Vitamin B-6 is required for the metabolism of lipids, carbohydrates, and proteins. It facilitates the conversion of amino acids from one to another and is necessary for the normal synthesis of hemoglobin and the normal function and growth of red blood cells. It is also needed for the synthesis of the neurotransmitters serotonin, gamma amino butyric acid (GABA) and dopamine and for the conversion of essential fatty acids into prostaglandins.