Brains that have higher levels of vitamin D show better cognitive function, a new study suggests.
Scientists have said that the research, which looked at vitamin D levels in adults who suffered from varying rates of cognitive decline, could help them further understand dementia and its causes.
They say the study is the first to examine levels of vitamin D in brain tissue.
An estimated 55 million people in the world have dementia, with the number expected to increase.
In light of this, researchers want to better understand what causes the condition in order to develop treatments to slow or stop the disease.
The study, conducted by researchers at Tufts University in the US, found that people who had higher levels of vitamin D in their brains had better cognitive function.
Senior author Sarah Booth, director of the Jean Mayer USDA Human Nutrition Research Centre on Ageing (HNRCA) 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 other related dementias.”
Previous studies have shown that vitamin D supports a number of bodily functions, including immune responses and maintaining healthy bones.
The vitamin can be found in fatty fish and fortified drinks such as milk or orange juice. Brief exposure to sunlight also provides people with a dose of vitamin D.
In the autumn and winter, the NHS recommends that people take a daily supplement containing 10mg of vitamin D to boost levels.
The researchers, however, have warned people against taking large doses of it as a preventive measure.
The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, saw researchers examining samples of brain tissue from 209 people in the Rush Memory and Ageing Project.
The project is a long-term study of Alzheimer’s disease that began in 1997.
High levels of vitamin D in four specific regions of the brain correlated with better cognitive function.
Two of the four regions of the brain examined by researchers are associated with changes linked to Alzheimer’s while one is associated with forms of dementia linked to blood flow, and one without any known associations with cognitive decline related to Alzheimer’s or vascular disease.
However, the levels of vitamin D in the brain did not associate with any of the physiological markers associated with Alzheimer’s in the brain studied, including amyloid plaque build-up, Lewy body disease, or evidence of chronic or microscopic strokes.
Scientists said that it remains unclear how exactly vitamin D might affect brain function.
Kyla Shea, the lead author of the study and associate professor at the Friedman School of Nutrition Science and Policy at Tufts, said: “We now know that vitamin D is present in reasonable amounts in human brains, and it seems to be correlated with less decline in cognitive function.
“But we need to do more research to identify the neuropathology that vitamin D is linked to in the brain before we start designing future interventions.”
Additional reporting by PA
