A number of factors appear to play a role in determining who will develop the condition. The Osteoporosis Society of Canada has identified major and minor risk factors that indicate a person may be at risk and should be assessed for osteoporosis.

Major risk factors:

• Fracture with minimal trauma after age 40
• Family history of osteoporotic fracture (especially if your mother had a hip fracture)
• Long-term (over three months) therapy with a glucocorticoid (a group of anti-inflammatory compounds used widely to treat conditions such as rheumatoid arthritis)
• Having a medical condition that affects the absorption of nutrients (such as celiac disease or Crohn’s disease)
• Primary hyperparathyroidism (overproduction of parathyroid hormone)
• Tendency to fall
• Osteopenia (decreased bone density but not enough to be classified as osteoporosis) apparent on x-ray
• Hypogonadism (low testosterone in men or loss of menstrual periods in young women)
• Early menopause (before age 45)

Minor risk factors:

• Rheumatoid arthritis
• Hyperthyroidism (overactive thyroid gland)
• Prolonged use of anticonvulsants or heparin
• Body weight less than 57 kg (125 lbs.)
• Present weight more than 10% below weight at age 25
• Low calcium intake
• Excess caffeine consumption (consistently more than 4 cups daily of coffee, tea, cola)
• Excess alcohol consumption (consistently more than 2 drinks daily)
• Smoking

The risk factors are additive, so the more of them you have, the greater your chance of developing osteoporosis. Because the condition does not produce any symptoms until the bones are already so brittle that they break easily, everyone over age 65 and anyone over 50 who has at least one of the major risk factors or at least two of the minor risk factors should talk to their doctor about being tested for osteoporosis.

The primary method of identifying osteoporosis is by testing bone mineral density (BMD). The procedure is easy and painless, and repeat testing over time can track the rate at which bone density is lost. The test that is considered most accurate is dual energy x-ray absorptiometry (also known as DEXA or DXA).

There is another test that is sometimes used to screen people who may require further testing. This alternative test uses ultrasound waves passed through the heel. It is fast, easy, and painless, but it is not as accurate as the DEXA test.

One of the most important ways of reducing the amount of bone material we lose is to get all the nutrients necessary to keep our bones strong and healthy. The most important of these nutrients are calcium and vitamin D. Calcium is a primary building block of bone, and the body needs vitamin D in order to be able to absorb calcium.

The Osteoporosis Society offers the following guidelines for daily intake.

Calcium:

• Children age 4 – 8: 800 mg
• Adolescents age 9 – 18: 1300 mg
• Adults age 19 – 50: 1000 mg
• Adults over age 50: 1500 mg
• Pregnant and lactating women age 18 and over: 1000 mg

Vitamin D:

• Adults age 19 – 50: 400 IU
• Adults over age 50: 800 IU
• Pregnant and lactating women age 18 and over: 400 IU

Good food sources of calcium include dairy products (including lower-fat and non-fat varieties), sardines with the bones in, calcium-fortified orange juice, and tofu. Good food sources of vitamin D include fish liver oils and many types of fish, especially tuna, sardines, mackerel, and salmon. Perhaps the best source of vitamin D is exposure to sunlight, because the sun’s UV rays trigger the skin to make vitamin D. However, the benefits of getting vitamin D from the sun have to be weighed against the dangers of sun exposure.