Monday 8 May 2017

The role of vitamin B6 in the brain

We have previously reported that B vitamins can help to combat symptoms associated with schizophrenia, but B vitamins do much more for the brain. Below is an overview of the role of vitamin B6, a list of symptoms and an action plan.


We have previously reported that B vitamins can help to combat symptoms associated with schizophrenia, but B vitamins do much more for the brain. Although certain B vitamins have been researched more extensively than others, it is becoming increasingly clear that the entire complex of B vitamins play a crucial role in many brain processes. In this article, we start with vitamin B6.


Why don’t our bodies produce B vitamins?

Most B vitamins are produced by plants; an exception to this is vitamin B12, which is produced by bacteria, for example, in the intestines of ruminants. Nevertheless, the majority of people mainly obtain the small amount of B vitamins they take in from animal products, such as meat and milk. The animals that these B vitamins originate from have absorbed these themselves from organisms lower down in the food chain. But why don’t our bodies produce B vitamins?


Humans have lost the ability to produce certain vitamins themselves. The best-known example is vitamin C and in this respect we are similar to guinea pigs and bats. But we must also obtain all B vitamins from our food. Severe B vitamin deficiencies can lead to a whole range of disorders, the best known being beriberi (a B1 deficiency) and pellagra (a B3 deficiency). So how did we lose this ability? Surely producing this ourselves would protect us against deficiencies?


During our evolution, our food was always full of vitamins. Because of this, we ultimately lost the genes needed to, for example, produce vitamin B6. This was beneficial as it meant that our ancient ancestors did not have to perform novo synthesis (which required more energy than was absorbed from food) and caused oxidative stress in the body. But within our current physical environment, this evolutionary advantage is actually a disadvantage.


How our diet has changed

Our Paleo diet consisted of plants, fruit, nuts, fish, shellfish and seafood that contained high levels of vitamin B and, when this was available, meat. Today’s diet mainly consists of processed and red meat, margarine, dairy products, refined grains and sugars. Furthermore, the micronutrients have largely disappeared from these high-energy and easy to digest foods. This is where there is a link with the vitamin deficiencies often seen in the Western world, as well as the diseases of civilisation that we have to contend with, such as obesity, cardiovascular diseases and dementia. How do we address these?


The approach mainly concerns the diet. As well as a paleo diet, the Mediterranean diet is also associated with increased vitamin and mineral levels in the body. The Mediterranean diet mainly consists of fruit, vegetables, complex carbohydrates, olive oil, red wine, fish and white meat. Like the Paleo diet, it also provides more B vitamins than an average Western diet. Once again, an exception is B12, which is present in red meat and is therefore often eaten in sufficient amounts.


Nevertheless, there are many situations in which an increased need can arise, even when a Paleo or a Mediterranean diet is eaten. Risk groups for a vitamin B6 deficiency are the elderly, people with increased alcohol intake, smokers, women who are pregnant or who are breastfeeding and people who need more vitamin B6 because of the medication they take, stress, chronic inflammation or illness. The prevalence of B6 deficiencies in the population that do not take supplements is estimated at around 25 percent. Therefore, always consider whether supplementation is required.


What B vitamins do for our brain

B vitamins are involved in neurochemical synthesis and are therefore important for brain function. All B vitamins are also actively transported across the blood-brain barrier. B vitamins act as co-enzymes in many physiological processes in the body. A co-enzyme ensures that an enzyme works more efficiently. Take, for example, vitamin B6: in the bioactive P5P form, it is involved with more than 140 separate enzymes that are required for the production and breakdown of amino acids. But what brain-specific role does vitamin B6 have?


As a co-enzyme, vitamin B6 is involved in amino acid metabolism and is therefore a limiting factor in the production of neurotransmitters such as dopamine, serotonin, GABA, noradrenaline and melatonin. This means that even when there is a mild B6 deficiency, fewer neurotransmitters are produced. The production of GABA and serotonin then declines, which results in the behaviour not being regulated as well and sleeping disorders arise. Cardiovascular function and hormone production also decline, as well as the provision of glucose to the brain. But is this biochemical reasoning also supported by evidence from studies?


In a review performed in 2008, 77 studies were used, with data from a total of 34,000 participants. This revealed a clear correlation between brain function, mental health and the B6, B12 and folic acid levels in the blood. The higher the levels in the blood, the fewer problems with brain function, behaviour and mental health. This correlation also exists the other way around.


Identifying a vitamin B6 deficiency

Vitamin B6 deficiencies are common, which is why it is useful to be able to identify all symptoms. Below is a list of symptoms that could point to a (serious) vitamin B6 deficiency. The more symptoms present, the greater the chance that B6 is (one of) the culprit(s).


- fatigue

- cracks in the lips and corners of the mouth

- inflamed tongue and/or oral mucosa

- anaemia

- glucose intolerance

- nausea and vomiting

- seborrheic dermatitis

- fluid retention

- panic attacks

- hyperventilation

- migraine

- sleeplessness

- irritability

- confusion

- depression

- immunodeficiency

- chronic pain

- decline in cognitive capacity

- convulsions

- peripheral neuropathy

- ataxia

- elevated homocysteine levels

- elevated inflammatory activity (with an increase in C-reactive protein)

- elevated oxidative stress.


Measuring vitamin B6 in the blood

In consultation with your client, it has recently become possible to request fourteen different blood tests through Bonusan, from a simple iron test to full screening of the blood. One of these fourteen blood tests is the Blood Check Vitamin B6. This test will check the levels of vitamin B6 in the blood in nmol/l. But what constitutes a deficiency and what are the desired levels?


A total vitamin B6 level in the blood of higher than 40 nmol/l indicates that the vitamin B6 level is sufficient. A marginal vitamin B6 status (20-30 nmol/l) or vitamin B6 deficiency (<20 nmol/l) usually passes unnoticed, but over time can contribute to the occurrence of chronic illnesses. It is therefore very important to identify this deficiency at an early stage.


If, based on the aforementioned symptoms, you suspect a vitamin B6 deficiency, but you aren’t entirely sure or if you would like to know exactly how serious the deficiency is so that you can ensure that the therapy is properly aligned to this, request the Blood Check Vitamin B6 for your client.



  1. Kennedy D.O., B Vitamins and the Brain: Mechanisms, Dose and Efficacy – A review, Nutrients 2016, 8, 68, 28 January 2016.
  2. Morris M.S., Picciano M.F., Jacques P.F., Selhub J. Plasma pyridoxal 5′-phosphate in the us population: The national health and nutrition examination survey, 2003–2004. Am. J. Clin. Nutr. 2008;87:1446–1454.
  3. Smith A.D. The worldwide challenge of the dementias: A role for b vitamins and homocysteine? Food Nutr. Bull. 2008;29:S143–S172.