B vitamins play an important role in different cellular processes that are essential for the nervous system and brain function, including several that help to maintain an appropriate balance between neural inhibition and excitation. It does this by upregulating inhibition and downregulating excitation.
This role is important because when the equilibrium shifts towards excitation it has been implicated in different neuropsychiatric disorders, including anxiety and depression.
It has been proposed that high doses of B vitamins might be an effective strategy for enhancing behaviourally observable effects of neural inhibition and damping excessive excitation.
In a study published in the journal Human Psychopharmacology: Clinical and Experimental, researchers investigated the effects of vitamin B6 or B12 supplementation for 1 month in different behavioral outcome measures.
Vitamin B6: Reduction in Anxiety and Depression Symptoms
For the study, the team included a total of 478 adults that had self-reported anxiety and depression. They were evaluated at baseline and after supplementation. The study was conducted over the course of 5 years by successive cohorts.
Participants received either a lactose placebo tablet, Vitamin B6 tablets, or Vitamin B12 tablets. The B12 tablets each contained 1000 μg of B12 as methylcobalamin, and the B6 tablets each contained 100 mg of B6 as pyridoxine hydrochloride.
The participants were screened using the Screen For Anxiety Related Disorders (SCAARED) and Mood and Feelings Questionnaire (MFQ).
In the end, the researchers found that vitamin B6 can be helpful in reducing anxiety and depression symptoms. The participants in the treatment group taking B6 had a significant reduction in their SCAARED and MFQ tests compared to the other participants.
The effect of the high dose of vitamin B6 supplementation is obtained by an increased inhibitory GABAergic effect.
This is an important finding because vitamin B6 supplements can be obtained over-the-counter and may be helpful for some patients with anxiety and depression, without the side effects of prolonged use of different anti-anxiety and depression drugs.
David T. Field, et al. High-dose Vitamin B6 supplementation reduces anxiety and strengthens visual surround suppression. 2022. Hum Psychopharmacol Clin Exp. https://doi.org/10.1002/hup.2852