Taking this one vitamin could help prevent dementia in women, study finds

A promising discovery

Cognitive decline is something that threatens the well-being of all Australians as we age, but one new study has found a promising correlation between brain longevity and a popular vitamin. 

What if it was possible to prevent the onset of some of the most debilitating diseases by simply popping a pill? While we’re still a few medical advancements away from that reality, researchers behind a new study suggest it might not be a completely farfetched idea.  

According to the findings of a US observational study published in Alzheimer's & Dementia, adults who increase their intake of vitamin D may lower their risk of developing dementia by up to 40 per cent. 

Details of the study

Analysing the National Alzheimer's Coordinating Center data of roughly 12,400 older adults with an average age of 71, scientists compared the cognitive function and decline of the participants with varying intake levels of vitamin D. 

At their baseline evaluation, all participants were classified as dementia-free, but given one of two cognitive diagnoses: Normal cognition and Mild cognitive impairment. 

The participants were also split into two groups, one having taken a combination of up to three types of vitamin D supplements prior to their baseline exam, and one having not. 

Based on the findings of past studies that attribute an increased risk of dementia to vitamin D deficiency, this observational study aimed to highlight positive cognitive health outcomes as a result of increasing vitamin D intake – especially in women. 

The study highlights positive cognitive health outcomes as a result of increasing vitamin D intake. Image: iStock

The influence of vitamin D on cognitive decline

Overall, increased vitamin D exposure was found to be associated with a 40 per cent lower dementia incidence rate in the participants who were regularly exposed. The five-year survival rate for the group exposed to vitamin D was also found to be 15 per cent higher than the group of participants who did not take vitamin D. 

Remarkably, while more women in the study were considered to have a higher risk of developing dementia than men they also responded to increased vitamin D intake 23 per cent better than their male counterparts. Women with vitamin D exposure showed a 49 per cent lower incidence rate than women with no exposure.

Of all participants across the board, 75 per cent of those who developed dementia over 10 years had no exposure to vitamin D before their diagnosis. 

Unsurprisingly, participants with normal cognition at baseline had a lower dementia incidence rate than participants with MCI. 

Individuals classified as having Mild cognitive impairment at their baseline evaluation but given regular vitamin D exposure were found to have a 33 per cent lower incidence of dementia than those without vitamin D exposure. A similar incidence decrease was also seen in vitamin D-exposed participants carriers of the APOE ε4 gene (a biomarker for Alzheimer's disease). 

Originally published as Taking this one vitamin could help prevent dementia in women, study finds