Vitamin B₆ is used by the body as a catalyst in reactions that involve amino acids. Vitamin B₆ deficiency is rare, since most foods eaten contain the vitamin.

Vitamin B₆ is a water-soluble vitamin. The recommended dietary allowance (RDA) for vitamin B₆ is 2.0 mg/day for the adult man and 1.6 mg/day for the adult woman. Vitamin B₆ in the diet generally occurs as a form called pyridoxal phosphate. In this form, it cannot be absorbed by the body. During the process of digestion, the phosphate group is removed, and pyridoxal is produced. However, the body readily absorbs pyridoxal, and converts it back to the active form of the vitamin (pyridoxal phosphate).

Poultry, fish, liver, and eggs are good sources of vitamin B₆, comprising about 3-4 mg vitamin/kg food; meat and milk contain lesser amounts of the vitamin. The vitamin also occurs, at...