Vitamin B6is the term for three related compounds, pyridoxine, pyridoxal and pyridoxamine and their phosphorylated derivatives which are pyridoxine 5'-phosphate, pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate. Vitamin B6technically refers to all six of these vitamers, although vitamin B6is used interchangeably with pyridoxine.

Pyridoxine, pyridoxine 5'-phosphate, and pyridoxine glucosides are found in plant foods. Glycosylated pyridoxine forms of vitamin B6range from 5 to 75% of the total vitamin B6content in fruits, vegetables, and grains.

The other vitamers, primarily pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate, are found in animal products. There is very little or none of the glycosylated pyridoxine form of vitamin B6in animal products.

Vitamin B6is soluble in water and stable to heat and acid. However, oxidation and exposure to alkaline conditions or UV light destroys vitamin B6.

Pyridoxal 5'-phosphate is involved in more than 100 biochemical reactions as a coenzyme. These reactions include the metabolism of glycogen and amino acids, the synthesis of nucleic acids, and the synthesis and metabolism of hemoglobin.

Pyridoxal 5'-phosphate is also involved as a coenzyme in the synthesis of sphingomyelin and other sphingolipids and the neurotransmitters serotonin, dopamine, norepinephrine, histamine, and gamma-aminobutyric acid