far less calcium each day than the 1300 milligrams they need.
Can I get enough calcium if milk upsets my stomach? top
Some girls get a stomachache or have gas after they have milk or other dairy products because of lactose intolerance. The good news is that there are milk and other dairy products that are specially made for people with lactose intolerance. Look for milks, cheeses, cottage cheese, and other dairy products that are labeled "lactose-free" or "lactose-reduced." These dairy products have just as much calcium as the regular products. There are also pills and drops that can make it easier for you to digest milk and dairy products. Talk to your doctor if you would like to try one. Other foods rich in calcium include canned salmon, broccoli, and leafy green vegetables. Some foods have added calcium, like orange juice and cereals. Remember to look for "calcium" on food labels. Here is a list of food sources of calcium.
Are dairy products fattening? top
There are many low-fat or fat-free milk products available. Also, there is the same amount of calcium in fat-free and low-fat milk. Dairy products are a very important part of a teen's diet. They provide calcium, vitamin D, and other nutrients that help prevent osteoporosis.
There are good non-dairy sources of calcium. But, dairy products offer the most calcium per serving. For example, one cup of fat-free or low-fat milk has about 300 milligrams of calcium. One cup of broccoli (cooked or fresh) has about 90 milligrams of calcium.
I've heard that soda pop is bad for my bones. Why? top
Research suggests that teen girls who drink a lot of soda pop, especially colas, have more bone fractures (breaks). One reason that soda pop may be bad for your bones is that if you drink a lot of it, you might not be drinking as much milk as you should. As a result, you're not getting all the calcium and vitamin D that you need for growing healthy bones. Another reason may be that colas contain a lot of phosphoric acid (foss-FOR-ihk ASS-ihd). Taking in a lot of phosphoric acid may cause your bones to lose calcium, making them weaker.
What else can I do to improve my bone health? top
Steer clear of alcohol and smoking, and make sure your diet is healthy overall. Smoking, drinking alcohol, and having eating disorders such as anorexia nervosa or bulimia can cause weaker bones. If you have any of these habits and would like to stop, ask an adult that you trust for help. It is best, though, to never start these dangerous behaviors.
My neighborhood is not very safe. How can girls take part in physical activity while staying indoors? top
There are plenty of indoor bone-strengthening exercises that you can do to get strong, healthy bones. Dancing, lifting hand-held weights (or soup cans), jogging in-place, and push-ups can be done both indoors and outdoors. Check out Best Bones Forever!™ for some great ideas and activities you can do indoors.
What kinds of bone-strengthening activities can girls with physical disabilities do to keep their bones strong? top
Examples of bone-strengthening exercises for girls with physical disabilities:
- Wheelchair aerobics combines upper body movements and stretches to improve flexibility. They are done in a seated position, often to music.
- Arm cycling (ergometry) is like bicycling, only it is done with the arms instead of the legs. A girl can use a stationary (non-moving) bike or arm-driven cycles made for outdoor use. Always wear a helmet when cycling outdoors.
- Wheeling involves moving a wheelchair forward, using the arms or legs, over an extended distance. This can be done inside or outside, using a regular wheelchair or a specialized sport wheelchair.
- Resistance training uses wide elastic bands. One end of a band is attached to a non-moving object, such as a doorknob or the leg of a bed or a heavy table, while the other end is held and stretched to exercise one part of the body at a time. Hand weights can also be used for this type of training.
- Some sports can be adapted for girls with physical disabilities, like wheelchair tennis and wheelchair basketball.
To learn more about bone health, check out... top
Why Milk Matters Now, For Children and Teens (PDF - 5MB)
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Content last updated September 22, 2009
