Vitamin B6 P5P Liquid

Each drop of this vitamin B6 liquid provides 848 mcg of vitamin B6 as pyridoxal 5-phosphate, which is 61% of the nutrient reference value. Take 1 drop per day in water with food, as the label directs; two drops give 1.7 mg. One drop is one serving, and a 100ml bottle holds 1333 servings. The liquid contains purified water, pyridoxal 5-phosphate and potassium carbonate, and comes in 100ml and 250ml.

Sources: NIH Office of Dietary Supplements; product label.

P5P is the short name for pyridoxal 5-phosphate, the active form of vitamin B6, the form that enzymes in the body use directly. Vitamin B6 is a family name for six related compounds: pyridoxine, pyridoxal and pyridoxamine, and the phosphate forms of each. Pyridoxal 5-phosphate is the coenzyme for more than 100 enzyme reactions, most of them to do with protein, and doctors measure vitamin B6 status by the level of it in the blood, which is why the name appears on test results. The vitamin dissolves in water, so the body does not store it and needs a supply every day.

Sources: NIH Office of Dietary Supplements; Food Standards Scotland; MeSH, US National Library of Medicine.

P5P drops give vitamin B6 already in its active form. Pyridoxine, the form in most supplements and fortified foods, is converted into pyridoxal 5-phosphate in the liver first. Absorption from supplements is similar across the forms, and the gut strips the phosphate from P5P before absorption and puts it back inside the body, so the case for P5P rests on form and safety rather than absorption. In a 2017 laboratory study on human nerve cells, pyridoxine harmed the cells and blocked the enzymes that depend on pyridoxal 5-phosphate, while P5P did not; that finding comes from cells in a dish and has not been tested in people. This liquid is a P5P supplement only, with no pyridoxine hydrochloride.

Sources: NIH Office of Dietary Supplements; peer-reviewed study (Vrolijk and colleagues, Toxicology in Vitro, 2017).

P5P supplies vitamin B6, which the body uses in the handling of protein and carbohydrate from food. It also builds haemoglobin, which carries oxygen in the blood, and makes the nerve-signalling chemicals serotonin and noradrenaline. Vitamin B6 also keeps blood levels of homocysteine, an amino acid, in the normal range, and it helps the body produce lymphocytes for the immune system. Research on supplements above normal intakes is mixed: a review of nine trials in about a thousand women found vitamin B6 eased premenstrual symptoms more than placebo, but most of the trials were small and weak, and trials in 6837 heart patients found 40 mg a day lowered homocysteine without reducing heart attacks.

Sources: NIH Office of Dietary Supplements; Food Standards Scotland.

Adults need about 1.4 mg of vitamin B6 a day for men and 1.2 mg for women, and food alone provides that for most people. Vitamin B6 is one of the vitamins where more is not better: UK advice is not to take more than 10 mg a day from supplements unless a doctor advises it, and the European upper level set in 2023 is 12 mg a day. One drop at 848 mcg sits well inside both, and a liquid lets the amount rise one drop at a time rather than in capsule-sized jumps. Anyone told by a practitioner to take a higher fixed amount can use the P5P capsules, which give 34 mg a capsule for the period advised.

Sources: Food Standards Scotland; NIH Office of Dietary Supplements; EFSA.

P5P drops are for people who want an active B6 supplement, vitamin B6 in the form enzymes use, at a small amount they can adjust. That includes people on a restrictive diet, people on a prescription that lowers vitamin B6, and people with a tested low level, each with their GP's agreement, and anyone who prefers a liquid they can add to water. Food alone meets the requirement for most people, so anyone unsure whether they need extra vitamin B6 should ask a GP for a blood test rather than self-treating.

Sources: Food Standards Scotland; NIH Office of Dietary Supplements.

P5P is most often taken with magnesium or with the other B vitamins, and both pairings have been studied. In a trial of 264 stressed adults, 300 mg of magnesium with 30 mg of vitamin B6 for eight weeks worked no better than magnesium alone overall. Vitamin B6 taken with folic acid and vitamin B12 lowers homocysteine more than any one of them alone. Prescription drugs are the interactions that matter: some antiepileptic drugs, including valproate, carbamazepine and phenytoin, lower blood levels of vitamin B6, and high-dose pyridoxine lowers blood levels of phenytoin and phenobarbital in return. Anyone on regular prescriptions should ask a pharmacist first.

Sources: NIH Office of Dietary Supplements; peer-reviewed trial (Pouteau and colleagues, PLOS ONE, 2018).

P5P at the amounts in food and low-dose supplements has no reported side effects. The risk with vitamin B6 comes from high doses over long periods: more than 200 mg a day, or lower amounts for a long time, can damage the sensory nerves and cause loss of feeling, tingling or pain in the hands and feet. Symptoms usually fade once the supplement is stopped, but in some people who took large amounts for months they did not reverse. New tingling or numbness means stop and speak to a GP. Anyone pregnant or breastfeeding, or taking prescribed tablets, should speak to a GP or pharmacist first.

Sources: NIH Office of Dietary Supplements; Food Standards Scotland.