Giving elderly people regular supplements of vitamin D and calcium to prevent secondary bone fractures is ineffective, concludes a randomised trial published online today by The Lancet.
Elderly people who have osteoporosis have a high risk of bone fractures and those who previously had a fracture are at an increased risk of having another. Vitamin D and calcium, alone or in combination, are often recommended for the prevention of osteoporotic fractures.
In the study Adrian Grant (University of Aberdeen, UK) and colleagues recruited around 5 300 people aged 70 years or older who had suffered a fracture in the last 10 years from 21 hospitals across the UK. Participants were randomly assigned to take a daily supplement of vitamin D3, calcium, both, or a placebo and were followed-up for between 24 and 62 months. Overall, 698 participants had a new fracture. The incidence of fractures did not differ between the groups.
The trial did not address whether supplementation should be used for primary prevention or for those who live in a care-home environment. The authors note that clarification of the role of supplementation in these settings awaits the results of other trials.
Professor Grant states: “Our trial indicates that routine supplementation with calcium and vitamin D3, either alone or in combination, is not effective in the prevention of further fractures in people who had a recent low-trauma fracture.
“Policies for secondary prevention should therefore consider other strategies. The main pharmacological intervention is antiresorptive drugs, such as bisphosphonates, which have rarely been assessed in patients who have not been taking calcium of vitamin D.”
In an accompanying Comment Philip Sambrook (Royal North Shore Hospital, Sydney, Australia) states: “Interpretation of the study is limited by two main factors. First, compliance with medication was only moderate. It declined to 63% after 2 years and might have been as low as 45% when non-responders to the questionnaire about compliance were included . . . Second, the study perpetuates the limitations of most previous studies by measuring 25-hydroxyvitamin D in only a small sample. Thus the vitamin D status of the trial population at baseline remains largely unknown, although, because the patients were younger than in other studies, ambulatory, and living in the community, they were less likely to have vitamin D deficiency.”