Bone Density
It is never too late to start protecting your bones
Fact #1
Calcium, vitamin D and weight-bearing exercise are important for bone health.
Fact #2
The bones inside your body are living tissues. Healthy bone is flexible and strong.
Fact #3
Throughout your life you are constantly removing old bone and forming new bone.
Fact #4
Most bone mass is formed during the teens. Bones reach their maximum density and strength (bone mass) in early adulthood. By middle age, our bodies build up less bone to replace the loss of old bone.
Fact #5
In the first few years after menopause, women lose bone mass rapidly. Bone loss then slows down, and bone mass continues to decrease gradually.
If you are at risk of developing osteoporosis or think you may have low bone density, see your doctor.
Your doctor can assess your risk factors and may arrange bone density tests
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Osteoporosis
Osteoporosis
Osteoporosis is a health condition that occurs when your body is not forming enough new bone, or too much bone is lost, or both. When this happens, bones become more brittle and can fracture more easily. Osteoporosis develops gradually. It isn’t possible to feel your bones becoming thinner and weaker. Most symptoms of osteoporosis happen in later life. Many people only find out that they have osteoporosis after fracturing a bone (e.g. hip, spine or wrist) after a minor bump or fall. Fractures of the spine are often not diagnosed until some time later.
People with advanced osteoporosis can become shorter than they were when young and may develop a stooped or hunched-over posture and have problems moving around normally. Osteoporosis is diagnosed with a bone density scan. It can be treated with medicines.
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Risk factors for osteoporosis
Risk factors for osteoporosis
- Ageing
- Being female (especially post-menopausal)
- Family history of osteoporosis or fractures
- History of fractures as an adult
- Not enough calcium in the diet
- Not enough vitamin D
- Not enough physical activity
- Drinking too much alcohol
- Cigarette smoking
- Low body weight or excessive body weight
- Medical history
- Thyroid conditions (overactive thyroid gland or parathyroid gland)
- Delayed puberty and/or early menopause in women
- Low testosterone in men
- Coeliac disease
- Inflammatory bowel disease
- Eating disorders
- Rheumatoid arthritis
- Some medicines (e.g. cancer medicines, epilepsy medicines, long-term use of corticosteroids)
This list does not include every possible risk factor for osteoporosis.
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Preventing osteoporosis
Preventing osteoporosis
Strategies to prevent osteoporosis can be most effective before symptoms start. Calcium, vitamin D and weight-bearing exercise are important for bone health.
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Calcium
Calcium
Why we need calcium for bone health Calcium is essential for your body to function properly. It is also used to build your bones and keep them strong and healthy. Most of the calcium you eat is stored in your bones and teeth. Each day you use calcium for essential functions and lose some through your skin, nails, hair, sweat, urine and faeces. When you don’t get enough calcium in your diet, your body removes calcium from your bones and teeth. How much calcium is enough? On average, each person needs 1000 mg calcium each day. Teenagers, women over 50 and men over 70 need 1300 mg per day. Foods that are rich in calcium include milk, yoghurt, cheese, tinned salmon, tofu.
A list of the amounts of calcium in foods is available from Osteoporosis Australia. Calcium supplements are available for people who cannot get enough calcium from foods.
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Vitamin D
Vitamin D
Why we need vitamin D for bone health Vitamin D is essential for a healthy body, including healthy bones. Vitamin D helps your body to absorb the calcium from your food. The main way your body gets vitamin D is from sunlight. Your skin makes vitamin D naturally after exposure to the UVB rays in sunlight. There are also small amounts of vitamin D in some foods (e.g. salmon, tuna, mackerel). Vitamin D supplements are available for people who cannot get enough vitamin D. How much sunshine is enough? The amount of sunshine you need to make enough vitamin D depends on where you live and your skin type. For example:
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In summer, 5 minutes of exposure to sunlight in mid-morning or mid-afternoon may be enough for people with moderately fair skin.
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In winter, up to 30 minutes of exposure to sunlight at midday may be enough for people with moderately fair skin.
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People with dark skin need more exposure than people with fair skin.
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Longer exposure times are needed in winter than in summer, and in southern regions of Australia than northern regions.
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Too much exposure to sunlight increases your risk of skin cancer.
Estimated sun exposure times are available from Osteoporosis Australia
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Weight-bearing exercise
Weight-bearing exercise
Why we need exercise for bone health Exercise is vital to build and maintain healthy bones. Weight-bearing exercises increase bone density. Weight-bearing exercise means exercise done standing upright, which puts the full weight of your body onto your bones (e.g. walking, skipping, dancing, tennis, weight training) Non weight-bearing exercises (e.g. cycling, swimming) do not increase bone density. Physical activities that do not increase bone density can still help prevent falls and fractures by building up muscle strength and by improving or maintaining coordination and balance. How much exercise is enough? 30 minutes of weight-bearing exercise, 3–5 times per week.
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Bone density tests
Bone density tests
A bone density scan is the standard test for measuring bone density and diagnosing osteoporosis. Heel ultrasound is another method of bone density testing. It is sometimes used as a screening test to identify people who may be at risk of osteoporosis. Screening tests alone cannot diagnose osteoporosis accurately and they should not be used to check how your osteoporosis medicine is working. If you have previously had a different test for osteoporosis, the results cannot be compared.
The results of bone density tests are usually given as two scores:
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The T-score compares your bone density with the average for young adults.
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The Z-score compares your bone density with the average for people of your sex and age group.
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- Additional Resources