Vitamin D ‘may cut dementia risk by a third’

‘Sunshine vitamin’ present in larger amounts in brains that had better cognitive function, researchers find

TAKING vitamin D may reduce individuals’ risk of dementia by up to a third, a study suggests.

Researchers at Tufts University in the US looked at the levels of vitamin D – the sunshine vitamin – of 290 adults taking part in the Rush Memory and Ageing Project, a long-term study of Alzheimer’s that began in 1997.

The team looked at vitamin D levels in four regions of the brain, two linked to Alzheimer’s, one known to be involved in dementia and another believed to not be linked to age-related cognitive decline.

They found that it was present in all of the regions and those with more of it had better cognitive function. “Higher brain concentrations were associated with 25 per cent to 33 per cent lower odds of dementia or mild cognitive impairment at the last visit before death,” the scientists concluded.

However, the levels of vitamin D in the brain were not associated with physiological markers – such as amyloid plaque build-up, Lewy body disease, or evidence of chronic or microscopic strokes – seen in the brains of Alzheimer’s sufferers examined after death.

The scientists said: “Additional research is needed to clarify the specific mechanisms underlying this potentially protective relationship” and that more work was needed to fully understand the role of vitamin D in the brain and the potential extent of its protective effect.

It is estimated that some 55million people worldwide suffer from dementia and researchers are seeking to understand what causes the condition to develop treatments to slow or stop the disease. Fatty fish, milk and orange juice contain vitamin D, and brief exposure to sunlight also provides a dose.

Sarah Booth, senior author and director of the Jean Mayer USDA Human Nutrition Research Centre on Ageing at Tufts, said: “This research reinforces the importance of studying how food and nutrients create resilience to protect the ageing brain against diseases such as Alzheimer’s disease and related dementia.”

However, the researchers warn, large doses of the vitamin should not be taken as a preventive measure. The NHS recommends that during the autumn and winter, everyone (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10 micrograms of the vitamin.

The findings are published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

‹A study of half a million Britons found that more than half (57 per cent) of Asians were “severely deficient” in vitamin D during the darker months of winter and spring. The proportion falls to 51 per cent in the summer. For black people, the figure was 38.5 per cent for the darker months and 30.8 per cent at lighter times of year.