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Vitamin D deficiency increases the risk of dementia

Vitamin D deficiency increases the risk of dementiaDementia is on the rise across the globe but according to a study from University of South Australia, vitamin D may have the potential to pull the brake on the degenerative processes. The scientists have observed a direct link between the widespread problems with vitamin D deficiency and the increasing rate of dementia. At the same time, they assume that optimizing people’s vitamin D status in the blood may help prevent millions of dementia cases worldwide. The need for vitamin D varies from person to person, it should be noted, and many people have a higher need for the vitamin than what is officially recommended.

Dementia is a result of failing brain function and typically includes symptoms such as poor memory, trouble with managing simple tasks, difficulty with language or speech, confusion, and poor sense of direction. Also, drastic changes of mood and behavior may occur. Dementia can also be part of other diseases such as:

  • Alzheimer’s disease
  • Parkinson’s disease
  • Vascular dementia
  • Dementia with Lewy bodies
  • Frontotemporal dementia
  • Huntington’s disease

Ageing increases the risk of developing the different types of dementia. Type 2 diabetes increases the risk of vascular dementia and Alzheimer’s disease (that is also called type 3 diabetes). Stroke increases the risk of dementia later on in life. Most types of dementia progress slowly and patients often end up in nursing homes and die after several years.
An estimated 55 million people worldwide suffer from dementia with around 10 million new cases being diagnosed each year. Dementia is a huge burden to the individual patient and to society as such, which means there is every imaginable reason to prevent the disease. It is commonly known that diet and lifestyle play a major role, and researchers are now focusing on vitamin D.

Vitamin D’s role in brain health

Vitamin D is primarily known for its importance for bone health and the immune system. Still, the nutrient’s role in brain health has been described carefully through the last decades. The human brain has vitamin D receptors (VDR) in different parts. Here, vitamin D regulates different on-off-switches and various neurotransmitters. It also appears that vitamin D affects the hypothalamus, the part of the brain that is responsible for controlling blood sugar levels and body weight. Vitamin D also protects against oxidative stress and inflammation that may case atherosclerosis and damage to nerve cells and other tissues.

The link between vitamin D deficiency, brain volume, dementia, and stroke

The new study was conducted at the University of South Australia. The researchers analyzed data from around 300,000 participants, all of whom were registered in the UK Biobank. The scientists used new methods for conducting genetic analyses and found the following:

  • Having low levels of vitamin D in the blood is related to smaller brain volume and an increased risk of dementia and stroke
  • The genetic analyses supported a link between vitamin D and dementia
  • In some populations, up to 17 percent of dementia cases could be avoided by ensuring that everyone has vitamin D blood levels above 50 nmol/L

It has been difficult to prove vitamin D’s direct impact on brain health in earlier studies, and study results have been conflicting, which may be a result of using different analyzing methods. Nonetheless, the current study sheds new light on the importance of preventing and avoiding vitamin D deficiency, simply because the nutrient has the potential to prevent dementia and many other diseases. It appears that ensuring adequate blood levels of vitamin D is able to prevent millions of dementia cases worldwide. The new study is published in the American Journal of Clinical Nutrition.

How to optimize blood levels of vitamin D

Around one billion people globally are believed to lack vitamin D, mainly because of our modern lifestyle and too little sun exposure. Ageing processes, being dark-skinned, being overweight, and having diabetes all make it more difficult to synthesize and activate the nutrient in the body.
The Danish health authorities recommends for everyone to take a vitamin D supplement during the winter period, whereas old people and other vulnerable groups are advised to take a high-dosed vitamin D supplement all year round
The need for vitamin D varies from person to person. Still, everyone should ideally try to keep their blood levels of the vitamin above 50 nmol/L. Having levels between 75-120 nmol/L is even better. This would require getting more vitamin D than the official recommendations. There are high-dosed vitamin D supplements on the market that contain 20-100 micrograms of the nutrient. The best way to take vitamin D is in capsules where the vitamin is dissolved in oil for optimal bioavailability.


Shreeya S Navale, Anwar Mulugeta, Ang Zhou, David J Llewellyn, Elina Hyppönen. Vitamin D and brain health: an observational and Mendelian randomization study. The American Journal of Clinical Nutrition, 2022

University of Australia. Vitamin D deficiency can lead to dementia. ScienceDaily. June 14, 2022

Lingling lv et al. The relationships of vitamin D, vitamin D receptor gene polymorphisms, and vitamin D supplementation with Parkinson´s disease. Translational Neurodegeneration 2020

Alexander Muacevic and John R Adler: The Role of Vitamin D in Brain Health: A Mini Literature Review. Cureus 2018

Toshiharu Ninomiya. Epidemiological Evidence of the Relationship Between Diabetes and Dementia. Diabetes Mellitus. 2019

Endocrine Society. Vitamin D can lower weight, blood sugar via the brain, study finds. ScienceDaily 2014


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