Osteoporosis can be treache-rous; many affected people do not notice the reduction in their bone density, and it is often the case that doctors only detect it after the patient falls and fractures a bone.

Porous bones break easily and heal badly, so what would have been a harmless bump for a young person may leave an older person permanently in a rest home.

Osteoporosis is, according to the World Health Organization (WHO), one of the world’s 10 most common diseases, and it is not curable.

“As we age, the osteoporosis risk rises,” explains Dr Andreas Kurth, an orthopaedics surgeon.

Muscles and bones in the human body generally start to deteriorate after we turn 40.

A bone density test in the lumbar vertebrae and the hips is used to detect early signs that the patient may face a particularly high risk of suffering osteoporosis.

“Density is tested with a special X-ray procedure,” says Sonja Endres, of the Self-Help Association for Osteoporosis Patients.

Bone density is calculated from the amount of radiation that makes it through the bones. The result is later combined with risk factors like age and gender, to give you a score.

Once bone density has decreas- ed, the best the patient can hope for is halting the process.

That is why it is important to strengthen one’s bones as soon as possible, for example with exercise.

“That includes, in everyday life, carrying your own shopping or taking the stairs instead of the lift,” Dr Kurth says.

Endres also recommends regular strength training, since strong muscles also strengthen the bones they are connected to.

Beyond exercise, certain nutrients also have an effect on bone density, particularly calcium and vitamin D.

Calcium can be found in milk and milk products like cheese and yoghurt, as well as in vegetables, pulses, nuts and seeds.

Adults need 1,000 milligrams of calcium per day, and they can reach that amount with a slice of cheese, a portion of kale and a glass of milk, for example.

“Vitamin D stimulates the absorption of calcium from the gastrointestinal tract, as well as the bone hardening process,” says Antje Gahl, of the German Nutrition Society.

Vitamin D can also help increase muscle strength and reduce imba- lances. However, it is only found naturally in very few foodstuffs, including fatty fish like salmon and herring.

Most of the body’s vitamin D is built up through the effects of sunlight on the skin.

If you want to increase your intake, you should get out into the sun, ideally for 25 minutes a day between spring and autumn.

If that does not work, there are certain situations where vitamin D supplements may be recommended.

With age, the skin tends to accumulate less vitamin D.

People who are 60 or older should consult their doctor to see whether vitamin D pills would be appropriate for them. Experts recommend a daily dose of 800-1,000 international units. – dpa