Vitamin B6 / pyridoxine / P-5-P

Also known as pyridoxal 5 phosphate, p5p, vitamin b-6, pyridoxin.

Last reviewed October 9, 2026 · Jump to references

What is Vitamin B6 / pyridoxine / P-5-P?

In plain words

Vitamin B6 is a nutrient found in foods; pyridoxine and P-5-P are two forms of it. The body changes pyridoxine into an active form that helps process protein and make brain chemicals and hemoglobin, the oxygen-carrying protein in blood. Researchers study B6 in deficiency, nerve function, and brain health, but benefits from extra B6 in people who already get enough are not well established. Too much B6 from supplements can damage nerves.

Technical definition

Vitamin B6 is a water-soluble family of related compounds that includes pyridoxine and pyridoxal 5′-phosphate (PLP, or P-5-P), its principal active coenzyme form. The body converts pyridoxine to PLP, which binds to numerous enzymes and supports amino acid metabolism, neurotransmitter synthesis, and hemoglobin production rather than acting through a single receptor. Pyridoxine and P-5-P are marketed as dietary supplement ingredients in the United States; supplements are not FDA-approved for efficacy before marketing.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.