Few people realise that vitamin D acts more like a brain fat than a vitamin – and your risk of cognitive decline can soar by up to 19 times if your levels are low. Often known as the sunshine vitamin, it is in fact a vital brain nutrient: helping neurons communicate, calming inflammation and defending against oxidative stress – all crucial for protecting memory, mood and long-term cognitive health. This highlights the important connection between vitamin D and dementia.
When vitamin D levels drop, the effects on the brain are striking.
Studies show that people with low vitamin D are far more likely to experience cognitive decline and dementia, while those with optimal levels have up to four times lower risk of developing Alzheimer’s disease. In older adults, falling vitamin D often mirrors worsening memory – yet the simple act of supplementing can reduce risk by a third. (That is why we offer our DRIfT at-home blood tests so you can know your levels are optimal and protect your brain.)
Read on to discover why optimising your vitamin D intake – and measuring it alongside other key brain biomarkers – could be one of the most powerful steps you can take to future-proof your brain.
Low vitamin D levels are significantly linked to a higher risk of dementia and cognitive decline. [1,2,3] One notable study carried out in France highlights an astonishing finding: older women with vitamin D deficiency were approximately 19 times more likely to develop dementia within seven years compared to those without vitamin D deficiency. [4] This research backs up several previous studies, including one that tracked 1,658 elderly adults for over five and a half years [5], concluding:
“Vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer’s disease.”
With more than 50 million people around the world affected by dementia, a figure forecast to triple by 2050, [6]) research into prevention is something that Food for the Brain takes seriously. Our Research Team is currently undertaking an independent study, commissioned by Dr William Grant, led by Tommy Wood, Assistant Professor at the University of Washington, Seattle, and supported by Simona Brucoli, data statistician. This research aims to contribute to the growing knowledge of the importance of Vitamin D in preserving brain health and staving off cognitive decline. More on this later in the year!
The impact of Vitamin D deficiency is a significant one, with links to not only dementia but also conditions such as osteoporosis, cardiovascular disease, cancer, stroke, diabetes, schizophrenia, psychosis, and autism [7], as well as behavioural problems in adolescents [8] and children with ADHD (9). Read more on how deficiency in Vitamin D impacts our overall health in our article here.
Of course, we can get vitamin D from our diet: oily fish, including salmon, mackerel, sardines, egg yolks, red meat, and liver, are all excellent sources. However, our bodies struggle to produce and maintain optimal vitamin D levels as we age, even with a good diet.
Our reliance on the sun, our natural provider of Vitamin D, is also compromised, especially in the Northern Hemisphere, as we begin to emerge from the long winter months and not, as yet, fully into the bright embrace of summer. It’s no wonder that our bodies are left vulnerable to notable decreases in vitamin D.
Deficiency is defined as serum 25(OH)D concentrations of less than 50 nmol/L. Our vitamin D expert, Dr William Grant, says:
“All the evidence regarding cardio-metabolic diseases, cancer, diabetes, infectious diseases, and pregnancy outcomes shows that you need a blood level of vitamin D above 75 nmol/L to be healthy, and the same is proving true for the brain.”
This optimal level is impossible to achieve without supplementation in the winter. I recommend every adult and teenager supplements themselves with at least 1000 to 3000iu per day from October to March in line with a recent review by 35 vitamin D researchers. [10] The degree of obesity [11], darker skin colour [12] and living further North [13] increases need.
According to recent research, turning to vitamin D supplements could reduce the risk of dementia. Researchers at the University of Calgary’s Hotchkiss Brain Institute in Canada and the University of Exeter in the UK explored the relationship between vitamin D supplementation and dementia in 12,388 participants with a mean age of 71. They were dementia-free when they signed up. Of the group, 37 percent (4,637) took vitamin D supplements. In the study, the team found that taking vitamin D was associated with living dementia-free for longer, and they also found 40 percent fewer dementia diagnoses in the group who took supplements. [10]
The answer lies in taking a proactive step: testing your vitamin D levels.
Here at Food for the Brain, we don’t believe in guesswork. We champion the idea that we are all the architects of our own brain health and well-being. In the spirit of Citizen Scientists, we offer our accurate at-home blood tests so you can feel confident that you are protecting your mood, memory and future. Order your blood test here – available globally.
Awareness is the first step toward meaningful change. Discovering your vitamin D level is more than just informative; it’s a critical step toward optimising your cognitive and physical health.
Encourage your family and friends to check their brain health and vitamin D levels too – prevention starts with awareness.
Take our quick, scientifically validated Cognitive Function Test to see how your brain is performing right now. It’s free, is validated and gives you a personalised Dementia Risk Index and tailored advice.
Order our DRIfT 5-in-1 at-home blood test to measure the five key markers that matter most — Vitamin D, Homocysteine, HbA1c, Glutathione and Omega-3. Your results come with clear guidance on how to optimise each one.
Food for the Brain is a non-for-profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index to be able to advise you on how to dementia-proof your diet and lifestyle.
By completing the Cognitive Function Test you are joining our grassroots research initiative to find out what really works for preventing cognitive decline. We share our ongoing research results with you to help you make brain-friendly choices.
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