Calcium and vitamin D fight fractures

13th January 2010 — Studies involving 68,517 elderly fracture patients in Europe and the US suggest taking supplements of calcium and vitamin D every day reduces the risk of broken bones, irrespective of age, sex or previous fractures.

The supplements need to be taken together to work effectively.

Fractures are a major cause of illness in older people, with around 230,000 broken bones a year in the UK as a result of osteoporosis.

The case for supplements

Previous studies have produced conflicting findings about the protective effects of calcium and vitamin D – alone and together.

A team of researchers based at Gentofte Hospital in Copenhagen and the University of Southern Denmark analysed data from seven large trials. The average age of the patients was 70.

The findings are published today in the BMJ.

How much to take?

The study found that vitamin D given alone in doses of 10-20 μg/day is not effective in preventing fractures.

Calcium and vitamin D – given together – reduce hip fractures and total fractures and probably vertebral fractures, irrespective of patients’ age, sex or whether they’ve broken bones before.

However, this report does not clear up the problem of the best dose to use, which patients benefit most and which fractures are helped by these supplements.

More research needed

The authors emphasise that their study does not allow for a direct comparison of vitamin D against vitamin D taken with calcium, but only comparisons between each supplement and no treatment.

They say additional studies of vitamin D are also needed, especially trials of it given daily in higher doses without calcium.

The Danish researchers were assisted by colleagues in several countries, including experts from the Department of Health Care of Older People at Queen’s Medical Centre in Nottingham.

In an editorial to accompany the study, Professor Opinder Sahota from Nottingham says that, although the evidence is still confusing, there is growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing non-vertebral fractures.

National Osteoporosis Society responds

Rob Dawson, senior communications officer for the National Osteoporosis Society, told us by email: “The research highlights the important role that vitamin D and calcium play in bone strength.

“Calcium plays an important structural role in the development and maintenance of bone tissue. Vitamin D controls the absorption of calcium from the intestine. Of course, many people will not need a calcium and vitamin D supplement. If you already get all the calcium that you need from your diet, and vitamin D from exposure to sunshine, then a supplement will not be necessary. There is no evidence to suggest that taking more than the required level will provide any extra benefit for your bones.

“Calcium and vitamin D supplements can be used together to help prevent fractures in frail older people. However, if you have already suffered a fracture it is likely that your doctor will want to consider a stronger treatment than just calcium and vitamin D.

“For people under 75, calcium and vitamin D is not generally considered as a treatment option but can be used as part of a lifestyle approach to maintaining bone health.”

Mr Dawson says people shouldn’t just focus on supplements to protect their bones.

“A combination of weight-bearing exercise, a well-balanced diet (including foods from a mixture of nutrients including protein and carbohydrates, fruit, vegetables and dairy products), not smoking, moderate alcohol intake and the use of a calcium supplement can all enhance the effectiveness of your osteoporosis medication.”

You can read more about osteoporosis and protecting your bones here.