Taking vitamin D pills does not strengthen bones or stop fractures, researchers claimed last night.
UK health chiefs have previously advised adults and children to consider taking vitamin D supplements over winter to avoid bone problems.
But a new major study said the pills do not prevent fractures or improve bone mineral density.
The authors, who combined the results of 81 previous studies, said there is ‘little justification’ in recommending the supplements to maintain or improve musculoskeletal health.
UK health chiefs had previously told adults and children to try to take the vitamins
The report said the sole advantage of taking vitamin D was to reduce the risk of rare conditions such as rickets and osteomalacia, but only in high-risk groups of people who get little sunlight exposure.
Lead author Dr Mark Bolland, of the University of Auckland in New Zealand, said: ‘Our meta-analysis finds that vitamin D does not prevent fractures, falls or improve bone mineral density, whether at high or low dose. Clinical guidelines should be changed to reflect these findings.’
But other experts questioned the relevance of the findings. They insisted the new study included very few people whose vitamin D levels were too low before they took the pills.
Vitamin D is made naturally by the human body when skin is exposed to the sun.
But Britain’s gloomy weather in the autumn and winter – and our indoor lifestyles – mean most people have to rely on their diet to get enough of the vitamin.
They can do that by eating liver, eggs, red meat and oily fish – but millions of Britons do not have enough of these foods. Experts believe a fifth of people in Britain have vitamin D levels that are too low. This puts them at risk of broken bones and is thought to affect brain and heart development in babies. It can lead to respiratory infections among adults.
A new study said the pills do not prevent fractures or improve mineral density
Official advice from Public Health England is that adults and children over the age of one should ‘consider taking a daily supplement containing 10 micrograms of vitamin D, particularly during autumn and winter’. It adds: ‘People who have a higher risk of vitamin D deficiency are being advised to take a supplement all year round.’
The advice is designed to ‘protect musculoskeletal health’.
Dr Robert Clarke, of the University of Oxford, said of the new study: ‘The report included all available trials of vitamin D, but such trials included too few participants, used an insufficient dose of vitamin D, and had an insufficient duration of treatment. So it is too soon to suggest making changes to health recommendations on vitamin D for bone health based on this study.
‘We should wait until the results of the five ongoing trials of vitamin D, involving 57,000 adults, that will be available in the next year or so.’ Professor Adrian Martineau, of Queen Mary University of London, added: ‘A major limitation of this study is that people with low vitamin D levels – who potentially stand to benefit the most from supplementation – were in a small minority in the trials included in the analysis.
Professor Louis Levy, of PHE, said: ‘During autumn and winter, those not consuming foods naturally containing or fortified with vitamin D should consider a 10 microgram supplement.’
The new study was published in the Lancet Diabetes & Endocrinology journal.