A Common Vitamin May Help Boost Brain Function In People At Higher Risk Of Dementia

Vitamin D deficiency has long been associated with a higher risk of dementia, though that link doesn’t necessarily prove that lower levels of the nutrient definitely cause the condition. 

But some scientists have noticed higher levels of tau – a protein whose “tangled” buildup in the brain has been linked to dementia  – among those who had lower vitamin D levels in their 30s and 40s.

And now, a paper published in Sleep Medicine has found that people who took high levels of vitamin D while exhibiting two early dementia signs performed 13% better on cognitive tests than those without the symptoms, who didn’t supplement with the vitamin. 

People at “high risk” of dementia seemed to perform better after taking vitamin D

Researchers identified people with both mild cognitive impairment (MCI), which is often seen as a precursor to dementia, and sleep disturbances, which are also linked to the condition. 

So, the 54 participants with both symptoms were deemed a “high-risk group that may be more vulnerable to progression toward[s] [Alzheimer’s]” in this paper. 

Members of this group who reported taking high doses of vitamin D daily performed 13% better on the Montreal Cognitive Assessment (MoCA), a memory and thinking test often deployed as a dementia risk screening tool, than those who didn’t. 

That’s despite the fact that all people who were studied in this research had both dementia-related symptoms. The finding stood after adjusting for other factors, too – and the type of vitamin D (D3 or D2) didn’t seem to matter.

Timing might matter

Though they were considered at high risk of dementia, none of the participants in this study had actually been diagnosed with it. 

MCI has been described as an “intermediate stage between normal cognitive ageing and dementia”, and might therefore “represent an important window” in which experts could step in to improve symptoms.

Speaking to Emory News, Emory University’s Associate Professor Victoria Pak said: “In older adults experiencing both sleep disturbance and mild cognitive impairment, this may represent a critical window for intervention, when cognitive changes are emerging, but opportunities to support brain health may remain. 

“Identifying accessible and modifiable factors, such as vitamin D supplement intake, during the earlier stages of cognitive decline may become increasingly important, particularly as rates of Alzheimer’s disease continue to rise”. 

Speak to your doctor before taking high levels of vitamin D

The participants in this study actually took more vitamin D (5,000 IU daily) than the NHS says is the max safe limit (4,000 IU). 

Taking too much vitamin D can cause hypercalcaemia, which happens when there’s too much calcium in your blood. It can affect your heart, brain, bones, and kidneys.

So, even though vitamin D deficiency is believed to affect about one in six UK adults, you won’t know for sure if you’re affected without having your blood tested – and you should certainly speak to your doctor about supplementation if you have other medical conditions. 

Don’t go over the recommended limit without expert advice.