Bone Strength for Life

Your body is made up of more than 200 bones. Bones are important because they support your whole body and everything you do - from just standing to running, jumping, writing, and even playing the piano.

Bones are made up of collagen, a protein that helps support bones, and calcium phosphate, a mineral that makes bones hard. Bones are also made up of water, other minerals, and living cells that grow and change.

Bones are always growing and they are strongest by your 20s, which is why you have to work hard to build your bone strength now. How? By eating and drinking foods that have calcium and doing enough weight-bearing physical activity.

Weight-bearing activities like walking and playing soccer make your bones work against gravity, the force that helps pull us toward the ground. This activity makes muscles stronger.

With muscles pushing and pulling against bones, bones become stronger. Weight-bearing activity also sparks new bone tissue to form, making them stronger.

Some weight-bearing activities:

• Dancing
• Running
• Lifting weights
• Tennis
• Karate or tae kwon do
• Push-ups
• Jump rope
• Hopscotch
• Hiking

When your body makes new bone tissue, it starts with a framework of collagen. Small, hard calcium crystals from your blood then fill the nooks and crannies of your collagen framework. Together, calcium and collagen make bones strong and flexible. Calcium is important to other parts of your body, but it is especially important to your bones.

Talk to your parents about checking labels for calcium at the grocery store. Even though dairy products are the best source, there are also lots of other foods that have calcium, such as broccoli and beans.

Girls ages 9 - 18 should get 1300 milligrams of calcium per day. But, so many girls don’t get nearly enough calcium. Add it up to reach your daily goal of 1300mg each day!

There are lots of ways to get calcium, including milk. The chart below lists 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!

FOOD	PORTION SIZE	CALCIUM (Milligrams)*
Plain, fat-free yogurt	1 cup	450
Grilled cheese sandwich**	1 sandwich	371
American cheese	2 ounces	350
Ricotta cheese, part skim	½ cup	340
Fruit yogurt	1 cup	315
Milk (fat-free, low-fat, or whole)	1 cup	300
Orange juice with added calcium	1 cup	300
Soy beverage with added calcium	1 cup	250-300
Cheese pizza	1 slice	220
Cheddar cheese	1 ounce	204
Tofu (made with calcium)	½ cup (about five 1-inch cubes)	204
Macaroni and cheese	½ cup	180
Cottage Cheese	1 cup	138 mg
Frozen yogurt (fat-free or low-fat)	½ cup	105
Broccoli, cooked or fresh	1 cup	90
Ice cream	½ cup	84
Bok choy, cooked or fresh	½ cup	80
Almonds, dry roasted	1 ounce(About 20-25 almonds)	71
White bread	2 slices	70

* Amount of calcium depends on the ingredients of many foods.

** Using 2 slices of white bread, 1-½ ounces of cheese, and nonstick cooking spray.

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?

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, cereal and other types of bars, and soy drinks.

Be sure to check food package labels to see if they have added calcium. Girls who have allergies 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?

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?

Yes. Lactose intolerance means some girls get a stomachache or have gas after they have milk or other dairy products. 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 products that are made with the enzyme lactase, which helps people digest dairy.

You can also buy Lactaid pills to chew or swallow with the first bite of dairy, which also have lactase. There are also other foods that have calcium like broccoli, almonds, and foods that have added calcium like orange juice and cereals. Remember to look for "calcium" on food labels.

Are dairy products fattening?

There are many low-fat or non-fat milk products available. Also, there is the same amount of calcium in non-fat and low-fat milk. Dairy products are a very important part of 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 is bad for my bones. Why?

Many sodas, including colas, have caffeine – the same ingredient in coffee and tea. Caffeine itself does not seem to harm bone health. But, young girls often choose soft drinks with caffeine over milk and other drinks high in calcium.

If you drink sodas with caffeine and sugar, you will have less room for bone-healthy drinks like milk and drinks that have extra calcium added to them (milk, soy milk, orange juice).

Remember: To make sure your bones stay strong, you need to get plenty of calcium every day. Check food labels to see how much calcium there is, and do your best to choose foods that add up to 1300 milligrams every day.

More information on teen girl's bone health