In contrast to two recently published studies indicating that regular supplements of calcium and vitamin D may not effectively prevent fractures, a newly published meta-analysis in the May 11 issue of the Journal of the American Medical Association shows that 700 to 800 IU of vitamin D reduce risk nonvertebral fractures in the elderly.1

The new meta-analysis combines the results of five randomized controlled trials (RCTs) that measured hip fracture rates and seven that assessed rates of all nonvertebral fractures. The pooled data indicate that a vitamin D dose of 700 to 800 IU/day, with or without calcium, reduced the relative risk of hip fracture by 26% and any nonvertebral fracture by 23% versus calcium or placebo. No significant benefit was observed among RCTs that studied doses of 400 IU/day.

"The role of calcium supplementation together with 700 to 800 IU/day of vitamin D could not be clearly defined, but dietary intakes of more than 700 mg/day may be necessary for nonvertebral fracture prevention," conclude researchers led by Heike A. Bischoff-Ferrari, MD, MPH, of the nutrition department at the Harvard School of Public Health in Boston, Massachusetts. "Our results are compelling for general vitamin D supplementation...in elderly persons."

Felicia Cosman, MD, an osteoporosis specialist at Helen Hayes Hospital in West Haverstraw, New York, and professor of clinical medicine at Columbia University in New York City agrees with the findings.

"Most of us believe the conclusion of this meta-analysis that vitamin D at 700 to 800 IU/day is effective at reducing risk of fractures, but by no means is that [risk reduction] enough in high-risk individuals," she tells CIAOMed. "There is no question at all that anybody who has osteoporosis by bone mineral density (BMD) or fracture should be offered medication along with calcium and vitamin D."

 

Recent studies show no risk reduction

The Randomised Evaluation of Calcium or vitamin D (RECORD) trial in 5292 patients, recently published in The Lancet,2 found that fracture risk in participants receiving either 1 g/day of calcium, 800 IU/day of vitamin D3, both, or placebo was similar among all groups. A second study in the British Medical Journal also found no evidence that calcium and vitamin D supplements reduce the risk of fractures in women aged 70 and over with one or more risk factors for hip fracture.3

Calling these negative results "a surprise," Dr. Cosman says, "We really want to believe the preponderance of literature, which suggests calcium and vitamin D are effective at reducing-although by no means eliminating-osteoporosis fractures."

She adds that "all the biology is there," noting that vitamin D and calcium "affect surrogate markers of bone mass and turnover, and most studies suggest they reduce risk of fractures as well."

 

Alendronate not cost-effective in osteopenic population

While patients with osteoporosis and/or previous fractures can benefit from phramacologic therapy, the use of alendronate may not be cost-effective in the osteopenic population (femoral neck T-scores of >-2.5), according to a recently published study in the May 3rd issue of Annals of Internal Medicine.4 In this study, researchers used computer simulations to analyze published studies and to estimate the cost and outcomes of 5 years of treatment versus no drug therapy. They found alendronate therapy for a postmenopausal woman with osteopenia costs between $70,000 and $332,000 per year.

"Patients in the osteopenia range of BMD who have not had fractures and are not yet osteoporotic may be better served by treatment with calcium and vitamin D supplementation and exercise as preventive measures," Dr. Cosman says.

References:

  1. Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA. 2005;293:2257-2264.
  2. Grant AM, Avenell A, Campbell MK, et al. Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled study. Lancet. 2005;365:1621-1628.
  3. Porthouse J, Cockayne S, King C, et al. Randomized controlled trial of supplementation with calcium and cholecalciferol (vitamin D3) for prevention of fractures in primary care. BMJ. 2005;330:1003-1006.
  4. Schousboe JT, Nyman JA, Kane RL, Ensrud KE. Cost-effectiveness of alendronate therapy for osteopenic postmenopausal women. Ann Int Med. 2005;142:734-741.