Studie: Supplementierung mit Vitamin D könnte Demenz vorbeugen

Study: Vitamin D supplementation could prevent dementia

NUTRITIONAL NEWS Around every second person in Switzerland has a vitamin D deficiency, and the deficiency is particularly widespread among the older population. At the same time, over 150,000 people in Switzerland suffer from dementia, and around one in six deaths can be attributed to it. Research has already shown the causal connection between vitamin D deficiency and dementia. A new study now shows: Vitamin D supplementation could be the key to prevention.

In Switzerland , half of the population has a vitamin D value that is too low ; in Europe, the annual average is around 40 percent. Around 15 percent even have a serious deficiency. For older people, these values ​​are much higher (approx. 70% and 50%).

What is Vitamin D?
You can find out more here – and how vitamin D affects your sleep .

At the same time, over 55 million people worldwide are affected by dementia - and the trend is rising (139 million in 2050 according to the World Health Organization (WHO ). It is estimated that around 150,000 people with dementia live in Switzerland. Over 30,000 new cases are added every year (2022). 17.8 percent of annual deaths in this country are due to dementia.

Vitamin D plays an important role in the brain

Over the past decade, various studies have looked at the negative consequences of vitamin D deficiency, with a focus on non-skeletal diseases, i.e. not affecting the musculoskeletal system, but the brain. They suggested poorer cognitive abilities and a more than twofold increased risk of dementia and Alzheimer's disease .

A study by the University of South Australia published in 2022 was the first to prove a direct causal connection between dementia and vitamin D deficiency.

It turned out that chronic vitamin D deficiency is not only associated with smaller brain volume - the researchers also used genetic analyzes to find a causal connection between a deficiency in the sunshine vitamin and the development of dementia and strokes.

Supplementation can reduce risk

However, only a few studies have examined whether taking vitamin D supplements influences the risk of dementia. Until now: A new study published on March 1, 2023 from the University of Exeter (UK) and the University of Calgary (CA) found that people who supplemented with vitamin D had fewer dementia diagnoses than those who did didn't do.

“Overall, we found evidence that earlier supplementation could be particularly beneficial.”

Prof. Dr. Zahinoor Ismail

The researchers examined the connection in more than 12,388 participants from the US National Alzheimer's Coordinating Center, who were on average 71 years old and without dementia at the start of the study.

Over the course of 10 years, 2,696 participants developed dementia. Of these, 679 (25%) had taken vitamin D, compared to 2017 (75%) participants without vitamin D supplementation. With vitamin D supplementation, the incidence of dementia was 40 percent lower .

“We know that vitamin D has some effects in the brain that could have an impact on reducing dementia. Our results provide important insights into groups for which vitamin D supplementation may be particularly appropriate. Overall, we found evidence that earlier supplementation could be particularly beneficial, before the onset of cognitive decline," said lead researcher Prof. Zahinoor Ismail in the media release .

Vitamin D: Key to preventing dementia

A sufficient supply of vitamin D could be the key to prevention. “The association with vitamin D in this study suggests that taking vitamin D supplements could be beneficial in preventing or delaying dementia,” says study co-author Dr. Byron Creese .

Given the growing number of those affected, it is extremely important to prevent dementia or delay its onset. But clinical studies are now needed for this.

That's why research is continuing in Exeter. In an ongoing study, participants are randomly assigned to receive either vitamin D or a placebo to specifically examine changes in memory and thinking tests.


Facts and figures about dementia; Federal Office of Public Health BAG.

Dementia, Key Facts; WHO World Health Organization.

Vitamin D deficiency: data; Federal Office for Food Safety and Veterinary Affairs BLV.

Amrein, K., Scherkl, M., Hoffmann, M. et al. Vitamin D deficiency 2.0: an update on the current status worldwide. Eur J Clin Nutr 74, 1498–1513 (2020). DOI: 10.1038/s41430-020-0558-y

C. Balion, LE. Griffith, L. Strifler, et. al. Vitamin D, cognition, and dementia
(2012). DOI: 10.1212/WNL.0b013e31826c197f

D. Llewellyn et al.: Vitamin D and the risk of dementia and Alzheimer disease (2014). DOI: 10.1212 /WNL.0000000000000755

Navale SS, Mulugeta A, Zhou A, et al.: Vitamin D and brain health: an observational and Mendelian randomization study (2022). DOI: 10.1093/ajcn/nqac107

M. Ghahremani, EE Smith, H. Chen, B. Creese, Z. Goodarzi, Z. Ismail. Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, 2023; 15 (1) DOI: 10.1002/dad2.12404

Media release: University of Exeter. Taking vitamin D could help prevent dementia.

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