Vitamin SupplementVitamin B-6 is an essential nutrient required for the metabolism of lipids, carbohydrates, and proteins. It facilitates the conversion of amino acids from one to another as needed, and is necessary for normal synthesis of hemoglobin, as well as for the normal function and growth of red blood cells. It is also needed for the synthesis of neurotransmitters and for converting essential fatty acids into prostaglandins (chemical messengers).