Osteoporotic fractures are a major and growing healthcare problem in many industrialised societies. An epidemiological study of fracture data between 1988 and 1998 for England and Wales found that one in two women and one in five men over the age of 50 had suffered a fracture.1 Most of these fractures would have occurred after low-energy trauma, such as a fall from standing height or less, in bone weakened by osteoporosis. Of the fractures primarily associated with osteoporosis, hip fracture is the most disabling and is often fatal. Mainly old (mean age ∼80 years), female (∼80% are women) and often frail people sustain hip fractures. Characteristically such people have insufficient vitamin D, which is a key agent for building bone. An update of a comprehensive systematic review that examines the effects of vitamin D and vitamin D analogues for preventing osteoporotic fractures in older people has been published in the Cochrane Database of Systematic Reviews.2

This review by Avenell and colleagues includes 45 trials, of which, 42 were individually randomised trials, one was a …