Calcium supplementation

Increasing daily calcium will not reduce the risk of fractures in later life, study suggests

While moderate amounts of calcium (around 700mg a day) are vital for maintaining healthy bones, there is no need to start increasing calcium intake in order to reduce the risk of fractures or osteoporosis in later life, finds a paper published on the British Medical Journal website this week.

As people age, their bones lose calcium and they are more at risk of fractures and osteoporosis – this is especially the case for women. As well as causing individual suffering, fractures are a huge drain on health services.

With aging populations, this burden will increase in the coming years and therefore preventing them is a major public health issue, say the authors, led by Dr Eva Warensjö from Uppsala University in Sweden.

The importance of increasing calcium intake to compensate for the loss of calcium has been debated for a long time and there is still no clear advice. This is reflected by the wide range of daily calcium recommendations for the over fifties – in the UK it is currently 700mg; it is 800mg in Scandinavia and 1 200mg in the US.

In order to investigate the links between long-term dietary calcium intake and the risk of fractures, the authors reviewed data from a large population study of Swedish women carried out in 1987.

Over 61 433 women (born between 1914 and 1948) took part in the Swedish Mammography Study and of these 5 022 participated in a smaller sub-research group. All participants were followed up for 19 years.

During the follow-up, 14 738 (24%) women had a first fracture and, of these, 3 871 (6%) had a first hip fracture. Twenty percent of the sub-group had osteoporosis.

The researchers used a series of questionnaires to gain in-depth knowledge of the participants’ changing diet and in particular their calcium intake and use of supplements and multivitamins.

The women also provided information about their menopausal status, whether or not they used post-menopausal oestrogen therapy, their weight, height, smoking habits, how much physical activity they did and their educational attainment.

The results show that women had the lowest risk of having a fracture when they consumed around 750mg a day of calcium. However, the fracture risk in women who started to increase their calcium intake over time did not decrease.

There is some evidence that high intake of calcium may actually increase the rate of hip fractures, though the authors stress that this result needs to be interpreted with caution.

The authors conclude that while low levels of calcium intake (less than 700mg per day) increase the risk of fractures and osteoporosis, there is no need to start increasing calcium intake above the amount. Increases did not further reduce the fracture and osteoporosis risk.

Journal Reference:

  1. E. Warensjo, L. Byberg, H. Melhus, R. Gedeborg, H. Mallmin, A. Wolk, K. Michaelsson. Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study. BMJ, 2011; 342 (may24 1): d1473 DOI: 10.1136/bmj.d1473

Further reading:

Osteoporosis: Calcium And Exercise To Strengthen The Bones — Do You Get Enough? (Sep 14, 2008) — A stumble, a fall — a broken bone: many older people are afraid of this happening. The German Institute for Quality and Efficiency in Health Care has published information about how you can protect …  > read more

Case For Daily Calcium Pill Strengthened (Aug 28, 2007) — A new study has found people over 50 who take calcium supplements suffer fewer fractures and enjoy a better quality of life. The study involved a meta-analysis of over 63,000 people taking calcium or …  > read more

Calcium Alone Does Not Reduce Hip Fracture Risk (June 30, 2008) — People, especially the elderly, may reach for calcium supplements in hopes of protecting themselves against bone fractures in case of a fall. But a recent analysis of several studies found no …  > read more

Calcium Supplements Fail To Prevent Bone Fractures In Children (Oct 1, 2006) — Calcium supplements have very little benefit for preventing fractures in childhood and later adulthood, concludes a study in the British Medical …  > read more

Calcium Supplements Linked to Increased Risk of Heart Attack, Study Finds (July 30, 2010) — Calcium supplements, commonly taken by older people for osteoporosis, are associated with an increased risk of a heart attack, a new study …  > read more