Summary: B vitamins play an essential role in the function of the nervous system, including helping to down-regulate neuronal excitation. This paper combined results of double-blind placebo-controlled trials that assessed the individual impacts of Vitamin B12 and B6 supplementation on anxiety. The researchers then measured these supplements in relation to visual processing and cognition. The participants were randomised to control groups receiving either Vitamin B12, B6 or placebo. The researchers evaluated whether supplementation could alter neural excitation and inhibition by measuring with a range of behavioural outcomes. Self-reported anxiety and depression were measured after supplementation and also at baseline before taking supplementation. Vitamin B6 supplementation showed to reduce self-reported anxiety and was also trending towards reduced depression. It also showed impactful in other areas of neuronal excitability, but did not reliably influence all outcome measures. Vitamin B12 supplementation also influenced trends towards changes in anxiety and visual processing.
Abstract:
Objective: Vitamins B6 and B12 are involved in metabolic processes that decrease neural excitation and increase inhibition. This double-blind study investigated the effects of supplementation for 1 month with a high-dose of B6 or B12, compared to placebo, on a range of behavioural outcome measures connected to the balance between neural inhibition and excitation.
Methods: 478 young adults were recruited over five linked phases. Self-reported anxiety (N = 265) and depression (N = 146) were assessed at baseline and after supplementation. Several sensory measures acted as assays of inhibitory function and were assessed post-supplementation only; these were surround suppression of visual contrast detection (N = 307), binocular rivalry reversal rate (N = 172), and a battery of tactile sensitivity tests (N = 180).
Results: Vitamin B6 supplementation reduced self-reported anxiety and induced a trend towards reduced depression, as well as increased surround suppression of visual contrast detection, but did not reliably influence the other outcome measures. Vitamin B12 supplementation produced trends towards changes in anxiety and visual processing.
Conclusions: Our results suggest that high-dose Vitamin B6 supplementation increases inhibitory GABAergic neural influences, which is consistent with its known role in the synthesis of GABA.
Article Publication Date: 19.07.22
DOI: 10.1002/hup.2852
