Healthy adults do not need to take vitamin D supplements, suggests a study in The Lancet which found they had no beneficial effect on bone density, a sign of osteoporosis. University of Auckland researchers analysed 23 studies involving more than 4,000 healthy people.
The New Zealand research team conducted a meta-analysis of all randomised trials examining the effects of vitamin D supplementation on bone mineral density in healthy adults up to July 2012. The trials took place in a number of different countries including the UK, the US, Australia, Holland, Finland and Norway.
Prof Ian Reid, lead study author, from the University of Auckland, said the findings showed that healthy adults did not need to take vitamin D supplements.
“Our data suggest that the targeting of low-dose vitamin D supplements only to individuals who are likely to be deficient could free up substantial resources that could be better used elsewhere in healthcare.”
Writing about the study in The Lancet, Clifford J Rosen from the Maine Medical Research Institute agrees that science’s understanding of vitamin D supports the findings for healthy adults, but not for everyone.
Dr Laura Tripkovic, research fellow in the department of nutritional sciences at the University of Surrey, said it was no good taking vitamin D supplements if people didn’t also maintain a healthy, balanced diet containing calcium and take plenty of exercise.
She said most healthy people should be able to absorb enough vitamin D naturally, through sunshine and diet. We get most of our vitamin D from sunlight on our skin, but it is also found in certain foods like oily fish, eggs and breakfast cereals.
However, taking too much vitamin D in the form of supplements can be harmful because calcium can build up and damage the kidneys.