There are many risk factors for osteoporosis - some that you can change and some that you can't.

The risk of osteoporosis for both men and women increases with age because your bones normally become thinner as you get older. The more risk factors you have, the greater your chances are of developing osteoporosis.

Risk factors you can't change include:

• Age. The older you are, the greater your risk of osteoporosis. That is because your bones get weaker and lose density as you age.  Also, calcium absorption becomes less efficient as you age.
• Gender. Women have a greater likelihood of developing osteoporosis than men. Women have less bone tissue and lose bone more rapidly than men because of the changes associated with menopause and lower estrogen levels. Also, women who no longer have menstrual periods - either because their ovaries are not working properly (such as when they are very underweight) or because their ovaries have been surgically removed - are more likely to develop the disease.
• Ethnicity. Caucasians and Asians are more likely to have osteoporosis than people from other backgrounds.
• Family history of osteoporosis. If your mother, father, or siblings have experienced broken bones from a minor injury, you are more likely to develop osteoporosis.
• Thin body build. Slender people are more likely to develop osteoporosis because they have less bone tissue and less fat than heavier people. Also, fat tissue stores estrogen, which helps protect women from osteoporosis.
• Medical conditions such as hyperthyroidism put you at greater risk for osteoporosis.

Risk factors you can control:

• Diet. A diet low in foods containing calcium, phosphorus, and vitamin D is bad for your bones. Some studies indicate that excessive soda intake also affects bone health.
• Smoking. Smokers are at higher risk for osteoporosis than non-smokers.
• Alcohol use. Consuming more than two drinks a day may increase your risk.
• Lack of exercise. Weight-bearing activities (walking, jogging, stair climbing, dancing, or lifting weights) keep bones strong and healthy by working them against gravity.
• Overuse of antacids that contain aluminum. These products remove phosphorus and calcium from your body and cause faster than normal bone thinning.
• Exposure to sun.  About 15 minutes of direct sun exposure daily to hands and face, or alternatively vitamin D supplementation, is good for bone health. Sunscreen blocks the effect of sun on vitamin D metabolism too.

Other risk factors may include:

• Certain medications. Using corticosteroids to treat conditions such as asthma and chronic obstructive pulmonary disease (COPD) for six months or longer can lead to steroid-induced osteoporosis.  
• Being inactive or bedridden for extended periods of time.
• Excessive dieting or eating disorders, such as anorexia. People with eating disorders usually have low body fat and low levels of estrogen, which increases their risk for osteoporosis.
• Being a female athlete. Female athletes are at risk for developing osteoporosis if they have infrequent menstrual cycles due to low body fat. This can lower estrogen production, which can eventually weaken bones.