Vitamin D deficiency linked to higher dementia risk, study finds

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In a study from the University of South Australia, scientists found a direct link between dementia and a lack of vitamin D.

Dementia is the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person’s daily life and activities.

Some people with dementia cannot control their emotions, and their personalities may change.

Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of living.

Many factors may influence your risk of dementia, including genes, environment, and lifestyle.

In general, leading a healthy lifestyle may help address risk factors that have been associated with Alzheimer’s disease and related dementias.

Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects.

In humans, the most important compounds in this group are vitamin D₃ and vitamin D₂.

Previous research has found that higher vitamin D levels have beneficial effects on the brain.

In the current study, researchers aimed to examine the association between vitamin D levels in the body and the risk of dementia and stroke.

They used data from more than 75,000 adults in the UK Biobank database.

The team found vitamin D levels were linked to brain imaging results, such as gray matter, white matter, and hippocampal volumes.

Vitamin D levels had an inverse association with white matter hyperintensity volume. Vitamin D deficiency was linked to an increased risk of dementia and stroke, with the strongest associations for people with vitamin D levels lower than 25 nmol/L.

The team also confirmed the threshold effect of vitamin D levels on dementia, with the risk predicted to be 54% higher for participants at 25 nmol/L compared with 50 nmol/L.

Vitamin D level was not associated with brain imaging outcomes or the risk of stroke.

The team suggests 17% of dementia could be prevented by increasing vitamin D levels to 50 nmol/L.

Based on the findings, the team suggests that low vitamin D status was linked to worse neuroimaging outcomes and higher risks of dementia and stroke.

Further analyses support a causal effect of vitamin D deficiency on dementia but not on stroke risk.

The study was conducted by Professor Elina Hyppönen et al and published in The American Journal of Clinical Nutrition.

If you care about nutrition, please read studies that cranberries could help boost memory, and MIND diet could slow down cognitive decline after stroke.

For more information about nutrition, please see recent studies about antioxidants that could help reduce the risk of dementia, and how vitamin supplementation may affect the dementia risk.

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