Key Findings
- High-dose vitamin B6 (100 mg daily) significantly reduced self-reported anxiety in young adults over one month.
- The calming effect may be due to enhanced GABA activity and increased visual inhibition in the brain.
- No significant mental health benefits were seen with vitamin B12 supplementation in this study.
Vitamin B
Vitamins are a crucial part of a healthy diet. Every vitamin plays a distinct role in the human body. For instance, while vitamin A is necessary for vision, without vitamin K, you would have bleeding problems. Among the vitamins (A, B, C, D, E, and K), vitamin B is by far the one with the most members. As a result, it is often referred to as vitamin B complex. Vitamins B6 and B12 are two of its members, and both play a role in ensuring that the activities that happen in your nervous system work optimally. Simply put, they help your brain function well.
A recent study by David T. Field and his colleagues at the School of Psychology and Clinical Language Sciences, University of Reading, Reading, UK, has found that individuals taking daily vitamin B6 supplements reported lower anxiety and depression levels compared to those who were not on this vitamin supplement. The study, which was published in Human Psychopharmacology: Clinical and Experimental, suggests that this association may be linked with the reduced neuronal overexcitability observed in participants who took this vitamin supplement.
How Was This Study Conducted?
The researchers aimed to assess the effects of a one-month supplementation with either vitamin B6 or B12 in high doses on a range of behavioural outcome measures that have to do with neural excitation and inhibition. To do this, they recruited a total of 478 young adults. At the start of the study, self-reported anxiety and depression levels were recorded.
The participants were then randomly grouped to receive either a placebo, vitamin B6 or B12 tablet. Lactose-intolerant people were excluded from the study because the placebo contained lactose. Furthermore, participants who were taking multivitamins that contained vitamin B or were taking drugs that affected the rate of vitamin B absorption were excluded. To prevent bias that may arise during the experiment, this study was double-blinded. This means that neither the participants nor the researchers knew the groups the participants belonged to. Participants in the vitamin B6 group were given 100 mg of pyridoxine hydrochloride daily for 30 to 35 days, a dose significantly higher than the recommended daily intake of 1.3 mg for adults, but within the tolerable upper intake level. The B12 group received 1000 μg of methylcobalamin daily. Supplements and placebos were identical in appearance and administered in a double-blind fashion, ensuring neither participants nor researchers knew which group anyone belonged to.
Measures Used To Measure Brain Activity
The researchers used a few sensory measures to measure inhibitory function. Some of these measures included:
Surround depression of visual contrast detection: This refers to the ability of the brain to filter out unnecessary information when one looks at an object. Normally, when we look at an object, the brain blocks out the surrounding visual stimuli to help us focus on that specific object.
Tactile reaction time: This refers to how fast a person responds to a touch stimulus.
Important Finding: Vitamin B6 And Mental Health
Comparing the vitamin B6 vs the placebo groups, the researchers observed that the participants who took vitamin B6 reported lower levels of anxiety and depression than those on placebo.
Although a similar finding was observed in the vitamin B12 group for self-reported anxiety levels, the study’s findings indicated that this was not significant.
Notably, the sample size for anxiety outcomes included 88 participants in the B6 group, 90 in the B12 group, and 87 in the placebo group, enhancing the reliability of comparisons. The anxiety reduction observed in the B6 group was statistically significant (p < 0.001), with a medium effect size (Cohen’s d = 0.37). The same effect was not observed in depression scores, which only showed a non-significant trend toward improvement.
Potential Mechanism: Increased GABAergic Actions
The researchers theorised that this finding may be associated with the increased GABAergic actions in the brain.
It is important to note that GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter in the brain. This implies that when GABA is released, it reduces excitation of the brain, thereby producing a calming effect in the individual. This is observed in the fact that many of the drugs used to treat anxiety actually act through GABA.
Moreover, from the study findings, the researchers observed an increased surround depression of visual contrast detection among participants on vitamin B6 supplements. This also suggests that vitamin B6 supplementation may be linked with the inhibition of some neural pathways in the brain. The authors drew parallels between this effect and previous findings with GABA-enhancing medications, suggesting that B6’s role in converting glutamate to GABA may be the central mechanism. Interestingly, this GABA-related inhibitory response was specifically evident in the visual contrast test with surround masking—a psychophysical test linked to GABAergic activity in the brain. The supplement did not significantly affect other inhibitory measures, such as binocular rivalry or tactile sensitivity, likely due to limited statistical power for those tests.
Limitations
While the findings are promising, the authors acknowledged a few limitations. Commenting on the study’s limitations, the authors highlighted that the study had a “limited statistical power.” This implies that there was a high chance of missing subtle effects in the outcome measures that were considered in the study. Furthermore, the short duration of the study may not be sufficient to assess the long-term mental health effects of vitamin B6.
Related Reading:
Medical University of Vienna: Vitamin B1 May Help Prevent Alcohol-Related Dementia
Vitamin D Deficiency Could Increase the Risk of Dementia
FAQs
What Dose Was Used in the Study?
Participants received 100 mg of vitamin B6 (pyridoxine hydrochloride) daily for about one month. This dose is far above the recommended 1.3 mg/day for adults but below the 100 mg/day upper intake level considered safe. Always consult a doctor before using high-dose supplements.
What is the FDA’s stance on B6 supplementation as a treatment for depression or anxiety?
The FDA has not yet approved vitamin B6 as a treatment for depression or anxiety. The research finding in this article only points to the fact that research suggests it may have potential benefits in both conditions, particularly when taken in high doses.
Are there any possible side effects of vitamin B6?
Yes, particularly when taken in high doses, vitamin B6 intake can cause nerve damage, numbness, and other side effects. It is important to note that a dose below 100 mg is considered safe. Hence, it is important to consult your doctor before taking high doses.
What other lifestyle changes can support mental health?
Other lifestyle changes that have been found to be beneficial in maintaining good mental health include regular exercise, eating a balanced diet, maintaining good hygiene, and easing off stress.
Final Thoughts
The study’s findings suggest that vitamin B6 supplementation may have potential benefits for anxiety and depression. Since supplementation is a simple lifestyle modification, it could offer a convenient approach to managing both conditions. However, despite the potential benefits, vitamin B6 supplementation should not be seen as a standalone treatment for mental health conditions. Moreover, high doses may have risks (nerve damage, numbness, peripheral neuropathy), hence, it is important to seek a healthcare provider’s advice before using it.
References
Field, D. T., Cracknell, R. O., Eastwood, J. R., Scarfe, P., Williams, C. M., Zheng, Y., & Tavassoli, T. (2022). High‐dose Vitamin B6 supplementation reduces anxiety and strengthens visual surround suppression. Human Psychopharmacology: Clinical and Experimental, 37(6). https://doi.org/10.1002/hup.2852
