There is no single cause of osteoporosis but there are many risk factors. These include:
- Older age (>50 years)
- Female gender
- Thin build
- Physical inactivity
- Family history of osteoporosis
- Excessive alcohol or caffeine consumption
- Low dietary calcium intake
- Low levels of vitamin D
- Long-term use of some medications eg: corticosteroids, thyroid medications, epilepsy medications
- Deficiency of oestrogen in women eg: post-menopausal, irregular periods, surgical removal of the ovaries, early menopause (before the age of 40 years)
- Some medical conditions eg: endocrine diseases such as Cushing's syndrome and thyrotoxicosis; rheumatoid diseases such as rheumatoid arthritis; blood disorders such as multiple myeloma.
Signs and symptoms
There are usually no symptoms of osteoporosis until a bone breaks. For this reason it is often referred to as a "silent disease". Fractures of the wrist, hip, spine, pelvis and upper arm are most common in osteoporosis. The fractures can be very painful and can lead to disability and loss of independence.
Over time there may be a gradual loss in height due to weakened and compressed vertebrae in the spine. Spinal fractures or crumbling of affected vertebral bones can lead to a Dowager’s Hump or Widow’s Hump. This results in an increasingly bent-over posture and may cause back pain.
Treatment for osteoporosis will depend upon the results of bone density scans, age, gender, medical history and the severity of the condition. Treatment most commonly involves lifestyle changes and medications and aims to maximise bone density and reduce the risk of bone fracture.
If possible, regular weight bearing exercise (eg: walking, tennis, golf) should be maintained as it can help to reduce bone loss and stimulate new bone formation. To be of benefit, doctors recommend at least 30 minutes of exercise at least three times a week. Prior to beginning any new exercise it is important to consult a doctor to ensure that the proposed exercise is safe to undertake.
As the body cannot make its own calcium, a diet high in calcium is necessary and helps to slow the rate of bone loss. Vitamin D is also essential as it enables calcium to be effectively absorbed by the body. Eating a balanced diet that includes calcium and vitamin D-rich foods is important in supplying the bones with the calcium required. Foods high in calcium include dairy products, dark green vegetables, beans, legumes, fish (especially sardines or salmon which are eaten with the bones), soybean products, cereals and nuts. It is recommended that at least 1000mg of calcium is taken in each day. Foods high in vitamin D include sardines, tuna, eggs and liver.
Smokers will be advised to stop smoking. Minimizing alcohol and caffeine intake (eg: tea, coffee, cola drinks) may also be recommended.
Regular but moderate exposure to sunlight helps to produce vitamin D in the body. Note, excess sun exposure poses other health risks.
It is important to take extra care with movement and daily activities in order to minimise the risk of fractures. This can include using mobility aids if unsteady on the feet, removing objects or hazards that can lead to falls (eg: loose floor rugs), installing hand rails in areas such as entranceways and bathrooms, and using non-slip mats in the bath or shower. Padding to protect vulnerable parts of the body eg: the hips, can also help in the prevention of fractures. Special "hip protectors" have been developed for this purpose. These can be enquired about at GP clinics and pharmacies.
If dietary intake of calcium is insufficient, calcium supplements may be prescribed in order to increase the amount of calcium available in the body. A dosage of 1000mg per day in usually recommended.
As vitamin D is important for the effective absorption of calcium into the bones, vitamin D supplements such as calciferol are usually given in conjunction with calcium supplements. An activated form of vitamin D called calcitriol (Rocaltrol) has also been shown to be beneficial.
These non-hormonal medications can increase bone density by reducing the rate of bone loss. They have been shown to reduce the fracture rate in people with osteoporosis. These medications are usually given in an alternating cycle with calcium supplements. Common bisphosphonate medications used in the treatment of osteoporosis include alendronate (Fosamax) and zoledronic acid (Aclasta). A common side effect of these medications is nausea and indigestion. This can limit their use in some people.
Hormone replacement therapy (HRT) medications that include oestrogen are sometimes recommended for women with osteoporosis. HRT has been shown to reduce bone loss and may increase bone density. While HRT has obvious benefits in the treatment and prevention of osteoporosis, recent research has indicated that there are risks with long term HRT use. It is therefore important that the patient and their practitioner discuss the benefits and risks of taking the medication.
Prevention is better than treatment and evidence suggests that maximising bone density in early and middle life helps to reduce the risk of osteoporosis in later life. Steps that can be taken to help prevent osteoporosis include:
- Not smoking
- Limiting alcohol intake
- Undertaking regular weight bearing exercise
- Maintaining a healthy body weight
- Considering HRT for women during menopause
|Children||9-13 years||1,000-1,300 mg|
|Children||14-18 years||1,300 mg|
|Men||19-70 years||1,000 mg|
|Men||70+ years||1,300 mg|
|Women||19-50 years||1,000 mg|
|Women||50-70+ years||1,300 mg|
Further information and support
PO Box 688, Wellington, 6140
Ph: (04) 499 4862