P5P50 (activated B-6)Item Description Predominant form of circulating vitamin B6 Pyridoxal 5' phosphate (P5P) is the active metabolite of pyridoxine and is the predominant form of plasma B6. P5P is required for proper absorption of B12 and magnesium, and for the production of gastric HCl. It is an important coenzyme in the metabolism of carbohydrates, fats, and proteins, and the elongation of essential fatty acids. It is required for the production of antibodies and red