The Auckland calcium study: 5-year post-trial follow-up
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Five years after completion of a randomised placebo-controlled trial of calcium supplements, there was no effect of calcium on total fracture incidence, a significant reduction in vertebral and forearm fractures and, in a subset, no effect on bone density. There was no increased risk of cardiovascular events after discontinuation of calcium.
The Auckland calcium study was a 5-year randomised controlled trial of 1 g/day calcium citrate in 1,471 postmenopausal women. Calcium did not reduce total, vertebral or forearm fracture incidence, increased hip fracture incidence and had beneficial effects on bone mineral density (BMD). A secondary analysis raised concerns about the cardiovascular safety of calcium. The purpose of this study was to determine whether the effects of calcium on fracture incidence, BMD and cardiovascular endpoints persisted after supplement discontinuation.
Approximately 5-years post-trial, we collected information on the 1,408 participants alive at trial completion from the national databases of hospital admissions and deaths. We contacted 1,174 women by phone, and from these we obtained information on medical events and post-trial calcium use. We undertook BMD measurements at 10 years in a selected subset of 194 women who took study medication for 5 years in the original trial, and did not take bone-active medications post-trial.
Over the 10-year period, there was no effect on total fracture (HR 0.90, 95 % CI 0.75–1.07) or hip fracture incidence (1.40, 0.89–2.21), but significant reductions in forearm (0.62, 0.43–0.89) and vertebral fractures (0.52, 0.32–0.85) in those assigned to calcium. There were no between-group differences in BMD at 10 years at any site. The adverse cardiovascular outcomes observed in the 5-year trial did not persist post-trial.
Calcium supplementation for 5 years had no effect on total fracture incidence at 10 years. The positive benefits on BMD and the adverse cardiovascular effects did not persist once supplements were stopped.
KeywordsBone densitometry Calcium supplements Fracture Myocardial infarction Stroke
Conflicts of interest
This study was funded by the Health Research Council of New Zealand, Greenlane Research Education Fund of New Zealand, Francis and Phyllis Thornell Shore Memorial Scholarship and the Estate of Grace EM Kay Orakau Heart Research Scholarship Trust of New Zealand.
- 8.Grant AM, Avenell A, Campbell MK, McDonald AM, MacLennan GS, McPherson GC, Anderson FH, Cooper C, Francis RM, Donaldson C, Gillespie WJ, Robinson CM, Torgerson DJ, Wallace WA (2005) 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 trial. Lancet 365:1621–1628PubMedCrossRefGoogle Scholar
- 10.Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, Burckhardt P, Li R, Spiegelman D, Specker B, Orav JE, Wong JB, Staehelin HB, O'Reilly E, Kiel DP, Willett WC (2007) Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomised controlled trials. Am J Clin Nutr 86:1780–1790PubMedGoogle Scholar
- 11.Avenell A, Gillespie WJ, Gillespie LD, O'Connell D 2009 Vitamin D and vitamin D analogues for preventing fractures associated with involutional and post-menopausal osteoporosis. Cochrane Database Syst Rev CD000227Google Scholar
- 16.Avenell A, MacLennan GS, Jenkinson DJ, McPherson GC, McDonald AM, Pant PR, Grant AM, Campbell MK, Anderson FH, Cooper C, Francis RM, Gillespie WJ, Robinson CM, Torgerson DJ, Wallace WA (2012) Long-term follow-up for mortality and cancer in a randomised placebo-controlled trial of vitamin D3 and/or calcium (RECORD trial). J Clin Endocrinol Metab 97:614–622PubMedCrossRefGoogle Scholar