Each living bone in our body is essentially a bank of calcium and minerals. If neglected, our bones can easily lose these important components and fracture. As you age, your body's ability to absorb calcium from food is diminished and may cause your bones to weaken. No matter your age or gender, you can help shape your future bone health.

Your body starts to form most of its bone mass before you reach puberty, building 75 percent of the skeleton during adolescence. Women reach their peak bone mass by age 25 to 30, while men build bone until age 30 to 35. The amount of peak bone mass you reach depends mostly on the genes that you inherit at birth. After you reach your peak bone mass, bone density gradually decreases as calcium is withdrawn from your bones. You can take action, however, to slow the leaching of calcium and, in fact, strengthen your bones.

Osteoporosis is a condition characterized by low bone mass and structural deterioration of bone tissue, which leads to fragile bones and an increased susceptibility to fractures. This condition is a major public health threat for millions of Americans. In the United States, approximately 8 million women and 2 million men have osteoporosis, and millions more have low bone density. While osteoporosis often is thought of as an older person's condition, it can strike at any age.

Early detection is important in osteoporosis. You may be able to slow the condition if you are predisposed to it. If you find that you are at risk, discuss a prevention strategy with your health care provider. Here is a list of risk factors:

• Gender. Fractures from osteoporosis are about twice as common in women as in men. That's because women start out with lower bone mass and tend to live longer. They also experience a sudden drop in estrogen at menopause that accelerates bone loss. The hormones estrogen and testosterone hold the balance between bone renewal and deterioration. Men who have low testosterone levels are also at an increased risk.
• Age. As you age, your risk increases.
• Race. Those who are white and are of Southeast Asian descent are at greatest risk. African Americans have the lowest risk, and Hispanics and Native Americans appear to have an intermediate risk.
• Family history. If your mother or sister has osteoporosis, you are at greater risk.
• Smoking. Research has shown that tobacco use contributes to weak bones.
• Certain medications. Long-term use of corticosteroid medications such as prednisone and cortisone - both of which are common treatments for chronic conditions such as asthma and rheumatoid arthritis - are damaging to bone.
• Hyperthyroidism. Also known as an overactive thyroid, this condition has been known to increase bone loss.
• An unexplained break. If you are older than age 50 and have experienced a bone fracture as the result of a seemingly minor injury, you may be at risk. Talk to your provider about a bone mineral density test.

The two key factors in preventing osteoporosis are building strong bones and preventing bone loss. By taking proactive steps throughout your life, you can help prevent the gradual bone loss that can lead to osteoporosis.

• Get your calcium. Maintaining healthy bones through a diet rich in calcium - an essential mineral that gives bones their strength - is critical for building peak bone mass now, and preventing bone loss later in life. Because your bones are living tissue, calcium is deposited and withdrawn from your skeleton constantly. If you don't consume enough calcium, or if it is not absorbed, more calcium is then withdrawn from your bones, resulting in fragile, porous bones. Calcium-rich foods include low-fat milk or yogurt, cheese, salmon (cooked, with bones), tofu, almonds, and dark green vegetables such as broccoli and turnip greens. If you don't drink milk, you can meet your calcium needs by choosing calcium-fortified foods such as orange juice, breads and breakfast cereals, or calcium supplements.
• Connect with vitamin D. Vitamin D helps your body absorb calcium and is found in fortified milk and egg products.
• Weight-bearing exercise. Jumping activities, jogging and walking provide the high-impact stress on which bones thrive. Resistance exercises such as weight lifting also build bone density in your legs, hips and lower spine. Talk to your doctor before starting new exercises.
• Avoid excessive alcohol. Consuming more than two drinks a day may decrease bone formation and reduce your body's ability to absorb calcium.
• Limit caffeine and soda. Caffeine can reduce your absorption of calcium. Diet sodas are high in phosphorus, which can cause an imbalance and loss of calcium in the body.
• Lower the protein in your diet. Similar to diet sodas, protein is high in phosphorus and can cause a loss of calcium.

Thanks to better diagnostic tools, you don't have to wait for a fracture to learn about your risk for osteoporosis and bone loss. The most accurate tool for diagnosing brittle bones is called a bone mineral density test, which uses sophisticated X-rays or sonograms to read your bone density. Osteoporosis experts recommend the following people receive a bone density test:

• Men and women who have a family history of hip or spine fractures, and who have had an unexplained fracture after age 50.
• Postmenopausal women with one or more risk factors listed above, who are not currently taking estrogen and weigh less than 127 pounds.
• Postmenopausal women who have type 1 diabetes, or liver or kidney disease.
• Men who are taking corticosteroid medications.

Approximately 80 percent of low bone mass and osteoporosis is undiagnosed, so be proactive and talk to your health care provider if you believe you're at risk. The good news about osteoporosis and bone loss is that it's never too late to take preventive measures.