Brain health and Vitamin D deficiency: How it can increase the risk of dementia and what to do about it

Dementia is one of the leading causes of disability, reduced life quality, and dependency among older adults globally. This is a progressive neurological condition that affects cognitive functions, such as memory and thinking, and worsens over time, interfering with daily activities. Alzheimer's disease is the most common form of dementia. But what if you could prevent this degenerative condition, before it even buds?A study led by researchers from the University of South Australia found a direct link between dementia and a lack of vitamin D. The findings of the research are published in the American Journal of Clinical Nutrition. What is vitamin D Vitamin D, often known as the ‘sunshine vitamin’, is an essential nutrient that helps to absorb calcium to build and maintain strong bones and teeth, and supports immune, nerve, and muscle function. Our body can produce vitamin D naturally when exposed to sunlight. Dietary sources include animal-based foods like fatty fish, egg yolks, and fortified dairy. Vitamin D deficiency and dementia Dementia, which is a chronic or progressive syndrome, leads to deterioration in cognitive function. 57 million people had dementia worldwide in 2021, according to the World Health Organization (WHO). Nearly 10 million new cases are reported every year. The 2022 study by University of South Australia researchers found that low levels of vitamin D were associated with lower brain volumes and an increased risk of dementia and stroke.The study, supported by the National Health and Medical Research Council, analysed data from 294,514 participants from the UK Biobank. The study aimed to understand the impact of low levels of vitamin D (25 nmol/L) and the risk of dementia and stroke. “Vitamin D is a hormone precursor that is increasingly recognised for widespread effects, including on brain health, but until now it has been very difficult to examine what would happen if we were able to prevent vitamin D deficiency. Our study is the first to examine the effect of very low levels of vitamin D on the risks of dementia and stroke, using robust genetic analyses among a large population,” Professor Elina Hyppönen, senior investigator and Director of UniSA’s Australian Centre for Precision Health, said in a statement. Hyppönen added that these findings are important for the prevention of dementia.“In some contexts, where vitamin D deficiency is relatively common, our findings have important implications for dementia risks. Indeed, in this UK population, we observed that up to 17 per cent of dementia cases might have been avoided by boosting vitamin D levels to be within a normal range,” Professor Hyppönen added. “Dementia is a progressive and debilitating disease that can devastate individuals and families alike. If we’re able to change this reality through ensuring that none of us is severely vitamin D deficient, it would also have further benefits, and we could change the health and well-being for thousands. Most of us are likely to be ok, but for anyone who, for whatever reason, may not receive enough vitamin D from the sun, modifications to diet may not be enough, and supplementation may well be needed,” Prof Hyppönen concluded.