Scientists at the University of Reading measured the impact of high doses of Vitamin B6 on young adults and found that they reported feeling less anxious and depressed after taking the supplements every day for a month.
The study, published in the journal Human Psychopharmacology: Clinical and Experimental, provides valuable evidence to support the use of supplements thought to modify levels of activity in the brain for preventing or treating mood disorders.
Dr David Field, lead author from the School of Psychology and Clinical Language Sciences at the University of Reading, said: The functioning of the brain relies on a delicate balance between the excitatory neurons that carry information around and inhibitory ones, which prevent runaway activity.
Recent theories have connected mood disorders and some other neuropsychiatric conditions with a disturbance of this balance, often in the direction of raised levels of brain activity.
Vitamin B6 helps the body produce a specific chemical messenger that inhibits impulses in the brain, and our study links this calming effect with reduced anxiety among the participants.
The new study focused on the potential role of Vitamins B6, which is known to increase the body's production of GABA (Gamma-Aminobutyric Acid), a chemical that blocks impulses between nerve cells in the brain.
In the current trial, more than 300 participants were randomly assigned either Vitamin B6 or B12 supplements far above the recommended daily intake (approximately 50 times the recommended daily allowance) or a placebo, and took one a day with food for a month.
The study showed that Vitamin B12 had little effect compared to placebo over the trial period, but Vitamin B6 made a statistically reliable difference.
Raised levels of GABA among participants who had taken Vitamin B6 supplements were confirmed by visual tests carried out at the end of the trial, supporting the hypothesis that B6 was responsible for the reduction in anxiety. Subtle but harmless changes in visual performance were detected, consistent with controlled levels of brain activity.
Dr Field said: "Many foods, including tuna, chickpeas and many fruits and vegetables, contain Vitamin B6. However, the high doses used in this trial suggest that supplements would be necessary to have a positive effect on mood"
It is important to acknowledge that this research is at an early stage and the effect of Vitamin B6 on anxiety in our study was quite small compared to what you would expect from medication. However, nutrition-based interventions produce far fewer unpleasant side effects than drugs, and so in the future people might prefer them as an intervention.
To make this a realistic choice, further research is needed to identify other nutrition-based interventions that benefit mental wellbeing, allowing different dietary interventions to be combined in future to provide greater results.
One potential option would be to combine Vitamin B6 supplements with talking therapies such as Cognitive Behavioural Therapy to boost their effect.
What do we already know about vitamin B6?
Vitamin B6 is a water-soluble vitamin that we must get through our food, as our bodies can’t make on their own. There are six different forms of B6, and pyridoxal 5’-phosphate (a.k.a PLP or P-5-P) is the most active form that the body can easily use for important functions.
B6 is like a busy, productive factory worker that operates in over 150 pathways in the body. Its two main roles include:
Building and breaking down molecules, including amino acids, fats, and neurotransmitters. Notably, it helps to break down the amino acid homocysteine. Too much homocysteine can be a risk factor for heart disease, stroke, and dementia.
Protecting us from the effects of stress. Over time, stressors like high blood sugar and inflammation can cause damage to our cells and tissues, leading to more serious conditions like diabetes.
In addition to its many tasks in the body, B6 is also busy at work in the brain.
Can I test my levels of B6?
If you are concerned that you may have low levels, blood tests are readily available. Serum or blood levels of P-5-P are the best indicator of long-term body stores of vitamin B6.
While the optimal healthy range for B6 has not been definitely determined, those who are at the lower end of the normal range may benefit from increasing B6 intake through diet or supplementation. Typically, those taking supplements have higher levels than the usual reference ranges. However, this does not necessarily indicate toxicity.
Reference
David T. Field, Rebekah O. Cracknell, Jessica R. Eastwood, Peter Scarfe, Claire M. Williams, Ying Zheng, Teresa Tavassoli. High?dose Vitamin B6 supplementation reduces anxiety and strengthens visual surround suppression. Human Psychopharmacology: Clinical and Experimental, 2022; DOI: 10.1002/hup.2852