NUTRITIONAL NEWS Around every second person in Switzerland has a vitamin D deficiency, and the deficiency is particularly widespread among the elderly. 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 link between vitamin D deficiency and dementia. A new study now shows that supplementing with vitamin D could be the key to prevention.
In Switzerland , half of the population has too low a vitamin D level ; the European average is around 40 percent per year. Around 15 percent even have a serious deficiency. In older people, these values are even higher (around 70% and 50%).
What is vitamin D?
Find out more here – and how vitamin D affects your sleep .
At the same time, more than 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 examined the negative consequences of vitamin D deficiency, focusing on non-skeletal diseases, i.e. diseases affecting the brain rather than the musculoskeletal system. They indicate poorer cognitive abilities and a more than twofold increased risk of dementia and Alzheimer's disease .
A study published in 2022 by the University of South Australia was the first to prove a direct causal link between dementia and vitamin D deficiency.
It was shown that chronic vitamin D deficiency is not only associated with a smaller brain volume - with the help of genetic analyses, the researchers also found a causal link between a deficiency of the sunshine vitamin and the development of dementia and strokes.
Supplementation can reduce risk
However, few studies have examined whether taking vitamin D supplements affects the risk of dementia. Until now: A new study published on March 1, 2023 by the University of Exeter (UK) and the University of Calgary (CA) found that people who supplemented vitamin D were less likely to be diagnosed with dementia than those who did not.
"Overall, we found evidence that earlier supplementation may be particularly beneficial."
Prof. Dr. Zahinoor Ismail
The researchers examined the association in more than 12,388 participants from the US National Alzheimer's Coordinating Center who were on average 71 years old and did not have 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 2,017 (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 may impact on reducing dementia. Our results provide important insights into groups for whom vitamin D supplementation may be particularly suitable. Overall, we found evidence that earlier supplementation may be particularly beneficial, before the onset of cognitive decline," said lead researcher Prof. Zahinoor Ismail in the press release .
Vitamin D: Key to Preventing Dementia
An adequate supply of vitamin D could therefore 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 people affected, it is of utmost importance to prevent dementia or delay its onset. However, this now requires clinical studies.
That is why research is continuing in Exeter. In an ongoing study, participants are randomly assigned to receive either vitamin D or a placebo in order to specifically examine the changes in memory and thinking tests.
Sources:
Figures & facts about dementia; Federal Office of Public Health BAG. https://www.bag.admin.ch/bag/de/home/zahlen-und-statistiken/zahlen-fakten-demenz.html
Dementia, Key Facts; WHO World Health Organization. https://www.who.int/news-room/fact-sheets/detail/dementia
Vitamin D deficiency: data situation; Federal Office for Food Safety and Veterinary Affairs BLV. https://www.blv.admin.ch/blv/de/home/das-blv/organisation/kommissionen/eek/vitamin-d-mangel.html
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. https://news.exeter.ac.uk/research/taking-vitamin-d-could-help-prevent-dementia-study-finds