Study shows vitamin D supplements are of no benefit to
the over 70s
Dr Terry Aspray
Older people are often
encouraged to take supplements of vitamin D to keep bones, teeth and muscles
healthy.
But a Newcastle
University-led study, published in the American Journal of Clinical
Nutrition, has backed previous research which shows there is
no gain for older people taking vitamin D.
Almost 400 people, aged
70 years or older, 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 Versus
Arthritis - was to measure in these older people 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.
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.
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.
Dr Terry Aspray, Honorary Clinical Senior
Lecturer at Newcastle University’s Institute of Cellular Medicine, who is
supported by the NIHR Newcastle Biomedical Research Centre,
led the Vitamin D supplementation in older people study (VDOP).
He said: “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.
“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.
“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.
“I would suggest that
older people should focus on maintaining a healthy, balanced diet, adequate sun
exposure and take regular exercise to keep their bones as strong as possible.
“While some may need to
take vitamin D supplements, there is little benefit to taking more than 10 µg a
day.”
Further analysis is
underway, including by a Newcastle University PhD student, on the effects sun
exposure on vitamin D levels in older people and the impact of vitamin D
supplements on muscle strength.
Experts are also looking
at the impact of genes and kidney function on vitamin D levels and their
function in the blood.
Benjamin Ellis, Versus
Arthritis Senior Clinical Policy Adviser, said: “Older people
are at increased risk of falls and fractures, which are debilitating and erode
people’s self-confidence, depriving them of their independence.
“Vitamin D helps build
and maintain strong bones and muscles. People who are deficient in vitamin D
are at increased risk of falls and fractures.
“In the summer months,
Vitamin D is manufactured by the body when sunlight falls on the skin. We can also
get vitamin D from certain foods, or dietary supplements.
“Over the one year of
this study, higher doses of vitamin D neither improved measures of bone
strength nor reduced falls among older people.
“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.
“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.”
Reference
Terry J Aspray et al.
American Journal of
Clinical Nutrition.
Doi: 10.1093/ajcn/nqy280
