An essential cofactor for amino acid neurotransmitter synthesis, immune antibody formation, and homocysteine clearance.
What it is
Vitamin B6 is an essential water-soluble B vitamin existing in six interconvertible vitamers: pyridoxine, pyridoxal, pyridoxamine, and their respective 5'-phosphate esters. In dietary supplements, it is formulated as pyridoxine hydrochloride (HCl) or the active coenzyme form, pyridoxal-5'-phosphate (P5P). P5P acts as an indispensable cofactor for over 140 enzymatic reactions, primarily governing transamination, decarboxylation, and racemization in human amino acid metabolism.
Also known as: Pyridoxal-5-Phosphate, P5P, Pyridoxine HCl, Vitamin B6
What it does
- Acts as a coenzyme in amino acid transamination and neurotransmitter synthesis (serotonin, GABA, dopamine).
- Supports hemoglobin synthesis and immune antibody production.
- Regulates plasma homocysteine levels via transsulfuration to cysteine.
- Helps alleviate PMS symptoms and morning sickness during pregnancy.
Amplified by probiotics
In the upper small intestine, pyridoxine is dephosphorylated and absorbed via passive carrier-mediated diffusion. In the colon, live probiotic bacteria—including Bifidobacterium longum and Lactobacillus reuteri—synthesize B6 vitamers de novo. Microencapsulated probiotic technology delivers active strains through gastric acid into the distal intestine, increasing local pyridoxal-5'-phosphate availability. Probiotic-derived B6 serves as an essential cofactor for bacterial amino acid decarboxylases, generating short-chain fatty acids and neuroactive amines (such as GABA). Furthermore, probiotics reduce intestinal mucosal inflammation, enhancing enterocyte alkaline phosphatase activity required for B6 dephosphorylation, intestinal uptake, and systemic utilization.
Typical dose
1.3–25 mg/day
The evidence
Evidence: strongComprehensive human clinical evidence validates vitamin B6 for reducing homocysteine, alleviating pregnancy-induced nausea, modulating PMS mood fluctuations, and supporting cellular immune response (Ueland et al. 2015, Biochimie; Wyatt et al. 1999, BMJ).
Safety & who should check first
Tolerable Upper Intake Limit is 100 mg/day for adults. Chronic long-term excessive intake (>200 mg/day) may cause sensory neuropathy. Safe in recommended doses during pregnancy.