Primary care Randomised controlled trial of supplementation with calcium and cholecalciferol (vitamin D3) for prevention of fractures in primary care

Objective To assess whether supplementation with calcium and cholecaliferol (vitamin D3) reduces the risk of fracture in women with one or more risk factors for fracture of the hip. Design Pragmatic open randomised controlled trial. Setting Practice nurse led clinics in primary care. Participants 3314 women aged 70 and over with one or more risk factors for hip fracture: any previous fracture, low body weight ( < 58 kg), smoker, family history of hip fracture, or fair or poor self reported health. Intervention Daily oral supplementation using 1000 mg calcium with 800 IU cholecaliferol and information leaflet on dietary calcium intake and prevention of falls, or leaflet only (control group). Main outcome measures Primary outcome measure was all clinical fractures and secondary outcome measures were adherence to treatment, falls, and quality of life (measured with the SF-12). Results 69% of the women who completed the follow-up questionnaire at 24 months were still taking supplements (55% with inclusion of randomised participants known to be alive). After a median follow-up of 25 months (range 18 to 42 months), clinical fracture rates were lower than expected in both groups but did not significantly differ for all clinical fractures (odds ratio for fracture in supplemented group 1.01, 95% confidence interval 0.71 to 1.43). The odds ratio for hip fracture was 0.75 (0.31 to 1.78). The odds of a woman having a fall at six and 12 months was 0.99 and 0.98, respectively. Quality of life did not significantly differ between the groups. Conclusion We found no evidence that calcium and vitamin D supplementation reduces the risk of clinical fractures in women with one or more risk factors for hip fracture. Registration ISRCTN26118436, controlled trials registry. Introduction Supplementation with calcium and vitamin Dmight be expected to prevent fractures in older people not only through reductions in bone loss but by reducing falls. We assessed whether giving calcium and vitamin D supplements to community dwelling older women at increased risk of hip fracture would reduce their risk of any fracture. Participants and methods We identified women aged 70 and over who had at least one self reported risk factor for hip fracture: low bodyweight ( < 58 kg), any previous fracture, maternal history of hip fracture, smoker, and poor or fair health. We assessed self reported calcium consumption through a brief 10 item questionnaire and risk factors for fracture. Women were excluded if they were receiving any calcium supplementation of more than 500 mg a day or had a history of kidney or bladder stones, renal failure, or hypercalcaemia. Recruitment and randomisation We asked general practices across England to post information about the study, a consent form, and a questionnaire on risk factors for fracture to all women aged 70 and over. The women were asked to return completed questionnaires to the relevant trial coordinating centres. Eligible women were randomised (stratified by practice) by computer at the York Trials Unit by an independent person with no knowledge of the participants’ characteristics. We initially randomised in favour of the control group in a 2:1 ratio as this was hypothesised to be the most efficient allocation ratio given the study resources. We included research related costs, not the costs of the supplements, in the Details of previous trials are on bmj.com This is the abridged version; the full version is on bmj.com York Trials Unit, Department of Health Sciences, University of York, York YO10 5DD Yvonne Birks research fellow Sarah Cockayne research fellow Jo Dumville research fellow Cynthia Iglesias research fellow Jill Porthouse research fellow Suezann Puffer research assistant David J Torgerson director Ian Watt professor of primary care Bone Clinic, Freeman Hospital, Newcastle upon Tyne Terry Aspray consultant geriatrician Roger Francis consultant physician Christine King personal assistant Elizabeth Steele registered general nurse Anne Sutcliffe osteoporosis specialist nurse Hertfordshire Primary Care Network, Ware, Herts Mike Baverstock general practitioner Lucy Saxon research coordinator Correspondence to: D J Torgerson [email protected]