P₅P 50 is pyridoxal 5'-phosphate (P₅P), the active metabolite and predominant form of plasma pyridoxine (vitamin B₆). P₅P is beneficial to a number of physiological functions, providing a wide range of nutritional support as a coenzyme of over 140 enzymes. It is highly present in muscle, where it plays an important role in carbohydrate metabolism by aiding in the breakdown of glycogen into glucose. It is required for amino acid metabolism, including the conversions of methionine to cysteine and tryptophan to niacin. This B vitamin also helps to metabolize fats and is necessary for the elongation of essential fatty acids. P₅P is required for proper absorption and utilization of B₁₂ and magnesium, as well as for the production of gastric HCl. Vitamin B₆ also helps in tissue formation, red blood cell production, and is involved in maintaining the cellular balance of sodium and potassium.