Vitamin D: Low levels ‘can double dementia risk’

Experts advise that supplements may protect ageing population from devastating brain illnesses

Science Editor

Low levels of vitamin D in elderly men and women can double the risk of developing dementia in later life according to one of the biggest studies of its kind into the nutritional supplement.

Senile dementia and Alzheimer’s disease were both significantly higher in people with low levels of vitamin D, compared to those with normal levels, when tested up to six years before the onset of symptoms, scientists found.

The findings suggest that taking vitamin D – which is also made by the skin when exposed to sunlight – could protect people against the onset of dementia, especially at northern latitudes where there are low levels of sunlight during winter months.

Some scientists have argued that vitamin D is actually a hormone rather than a vitamin and a deficiency should be treated more seriously than it is because of the increasing realisation that it is linked with a wide range of illnesses.

The latest study, published in the journal Neurology, monitored vitamin D levels in the blood of 1,659 people aged 65 and over who were free of dementia, cardiovascular disease and stroke at the time they were first tested.

Over the following six years, the scientists found that those who were moderately deficient in vitamin D were at 53 per cent higher risk of dementia, and a 69 per cent higher risk of Alzheimer’s disease, than those with normal levels of the vitamin.

In even more severely deficient people, the risk of dementia jumped to 125 per cent while there was a 122 per cent increased risk of developing Alzheimer’s disease – a dose-response finding showing that levels of vitamin D were a significant risk factor in both kinds of progressive brain illnesses.

“We expected to find an association between low vitamin D levels and the risk of dementia and Alzheimer’s disease, but the results were surprising – we actually found the association was twice as strong as we anticipated,” said David Llewellyn of the University of Exeter.

Previous research has established a link between low levels of vitamin D and the onset of cognitive problems but this study found confirmed a significant association with both dementia and Alzheimer’s disease.

“Clinical trials are now needed to establish whether eating foods such as oily fish or taking vitamin D supplements can delay or even prevent the onset of Alzheimer’s disease and dementia,” Dr Llewellyn said.

“We need to be cautious at this early stage and our latest results do not demonstrate that low vitamin D levels cause dementia. That said, our findings are very encouraging,” he said.

“Even if a small number of people could benefit, this would have enormous public health implications given the devastating and costly nature of dementia,” he added.

The number of people with dementia is expected to triple over the next half century as the population ages so even if a small number of people can benefit from taking vitamin D supplements, it will have a major impact on the costs of treating the illness, said Professor Gordon Wilcock of the University of Oxford.

“One could make a case for checking vitamin D levels in older people who have a poor diet, or who have little exposure to the sun, or alternatively as a part of an older persons’ routine screening programme, because vitamin D is important for other health reasons as well as memory problems and dementia,” Professor Wilcock said.

“Dementia is such a devastating disease that preventing or slowing down its progression, if this proves possible with vitamin D supplements, would be extremely important even if the number of people who benefited seems small,” he said.

Life and Style
ebookNow available in paperback
ebooks
ebookA delicious collection of 50 meaty main courses
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Recruitment Genius: Software Implementation Consultant

    £45000 - £50000 per annum: Recruitment Genius: This software company specialis...

    Recruitment Genius: Service Desk Co-ordinator / Client Services Administrator

    £22000 - £23000 per annum: Recruitment Genius: The successful applicant will s...

    Recruitment Genius: Sales & Warehouse Assistant

    £14807 - £15470 per annum: Recruitment Genius: This manufacturer and supplier ...

    Ampersand Consulting LLP: Security Consultant (CREST/CHECK/OSCP)

    £45000 - £65000 per annum + Benefits: Ampersand Consulting LLP: Security Consu...

    Day In a Page

    Giants Club: After wholesale butchery of Idi Amin's regime, Uganda’s giants flourish once again

    Uganda's giants are flourishing once again

    After the wholesale butchery of Idi Amin's regime, elephant populations are finally recovering
    The London: After 350 years, the riddle of Britain's exploding fleet is finally solved

    After 350 years, the riddle of Britain's exploding fleet is finally solved

    Archaeologists will recover a crucial item from the wreck of the London which could help shed more light on what happened in the vessel's final seconds
    Airbus has patented a jet that could fly from London to New York in one hour

    Airbus has patented a jet that could fly from London to New York in one hour

    The invention involves turbojets and ramjets - a type of jet engine - and a rocket motor
    10 best sun creams for kids

    10 best sun creams for kids

    Protect delicate and sensitive skin with products specially formulated for little ones
    Tate Sensorium: New exhibition at Tate Britain invites art lovers to taste, smell and hear art

    Tate Sensorium

    New exhibition at Tate Britain invites art lovers to taste, smell and hear art
    Ashes 2015: Nice guy Steven Finn is making up for lost time – and quickly

    Nice guy Finn is making up for lost time – and quickly

    He was man-of-the-match in the third Test following his recall to the England side
    Ashes 2015: Remember Ashton Agar? The No 11 that nearly toppled England

    Remember Ashton Agar?

    The No 11 that nearly toppled England
    Turkey-Kurdish conflict: Obama's deal with Ankara is a betrayal of Syrian Kurds and may not even weaken Isis

    US betrayal of old ally brings limited reward

    Since the accord, the Turks have only waged war on Kurds while no US bomber has used Incirlik airbase, says Patrick Cockburn
    VIPs gather for opening of second Suez Canal - but doubts linger over security

    'A gift from Egypt to the rest of the world'

    VIPs gather for opening of second Suez Canal - but is it really needed?
    Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

    Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

    Fashion editor, Alexander Fury, applauds a man who clearly has more important things on his mind
    The male menopause and intimations of mortality

    Aches, pains and an inkling of mortality

    So the male menopause is real, they say, but what would the Victorians, 'old' at 30, think of that, asks DJ Taylor
    Man Booker Prize 2015: Anna Smaill - How can I possibly be on the list with these writers I have idolised?

    'How can I possibly be on the list with these writers I have idolised?'

    Man Booker Prize nominee Anna Smaill on the rise of Kiwi lit
    Bettany Hughes interview: The historian on how Socrates would have solved Greece's problems

    Bettany Hughes interview

    The historian on how Socrates would have solved Greece's problems
    Art of the state: Pyongyang propaganda posters to be exhibited in China

    Art of the state

    Pyongyang propaganda posters to be exhibited in China
    Mildreds and Vanilla Black have given vegetarian food a makeover in new cookbooks

    Vegetarian food gets a makeover

    Long-time vegetarian Holly Williams tries to recreate some of the inventive recipes in Mildreds and Vanilla Black's new cookbooks