Your body also needs calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in the body.
Your body cannot make calcium. The body only gets the calcium it needs through the food you eat, or from supplements. If you do not get enough calcium in your diet, or if your body does not absorb enough calcium, your bones can get weak or will not grow properly.
Your skeleton (bones) are a living organ. Bones are constantly being remodeled with old bone being resorbed and new bone being formed. It takes about 10 years for all the bone in your body to be renewed. That is why paying attention to bone health is important in adults and not just in growing children.
Bone density refers to how much calcium and other minerals are present in a section of your bone. Bone density is highest between ages 25 and 35. It goes down as you get older. This can result in brittle, fragile bones that can break easily, even without a fall or other injury.
The digestive system is normally very bad at absorbing calcium. Most people absorb only 15% to 20% of the calcium they eat in their diet. Vitamin D is the hormone that helps the gut absorb more calcium.
Many older adults have common risks that make bone health worse. Calcium intake in the diet (milk, cheese, yogurt) is low. Vitamin D levels are low and gut calcium absorption is low. In many adults, hormonal signals have to take some calcium out of the bones every day to keep blood calcium levels normal. This contributes to bone loss.
Because of this, as you age, your body still needs calcium to keep your bones dense and strong. Most experts recommend at least 1,200 milligrams of calcium and 800 to 1,000 international units of vitamin D a day. Your health care provider may recommend a supplement to give you the calcium and vitamin D you need.
Some recommendations call for much higher doses of vitamin D, but many experts feel that high doses of vitamin D are not safe for everyone. In addition, very high amounts calcium in your diet can lead to health problems such as constipation, kidney stones, and kidney damage. If you are concerned about bone health, be sure to discuss with your provider whether supplements of calcium and Vitamin D are a good choice for you.
People who have gut-related diseases (inflammatory bowel disease, gastric bypass surgery), parathyroid gland disease, or are taking certain medications may need different recommendations for calcium and vitamin D supplementation. Talk to your provider if you are unsure about how much calcium and vitamin D to take.
Follow a diet that provides the proper amount of calcium, vitamin D, and protein. These nutrients will not completely stop bone loss, but they will help ensure that your body has the materials it needs to build bones. Remaining fit and active can also protect bones and keep them stronger. Avoiding smoking also protects bones and keeps them stronger.
High-calcium foods include:
- Ice cream
- Leafy green vegetables, such as spinach and collard greens
- Sardines (with the bones)
Osteoporosis literally means ‘bones with holes’. It occurs when bones lose minerals such as calcium more quickly than the body can replace them. They become less dense, lose strength and break more easily.
Most people don’t realise they have osteoporosis until a fracture happens, as there are usually no signs or symptoms. This is why osteoporosis is often called the ‘silent disease’. Osteoporosis particularly affects women in their middle and later years, although some men are also affected.
If you have osteoporosis, lifestyle changes and medical treatment can prevent further bone loss and reduce your risk of bone fractures.
Osteoporosis and bone growth
Bone is formed by specialised cells. Like the rest of the body, bone is constantly being broken down and renewed. It is living tissue that needs exercise to gain strength, just like muscle.
In the early years of life, more bone is made than is broken down, resulting in bone growth. By the end of your teens, bone growth has been completed and by about 25 to 30 years of age, peak bone mass is achieved.
Sex hormones, such as oestrogen and testosterone, have a fundamental role in maintaining bone strength in men and women. The fall in oestrogen that occurs during menopause results in accelerated bone loss. During the first five years after menopause, the average woman loses up to 10 per cent of her total body bone mass.
Fractures of the spine caused by osteoporosis can lead to pain, loss of height and changes in posture, such as the ‘dowager’s hump’. This hump is caused when spinal fractures are compressed due to the force of gravity, resulting in an abnormal bending forward of the spine called kyphosis.
Symptoms of osteoporosis
Osteoporosis causes no specific pain or symptoms. However, it does increase the risk of serious or debilitating fractures. If you think you may be at risk of developing osteoporosis, see your doctor.
Diagnosis of osteoporosis
Currently, the most reliable way to diagnose osteoporosis is to measure bone density with a dual-energy absorptiometry scan or DXA. A DXA scan is a short, painless scan that measures the density of your bones, usually at the hip and spine and, in some cases, the forearm.
You can qualify for a Medicare rebate for a DXA scan if you:
- have previously been diagnosed with osteoporosis
- have had one or more fractures due to osteoporosis
- are aged 70 years or over
- have a chronic condition, including rheumatoid arthritis, coeliac disease or liver disease
- have used corticosteroids for a long time.
Your doctor will be able to tell you whether you fit the criteria to receive a Medicare rebate. It is possible to have a DXA scan performed if you do not fit the criteria for the Medicare rebate, however, there will usually be an out-of-pocket cost associated with the scan.
Risk factors for osteoporosis
There are many risk factors for osteoporosis, some of which you cannot change, such as being female, and having a direct relative who has had an osteoporotic fracture.
Other risk factors include:
- inadequate amounts of dietary calcium
- low vitamin D levels
- cigarette smoking
- alcohol intake of more than two standard drinks per day
- caffeine intake of more than three cups of coffee or equivalent per day
- lack of
- (before the age of 45)
- loss of menstrual period if it is associated with reduced production of oestrogen, which is vital for healthy bones (the menstrual cycle can cease following excessive dieting and exercise)
- long-term use of medication such as corticosteroids for rheumatoid arthritis, asthma and other conditions.
Some conditions place people at a higher risk of osteoporosis. These conditions include:
- thyroid disease or an overactive thyroid gland
- rheumatoid arthritis
- chronic liver and kidney disease
- conditions that affect the body’s ability to absorb nutrients, such as Crohn’s disease, coeliac disease and other inflammatory bowel conditions.
Prevention of osteoporosis
From a young age, both men and women can take steps to prevent osteoporosis by making sure that they:
- have a healthy and varied diet with plenty of fresh fruit, vegetables and whole grains
- eat calcium-rich foods
- absorb enough
- limit consumption
- do regular weight-bearing and strength-training activities.
Calcium-rich diet and osteoporosis
Enjoying a healthy, balanced diet with a variety of foods and an adequate intake of calcium is a vital step to building and maintaining strong, healthy bones. If there is not enough calcium in the blood, your body will take calcium from your bones. Making sure you have enough calcium in your diet is an important way to preserve your bone density.
It is recommended that the average Australian adult consumes 1,000 mg of calcium per day. Postmenopausal women and men aged over 70 years are recommended to have 1,300 mg of calcium per day. Children, depending on their age, will need up to 1,300 mg of calcium per day.
Dairy foods have the highest levels of calcium, but there are many other sources of calcium, including sardines, spinach and almonds. If you are unable to get enough calcium from your diet alone, you may need to talk to a health professional about calcium supplements.
Vitamin D and osteoporosis
Vitamin D and calcium promote bone density. Vitamin D is important because it helps your body absorb the calcium in your diet. We obtain most of our vitamin D from the sun, and there are
Vitamin D can also be found in small quantities in foods such as:
- fatty fish (salmon, herring, mackerel)
- fortified foods such as low-fat milks and margarine.
For most people, it is unlikely that adequate quantities of vitamin D will be obtained through diet alone. Talk with your health professional about vitamin D supplements if you are concerned that you are not getting enough vitamin D.
Exercise to prevent osteoporosis
Weight-bearing exercise encourages bone density and improves balance so falls are reduced. It does not treat established osteoporosis. Consult your doctor, especially if you have been sedentary, are over 75 years of age or have a medical condition.
General recommendations include:
- Choose weight-bearing activities such as brisk walking, jogging, tennis, netball or dance. While non-weight-bearing exercises, such as swimming and cycling, are excellent for other health benefits, they do not promote bone growth.
- Include some high-impact exercise into your routine, such as jumping and rope skipping. Consult your health professional – high-impact exercise may not be suitable if you have joint problems, another medical condition or are unfit.
- Strength training (or ) is also an important exercise for bone health. It involves resistance being applied to a muscle to develop and maintain muscular strength, muscular endurance and muscle mass. Importantly for osteoporosis prevention and management, strength training can maintain, or even improve, bone mineral density. Be guided by a health or fitness professional (such as an ) who can recommend specific exercises and techniques.
- Activities that promote muscle strength, balance and coordination – such as , – are also important, as they can help to prevent falls by improving your balance, muscle strength and posture.
- A mixture of weight-bearing and strength-training sessions throughout the week is ideal. Aim for 30 to 40 minutes, four to six times a week. Exercise for bone growth needs to be regular and have variety.
Lifestyle changes to protect against osteoporosis
Be guided by your doctor, but general recommendations for lifestyle changes may include:
- – smokers have lower bone density than non-smokers
- get some sun – exposure of some skin to the sun needs to occur on most days of the week to allow enough vitamin D production (but keep in mind the recommendations for sun exposure and skin cancer prevention)
- drink alcohol in moderation, if at all – excessive alcohol consumption increases the risk of osteoporosis. Drink no more than two standard drinks per day and have at least two alcohol-free days per week
- limit caffeinated drinks – excessive caffeine can affect the amount of calcium that our body absorbs. Drink no more than two to three cups per day of cola, tea or coffee.