By ‘Dr. Naomi Newman-Beinart (PhD), health expert and nutritionist (BSc)

More and more studies have looked at the links between dementia and vitamin B12 over the past 10- 15 years, and many of them come to the conclusion that lower levels of serum B12 appear to be associated with a faster rate of cognitive decline (1 – 3). 

Why does this happen and what are some symptoms of B12 deficiency? 

Well, as we age, our ability to absorb nutrients like B12 reduces and research shows that around 20% of adults over 60 in the UK may be B12 deficient (4). When someone is deficient in vitamin B12, not enough red blood cells will be produced, which means that oxygen cannot be carried around the body properly. This can lead to problems with memory, vision, and muscle weakness, to name just a few symptoms of B12 deficiency.

Some of the key signs of B12 deficiency include fatigue, difficulty concentrating, mouth ulcers, pins and needles in hands and feet, low mood, and weakness. 

This essential vitamin is a water-soluble B vitamin, and although a varied and balanced diet should provide much of your vitamin and mineral intake, many people struggle to get the recommended daily allowance (RDA) of B12 for a number of reasons, including increasing age, eating a poor or limited diet, malabsorption due to drinking too much alcohol or gut problems, and having certain medical conditions or medications.

What does the research say?

B12 is vital for brain health and all of your brain’s processes, including memory and cognition. Researchers have found that the size of your brain may shrink when you become B12 deficient, which might explain why people’s cognitive abilities are affected due to B12 deficiency (5). What is really interesting about B12 research is that studies have now found that taking certain B vitamins, including B12, may reduce the rate in which our brain’s shrink as we get older. Shrinking of the brain is part of the natural process of aging, however, the rate of shrinkage is faster in people over 70 with mild memory problems, and even faster in people with Alzheimer’s Disease. Some scientists have found that vitamin B12 can improve brain function in older people with vitamin B12 deficiency whether they have dementia or not (6). So clearly B12 is vital for supporting a healthy brain!

Can you reduce your risk of developing dementia?

According to the NHS, you CAN reduce your risk of developing dementia as you get older by living a healthy lifestyle (7). This can also reduce the risk of developing cardiovascular diseases, which are risk factors for the two most common types of dementia, Alzheimer’s disease and vascular dementia (7). So it seems that anything that is good for heart health is also good for brain health. Recent research in The Lancet suggests that 4 in 10 cases of dementia could be prevented if more people modified their lifestyle to be more healthy (8). For example, by stopping smoking, reducing alcohol consumption, exercising regularly, eating a balanced diet, and maintaining a healthy weight. 

How can you make sure you get B12 from your diet? 

Well, this is far easier for people who eat animal products, such as meat, fish and dairy. However, even if you are eating the right foods, Vitamins B12 is notoriously hard to absorb. Also, B12 can be difficult to find if you are vegetarian or vegan. Some vegan foods and drinks are fortified with B12, and you can find some in vegan foods like nori and nutritional yeast. However, research shows that our B12 needs cannot be met from vegetarian / vegan sources alone (9).

So, what can you do to make sure you are getting enough B12? Since your body can’t make B12, I always recommend a good quality B12 spray. BetterYou Vitamin B12 oral spray – £12.45 for 48 doses, available from Amazon, health stores and It tastes of raspberry and uses the most bio-available form of B12 (methylcobalamin) which is a naturally active form found within human metabolism. It is really easy to use and can be applied directly onto the inner cheek of the mouth. Absorption happens immediately! It’s fast, it’s convenient and it tastes great.

An important note to remember is that long-term B12 deficiency can lead to B12 anaemia (pernicious anaemia) if not treated soon enough, so always see your GP if you think you may be B12 deficient.

  1. Tangney, C. C., et al, Biochemical Indicators of B-12 and Folate Insufficiency and Cognitive Decline, Neurology; Vol. 72, No. 4, pgs 361-367: 2009.