Get the Scoop on Calcium

When you're young, you often don't worry about what will happen in your fifties, sixties and beyond. Those years - and the threat of osteoporosis - seem a lifetime away.

The truth, though, is that bone health is important at all ages. Bone is dynamic tissue. It breaks down and builds back up. The calcium you take in is absorbed into your bones, where it provides structural support. Bone also stores calcium for use throughout the body. When your body needs calcium, it "steals" it from your bones for nerve cell conduction, muscle contraction and other vital functions. Calcium from your diet goes back to replenish bone.

You build most of your bone mass before your teen years. Between the ages of 12 and 18, girls reach 42 percent of their total bone mass. Both men and women build peak bone mass by age 20. After that, bone is not replaced as readily. If you don't replenish that calcium regularly, especially as you get older, your bones can become thin, brittle and weak. By following good nutrition, exercise and lifestyle practices throughout your life, good bone health will be a natural result. Nutritionally, you need two things for healthy bones: calcium and vitamin D.

How much calcium do I need a day?

The National Academy of Sciences recommends:

• 500 mg (1 to 3 years)
• 800 mg (4 to 8 years)
• 1,300 mg (9 to 18 years)
• 1,000 mg (19 to 50 years)
• 1,200 mg (51 + years)

What are sources of calcium?

Nonfat or low-fat dairy products are good sources of calcium. According to the U.S. Department of Agriculture, everyone over 2 years of age should have three cups of dairy products daily. A cup is equal to any of the following:

• 1 cup (8 fluid ounces) of milk
• 8 oz. of yogurt
• 1 1/2 oz. of natural cheese (such as Cheddar)
• 2 oz. of processed cheese (such as American)

Nondairy foods that are high in calcium include Chinese cabbage, kale, sardines and broccoli. You can also buy calcium-fortified juices and cereals. Calcium is also sold as a supplement. Check with your doctor before you add calcium supplements to your diet.

What is the role of vitamin D?

Without enough vitamin D, the body can't absorb and deposit calcium into the bones. The human body makes its own vitamin D when radiation from the sun interacts with a chemical in the skin. But sunlight isn't enough. The Institute of Medicine makes the following recommendations for daily vitamin D intake:

• Adults ages 19 to 50 need 200 IU (international units)
• Adults ages 51 to 70 need 400 IU
• People older than 70 need 600 IU

The National Osteoporosis Foundation recommends an even higher daily amount of vitamin D:

• Adults under 50 need 400 to 800 IU
• Adults age 50 and older need 800 to 1,000 IU

You find vitamin D in:

• Fatty fish such as salmon (750 IU/3 oz.), mackerel (380 IU/3 oz.) and tuna (150 IU/3 oz.)
• Fortified foods (look for the word "fortified"), including milk, yogurt and some orange juice and breakfast cereals
• Supplements, such as vitamin D products alone, multivitamins or calcium supplements with added vitamin D

Be sure not to go over the recommended daily amount. Too much vitamin D can be toxic.

How to get more calcium

There are ways to raise your calcium level without taking a supplement. To start, be sure to get plenty of vitamin D in your diet. You need it to absorb calcium. In addition:

• Don't take in all of your calcium in one meal. Your body can't absorb more than 500 mg of calcium at a time
• Substitute low-fat milk instead of water in recipes for pancakes, puddings, mashed potatoes or instant cereals
• Sprinkle grated low-fat cheese on salads or pasta dishes
• Create a fruit smoothie with low-fat or fat-free yogurt
• Serve a yogurt-based dip with raw fruits and vegetables
• Avoid foods that interfere with calcium absorption:
• Limit your intake of heavily salted foods, such as bacon, salami, smoked salmon, prepared soups and salty snacks. Consume fewer than 4,000 mg of sodium per day. Alcohol and caffeine also interfere with calcium absorption.
• Don't combine wheat bran with calcium-rich foods and supplements. While 100 percent wheat bran provides good nutrition and fiber, it interferes with the absorption of calcium in other foods when eaten at the same time. If you have wheat bran in the morning, take your calcium supplement at least two hours afterward.