Many US dietary supplement companies also market a B 6-only dietary supplement with 100mg per daily serving. PLP also plays a cofactor role in releasing selenium from selenohomocysteine to produce hydrogen selenide, which can then be used to incorporate selenium into selenoproteins.

PLP is required for the conversion of tryptophan to niacin, so low vitamin B 6 status impairs this conversion. Vitamin B6, also known as pyridoxine, is a water-soluble vitamin that your body needs for several functions. To function as a transaminase coenzyme, PLP bound to a lysine of the enzyme then binds to a free amino acid via formation of a Schiff's base.Its active form, pyridoxal 5′-phosphate, serves as a coenzyme in more than 140 enzyme reactions in amino acid, glucose, and lipid metabolism.

In 2010, the European Food Safety Authority (EFSA) published a review of proposed health claims for vitamin B 6, disallowing claims for bone, teeth, hair skin and nails, and allowing claims that the vitamin provided for normal homocysteine metabolism, normal energy-yielding metabolism, normal psychological function, reduced tiredness and fatigue, and provided for normal cysteine synthesis. Animals cannot synthesize any of the various forms of the vitamin, and hence must obtain it via diet, either of plants, or of other animals.The process then dissociates the amine group from the amino acid, releasing a keto acid, then transfers the amine group to a different keto acid to create a new amino acid. As for safety, Tolerable upper intake levels (ULs) for vitamins and minerals are identified when evidence is sufficient. If you’re interested in taking B6 for morning sickness, speak with your doctor before starting any supplements.

PLP aids in the synthesis of hemoglobin, by serving as a coenzyme for the enzyme aminolevulinic acid synthase.

Another small study found that 50 mg of vitamin B6 along with 200 mg of magnesium per day significantly reduced PMS symptoms, including mood swings, irritability and anxiety, over the course of one menstrual cycle ( 24). Studies have linked high blood levels of circulating homocysteine with an increased risk of AMD ( 40, 41).