Milk and other calcium-rich foods have always been a must-have in kids' diets. After all, calcium is a key building block for strong, healthy bones. But most kids ages 9 to 18 don't get the recommended 1,300 milligrams of calcium per day.

That's not surprising when you consider that many kids now drink more soda than milk, which is one of the best sources of calcium. And teens who smoke or drink soda, caffeinated beverages, or alcohol may get even less calcium because those substances interfere with the way the body absorbs and uses calcium.

But at every age, from infancy to adolescence, calcium is one nutrient that kids simply can't afford to skip.

What Calcium Does

During childhood and adolescence, the body uses the mineral calcium to build strong bones — a process that's all but complete by the end of the teen years. Bone calcium begins to decrease in young adulthood and progressive loss of bone occurs as we age, particularly in women.

Teens, especially girls, whose diets don't provide the nutrients to build bones to their maximum potential are at greater risk of developing the bone disease osteoporosis, which increases the risk of fractures from weakened bones.

Younger kids and babies with little calcium and vitamin D intake (which aids in calcium absorption) are at increased risk for rickets. Rickets is a bone-softening disease that causes severe bowing of the legs, poor growth, and sometimes muscle pain and weakness.

Calcium plays an important role in muscle contraction, transmitting messages through the nerves, and the release of hormones. If blood calcium levels are low (due to poor calcium intake), calcium is taken from the bones to ensure normal cell function.

When kids get enough calcium and physical activity during childhood and the teen years, they can start out their adult lives with the strongest bones possible. For optimal bone health, the Institute of Medicine (IOM) recommends:

• 1 to 3 years old — 700 milligrams of calcium daily
• 4 to 8 years old — 1000 milligrams
• 9 to 18 years old — 1,300 milligrams

Getting enough calcium is just part of the equation. Kids from 1 to 18 years old also should get 600 IU of vitamin D daily. If you don't think your kids are getting the nutrients needed, talk to your doctor about modifying their diet or using vitamin supplements.

Good Sources of Calcium

Of course, milk and other dairy products are good sources of calcium, and most contain added vitamin D, which is also important for bone health.

But don't overlook the many other healthy calcium-fortified foods, including orange juice, soy products, and bread. Here are some dairy and nondairy products that provide quite a bit of this vital nutrient:

Minding Your Milk

Milk and other dairy products are among the best and most convenient sources of calcium you can find. But just who should get what kind of milk and when?

• Infants under 1 year old shouldn't have regular cow's milk because it doesn't have the nutrients a growing baby needs. Stick with breast milk or infant formula as your baby's major source of nutrition during the first year.
• Kids between 1 and 2 years old should have whole milk to help provide the dietary fats they need for normal growth and brain development.
• After age 2, most kids can switch to low-fat or nonfat milk.

The good news is that all milk — from skim to whole — contains about the same amount of calcium per serving. The 2010 Dietary Guidelines recommend 2 cups (473 milliliters) of milk per day for kids 2 to 3 years, 2½ cups for kids 4 to 8 years (354 milliliters), and 3 cups (710 milliliters) for kids 9 years and older.

When Kids Can't — or Won't — Eat Dairy

Some kids can't or won't consume dairy products. Here are some ways to make sure they get enough calcium:

Kids with lactose intolerance: Kids with lactose intolerance don't have enough of the intestinal enzyme (lactase) that helps digest the sugar (lactose) in dairy products. These kids may have cramps or diarrhea after drinking milk or eating dairy products.

Fortunately, low-lactose and lactose-free dairy products are available, as are lactase drops that can be added to dairy products. Also ask your doctor about tablets that kids with lactose intolerance can take that allow them to eat dairy products and thus benefit from the calcium they contain. Hard, aged cheeses (such as cheddar) are also lower in lactose, and yogurts that contain active cultures are easier to digest and much less likely to cause lactose problems.

Kids with milk allergy: The proteins in milk might cause allergic reactions in some people. Casein is the principal protein in cow's milk, accounting for about 80% of the total milk proteins. Casein is what makes up the curd that forms when milk is left to sour. The remaining 20% of cow's milk proteins are contained in the whey, the watery part that's left after the curd is removed. Someone may be allergic to proteins in either the casein or the whey parts of milk and sometimes even to both.

Talk to your doctor if you think your child may be allergic to milk. Formula-fed infants with a cow's milk allergy may need to be switched to soy-based or hypoallergenic formula. For older kids, good alternatives to milk and milk products include calcium-enriched rice or soy milk (if soy is tolerated), vegan products (such as vegan cheese), and other soy-based (again, if soy is tolerated) or rice-based frozen desserts, sorbets, puddings, and ice pops.

Vegetarian kids: Parents of kids who are ovo-vegetarians (they eat eggs, but no dairy products) or vegans (they eat only foods from plant sources) may be concerned about whether a dairy-free diet can supply enough calcium.

Although it can be more of a challenge to get the recommended amounts of calcium in a vegetables-only diet, good sources of calcium include dark green leafy vegetables, broccoli, chickpeas, and calcium-fortified products, including orange juice, soy and rice drinks, and cereals.

Teens who think dairy products are fattening: Adolescent girls, in particular, may decide to diet and avoid eating dairy foods they think will make them fat. But it's important for your teen to understand that an 8-ounce (240-milliliter) glass of skim milk has only 80 calories and zero fat and supplies one quarter of a teen girl's recommended daily calcium intake.

In fact, people who eat diets rich in calcium may actually weigh less and have less body fat. In one study, adolescent girls who had an extra 300 milligrams of calcium each day, which is equivalent to one glass of milk, weighed up to 2 pounds (907 grams) less than girls who didn't get the extra calcium.

You can also offer low-fat and nonfat dairy products as healthy alternatives to whole milk products — and instead of sodas and sugary fruit drinks that have very little nutritional value. If your teen drinks juice, offer calcium-fortified 100% fruit juices (not too much juice, though, as that can contribute a lot of sugar and calories).

Also talk to your teen about osteoporosis and the importance of dairy products and other calcium-rich foods in a healthy diet.

Kicking Up the Calcium

Of course, some picky eaters just don't like the idea of dairy products. To make sure they get enough calcium, try these creative tactics.

Add cheese to meals and snacks:

• Put some cheddar in an omelet.
• Add a slice of American, Swiss, or provolone to sandwiches.
• Use whole-grain soft-taco shells or tortillas to make burritos or wraps. Fill them with eggs and cheese for breakfast; turkey, cheese, lettuce, tomato, and light dressing for lunch; and beans, salsa, taco sauce, and cheese for dinner.
• Create mini-pizzas by topping whole-wheat English muffins or bagels with pizza sauce, low-fat mozzarella cheese, and toppings like mushrooms, green peppers, tomatoes, or chunks of grilled chicken.
• Serve whole-grain crackers with low-fat cheese as an afternoon treat.
• Make grilled cheese sandwiches or piece of cheese appealing by using cookie cutters to create hearts, stars, and favorite animal shapes.
• Top vegetables (especially those that usually prompt an "Ick!" or an "Ew!") with melted low-fat cheese.

Put some pizzazz in regular milk by adding a touch of strawberry or chocolate syrup (which doesn't add a significant amount of sugar or calories). Steer clear of store-bought flavored milk drinks, though, which can be packed with unnecessary sugar.

For breakfast, add fresh fruit or unsweetened apple butter to cottage cheese or yogurt.

For dessert or an afternoon snack:

• Serve low-fat or fat-free frozen yogurt topped with fruit.
• Create parfaits with layers of plain yogurt, fruit, and whole-grain cereal.
• Give kids a glass of ice-cold milk to wash down a couple of favorite cookies or graham crackers.

Serve nondairy foods that still pack a calcium punch:

• Add white beans to favorite soups.
• Top salads or cereals with slivered almonds and chickpeas.
• Serve chili with red beans and cheese.
• Pour a tall glass of calcium-fortified juice for breakfast.
• On grocery-shopping excursions, look for calcium-fortified foods, including breads and cereals.
• Serve more dark green leafy vegetables (such as broccoli, kale, collard greens, or Chinese cabbage) with meals.

Caring About Calcium

Although it's best for kids to get the calcium they need through a calcium-rich diet, sometimes it's not possible. Discuss calcium supplements with your doctor if you're concerned that your kids aren't getting enough calcium.

Vitamin D is essential for calcium absorption, so it's important that kids have enough of this nutrient too. Made by the body when the skin is exposed to sunlight, vitamin D also is found in fortified foods, fish, and egg yolks.

Also, don't forget to motivate kids to be involved in regular physical activities and exercise, which are very important to bone health. Weight-bearing exercises such as jumping rope, running, and walking can also help develop and maintain strong bones.

Most of all, act as a role model and consume low-fat dairy products and other calcium-rich foods — you could probably use the calcium, too!

Reviewed by: Mary L. Gavin, MD
Date reviewed: September 2011