P-5-P Pyridoxal Phosphate, P5P, is a coenzyme form that provides immediate transport of B-6 to active cell sites and does not require the normal conversion in the liver. Vitamin B6 is the master vitamin for processing amino acids?the building blocks of all proteins and some hormones. Vitamin B6 helps to make and take apart many amino acids and is also needed to make the hormones, serotonin, melatonin, and dopamine.