U.K. Trials Question Supplements' Efficacy on Fracture in Elderly

ABERDEEN, Scotland & YORK, England--Two studies out of the United Kingdom question the ability of calcium and vitamin D supplements to prevent fractures in high-risk populations, including elderly women and those with previous osteoporotic fractures. The studies, released in early online version of The Lancet and British Medical Journal, sought to examine whether supplementation could prevent primary or secondary fractures.

The first study, coordinated by the RECORD Trial Group at the University of Aberdeen, included more than 5,000 Scots over the age of 70, 85 percent of whom were women, who had suffered a low-trauma osteoporotic fracture in the previous 10 years. Participants were randomized to receive 800 IU/d of vitamin D3, 1,000 mg/d of calcium, the two supplements combined or a placebo. Follow-up assessments were conducted at 24 and 62 months for the primary outcome of new fractures. The researchers found no difference in fracture incidence between the placebo and supplement groups for calcium, vitamin D or the combination; they concluded oral supplementation with calcium and vitamin D3 does not prevent further fractures in previously mobile elderly people.

In the second study, researchers from the University of York enrolled 3,314 free-living women over the age of 70 with one or more risk factors for hip fracture, including previous fractures, low body weight, smoking or poor health. The women were randomized to receive 1,000 mg/d of calcium plus 800 IU/d vitamin D3 or a placebo; all women received information on general prevention of falls. Clinical fracture rates were lower than expected in both groups, but did not differ between the groups. The researchers concluded there was no benefit from supplementation to reduce the risk of hip fracture in women with one or more risk factors.

The studies' findings were surprising, given previous studies that have shown substantive benefits to calcium and vitamin D supplementation on bone mineral density (BMD). Both new studies referenced past studies in the United States and France that did show the nutrients' ability to reduce fracture incidence and increase BMD.

In addition, both new studies had significant compliance concerns, with only 60 percent of respondents taking their supplements more than 80 percent of the time by the two-year mark. The compliance issue was specifically pointed out in an accompanying Lancet commentary by Philip Sambrook from the Royal North Shore Hospital in Sydney, Australia. "Compliance with medication was only moderate," he wrote. "It declined to 63 percent after two years and might have been as low as 45 percent when non-responders to the questionnaire about compliance were included."

Andrew Shao, Ph.D., vice president of scientific and regulatory affairs for the Council for Responsible Nutrition (CRN), agreed that the compliance issue could have seriously compromised the study results. He added it is important to consider the studies in context. "Realistically, FDA [the Food and Drug Administration] approved a health claim linking calcium intake with a reduced risk of osteoporosis, which covered reams of research," he said. "And there are many studies linking bone density and vitamin D. So it is important to consider all of the science. There is no reason for the majority of the aging population to stop taking their calcium and vitamin D supplements; it would be a mistake."