Vitamins (B₁, B₆, B₁₂)

Abstract Vitamin B complex, particularly thiamine (B₁), pyridoxine (B₆), and cobalamin (B₁₂), play essential roles in neuro-metabolic regulation and mood stability. Acting as coenzymes in neurotransmitter synthesis, mitochondrial energy production, one-carbon metabolism, and myelin maintenance, these vitamins support both cognitive and emotional health. Deficiencies in B₆ and B₁₂ are linked to impaired serotonin, dopamine, and GABA synthesis, elevated homocysteine levels, and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to depression, anxiety, and sleep disturbances. Clinical evidence demonstrates that B-vitamin supplementation reduces cortisol levels, improves memory performance, and alleviates emotional fatigue in high-stress populations. Furthermore, synergistic combinations of B vitamins with 5-HTP, magnesium glycinate, L-Theanine, and Ashwagandha amplify effects on serotonin production, GABAergic modulation, stress buffering, and neuroprotection. This review summarizes the mechanistic pathways, clinical research evidence, and target populations for B-vitamin-based nutritional strategies, highlighting their role as foundational cofactors in mood regulation and stress resilience