While older people are often encouraged to take supplements containing vitamin D to help keep bones, teeth and muscles healthy, new research from the UK suggests there may actually be little to no health benefi
The study, published in the American Journal of Clinical Nutrition, also backs up previous data suggesting there is no gain for older people taking vitamin D.
“Vitamin D deficiency is common in older people, and it may lead to bone loss, impairment of muscle function and an increased risk of falls and fractures,” commented lead researcher Dr Terry Aspray from Newcastle University's Institute of Cellular Medicine, UK.
"The results from previous studies assessing the effect of vitamin D on bone mineral density have yielded conflicting results, and our study is a significant contribution to the current debate,” he added. "While our findings do not support evidence of the benefit of high dose vitamin D supplements, at least on bone mineral density, we do, however, identify that higher doses of the vitamin may have beneficial effects on bone metabolism and that they are safe for older people.”
Vitamin D research
Aspray and his colleagues looked at data from almost 400 people, aged 70 years or older, who were were randomly allocated to one of three doses of vitamin D given once a month for a year - the doses were 300 μg, 600 μg or 1200 μg (equivalent to a daily dose of 10 μg, 20 μg or 40 μg).
The study's aim - funded by UK charity Versus Arthritis - was to measure the effect of vitamin D supplementation on the change in bone mineral density (BMD), a recognised indicator of bone strength, and changers in markers of bone metabolism, in these older people.
The findings revealed that there was no change in BMD over 12 months between the three doses.
However, the study did show that doses equivalent to 40 μg a day are safe in an older population and there was a beneficial effect on bone metabolism up to the highest dose, said the team.
"Over the one year of this study, higher doses of vitamin D neither improved measures of bone strength nor reduced falls among older people,” noted Benjamin Ellis, Versus Arthritis Senior Clinical Policy Adviser.
He noted that while in the summer months vitamin D is manufactured by the body, dietary vitamin D from food and supplements remains important – and is especially important in winter months.
"The current guidance is still that people at risk of low vitamin D should consider taking a daily vitamin D supplement, as should everyone during the winter months,” said Ellis.
"Work is needed to implement effective strategies to prevent falls and fractures among older people, and to understand the role of medications and dietary supplements in this."
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1093/ajcn/nqy280
“Randomized controlled trial of vitamin D supplementation in older people to optimize bone health”
Authors: Terry J Aspray, et al