- A water-soluble vitamin which consists of three compounds, pyridoxal, pyridoxol (also called pyridoxine) and pyridoxamine, each with a different function. They are found in low concentration in all animal and plant tissues especially fish, eggs and wholemeal flour. They are involved in protein, fat and carbohydrate metabolism and in brain function. Lack of the vitamin can cause lesions around the eyes, nose and mouth, peripheral neuritis and, in infants, convulsions. It is not recommended that supplements exceed 300 mg per day.