Vitamin B6, or Pyridoxine, is an essential nutrient, a group of six chemically similar compounds, vitamers. In its active form it is a coenzyme in over 140 reactions.

Plants synthesize pyridoxine forprotection from the ultraviolet-B radiation and to synthesize chlorophyll.  It can also be produced by intestinal bacteria.

Dietary deficiency of B6 is rare. For adult humans, daily recommendation is 1.0-2.0 mg.