Vitamin B6: Forms, Food Sources, Deficiency and Excess
Vitamin B6 (pyridoxine): what it does, food sources, intake levels, why upper limits differ between the US, Canada, EU and UK, and the nerve damage linked to high-dose supplements.
Content last updated . This page has not been medically reviewed.
What is Vitamin B6 good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Using energy from protein and carbohydrates
Established roleVitamin B6 helps the body use and store energy from the protein and carbohydrates in food.
Supplements: Helping use energy from food is not the same as adding energy. We found no good evidence that extra B6 raises energy in people who are not deficient.
Normal nerve function
Established roleVitamin B6 helps nerves work normally. Deficiency can cause nerve problems in the hands and feet.
Supplements: Supplements are not shown to add benefit when intake is already adequate; they correct deficiency. Very high doses can themselves damage nerves.
Making haemoglobin
Established roleVitamin B6 helps make haemoglobin, the part of red blood cells that carries oxygen.
Supplements: Supplements correct a deficiency-related anaemia; no good evidence of extra benefit when intake is adequate.
Making brain chemical messengers
Established roleThe active form of B6 takes part in making most neurotransmitters, the chemical messengers between nerve cells, including GABA.
Supplements: Two small studies on memory at high doses found no clear benefit; we found no evidence that supplements improve mood or thinking in people who are not deficient.
Breaking down and using protein
Established roleVitamin B6 helps the body break down proteins. The more protein you eat, the more B6 you need.
Supplements: Supplements are not shown to add benefit when intake is already adequate; they correct deficiency.
Making antibodies
Established roleVitamin B6 helps the body make antibodies, part of the immune defence.
Supplements: This describes a normal role. We did not find evidence that extra B6 boosts immunity in people who are not deficient.
Keeping blood sugar in normal ranges
Established roleVitamin B6 helps keep blood sugar in normal ranges as part of normal metabolism.
Supplements: A normal role, not proof that supplements treat or prevent blood sugar problems. We did not review treatment evidence.
Helper (cofactor) for many enzymes
Established roleThe active form of B6, called PLP, helps many enzymes in the body work, including in one-carbon metabolism.
Supplements: Your body makes PLP from dietary B6; supplements do not improve this when intake is adequate.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (2)
- Blood Sugar BalanceEstablished role
B6 helps keep blood sugar in normal ranges as part of normal metabolism; supplement benefit for blood sugar was not reviewed.
- Immune SupportEstablished role
B6 helps make antibodies as part of normal immune function. No good evidence that supplements add protection in people who are not deficient.
Body systems (4)
- Nervous SystemDocumented risk
High-dose B6 supplements can cause nerve damage in the arms and legs; the effect often improves after stopping but can be permanent.
- Metabolism & WeightEstablished role
B6 helps the body use and store energy from protein and carbohydrates. We found no evidence that supplements help with weight.
- Blood Sugar SupportEstablished role
B6 helps keep blood sugar in normal ranges as part of normal metabolism. This does not show that supplements treat blood sugar problems.
- Immune SystemEstablished role
B6 helps make antibodies. This is a normal role; there is no good evidence that extra B6 boosts immunity when intake is adequate.
Body parts (2)
- Nervous SystemDocumented risk
Very high intakes of B6 can damage peripheral nerves.
- Immune SystemEstablished role
B6 helps make antibodies. Extra B6 is not shown to boost immunity when intake is adequate.
Functional actions (1)
- Nervous System SupportEstablished role
B6 helps maintain normal nerve function and the making of neurotransmitters. Supplements matter mainly when intake is low.
Root causes (1)
- Nutrient DeficiencyDeficiency link
B6 deficiency is uncommon in the US but can occur with kidney failure, liver disease or heavy alcohol use, and can cause anaemia, nerve problems, confusion and mouth sores.
Habits (1)
- Balanced NutritionEstablished role
Most people can get enough B6 from a varied diet (pork, poultry, fish, peanuts, bananas, oats, fortified cereals); gut bacteria also make some.
Biomarkers (1)
- HemoglobinEstablished role
B6 helps make haemoglobin, and deficiency is linked to a form of anaemia. Haemoglobin is affected by many other causes.
Conditions & symptoms (6)
- Vitamin B 6 DeficiencyDeficiency link
Not enough B6 causes a deficiency. It is uncommon in the US and more likely with kidney failure, liver disease or heavy alcohol use.
- AnemiaDeficiency link
MedlinePlus says deficiency can cause a form of anemia, in line with B6's role in haemoglobin.
- Peripheral NeuropathyDeficiency link
MedlinePlus lists peripheral neuropathy among deficiency effects. The same symptoms can come from B6 excess, so a clinician should assess them.
- ConfusionDeficiency link
Confusion is listed as a deficiency symptom. It has many other causes and this does not show supplements help.
- Mental DepressionDeficiency link
Depression is listed as a deficiency symptom. It has many other causes and this does not show supplements treat depression.
- StomatitisDeficiency link
Mouth and tongue sores are listed as deficiency symptoms. They have many other causes.
Documented risks and interactions (1)
- Risk of nerve damage at high supplement doses. Long-term high doses of B6 can cause numbness or loss of feeling in the arms and legs. This usually improves after stopping, but can sometimes be permanent.
Overview
Vitamin B6, also called pyridoxine, helps the body use and store energy from protein and carbohydrates and helps form haemoglobin, the part of red blood cells that carries oxygen, according to the NHS. [1] MedlinePlus adds that it helps make antibodies, maintain normal nerve function and keep blood sugar in normal ranges, and that the more protein you eat, the more B6 you need. [2] Its alternative names include pyridoxal and pyridoxamine. [2]Numbness or tingling in the hands or feet, or trouble coordinating movement, in someone taking B6 supplements, needs a conversation with a clinician soon. Large doses of B6 can cause these effects, and the NHS says they usually improve after stopping the supplements, though in a few cases the effect can be permanent. [2][1]
Food sources
The NHS lists pork, poultry, some fish, peanuts, soya beans, wheatgerm, oats, bananas, milk and some fortified breakfast cereals, and says bacteria in the bowel can also make some B6. [1] MedlinePlus lists tuna and salmon, banana, legumes, beef and pork, nuts, poultry, whole grains, chickpeas, and fortified breads and cereals. [2] See foods high in biotin, thiamin, riboflavin, niacin, B6 and pantothenic acid.Official intake levels
Published levels for the groups named, not personal advice. Upper limits differ a lot between bodies, which is why you should never treat one country's figure as universal. See vitamin intake references compared.| Body, country and year | Group | Level for vitamin B6 |
|---|---|---|
| NHS, UK, page reviewed 2020 | Adults 19 to 64, men / women | About 1.4 mg / 1.2 mg a day [1] |
| US Dietary Reference Intakes, as listed by MedlinePlus (review 2025) | Adults 19 to 50 / males over 50 / females over 50 | RDA 1.3 mg / 1.7 mg / 1.5 mg a day; 1.9 mg in pregnancy and 2.0 mg in lactation [2] |
| Health Canada, table dated 2025 | Adults 19 to 30 | RDA 1.3 mg a day; upper level 100 mg a day [3] |
| EFSA, EU, opinion adopted 2023 | Adults, including pregnancy and lactation | Upper level 12 mg a day (earlier EU limit set in 2000: 25 mg a day) [4][5] |
| NHS, UK, 2020 | Supplement guidance | Do not take more than 10 mg a day in supplements unless a doctor advises it [1] |
| Daily Value on US labels (FDA, 2024) | Label reference only | 1.7 mg [6] |
The EFSA panel based its figure on peripheral neuropathy, which it described as the well-established critical effect of excess B6, and said EU populations are unlikely to exceed it except regular users of high-dose B6 food supplements. [4]
Deficiency
Established. MedlinePlus says B6 deficiency is uncommon in the United States and can occur in people with kidney failure, liver disease or excessive alcohol use. It can cause confusion, depression, irritability, mouth and tongue sores, a form of anemia and peripheral neuropathy. [2] These symptoms overlap with many conditions and with B6 excess, so a clinician should assess them before anyone treats themselves. See vitamin deficiency symptoms.Too much B6
The NHS says taking 200 mg or more a day can lead to peripheral neuropathy, a loss of feeling in the arms and legs, and that the effect of doses between 10 mg and 200 mg is unclear. [1] A 2025 case-based review described three people who developed neuropathic symptoms after taking too much B6 from different sources, and whose symptoms improved after they stopped; three cases cannot show how common this is. [7] A Dutch case-control study of 381 people with a chronic nerve condition found that more patients than controls used B6 supplements (31% against 22%), yet blood B6 levels, daily dose and duration did not differ significantly, and the authors judged a link unlikely. [8] The evidence is therefore mixed on lower doses and clear on very high ones. Full detail is on vitamin B6 toxicity and upper limits.Many B-complex, energy and multivitamin products also contain B6, so amounts add up; check every label. See B-complex products.
What research shows for specific uses
| Question | What the source found | Label |
|---|---|---|
| Roles in red blood cells, nerves and protein use | The NHS and MedlinePlus describe these roles, and MedlinePlus links deficiency to anemia and nerve problems. [1][2] | Established nutritional role |
| Nausea in pregnancy and premenstrual symptoms | Not reviewed here; see vitamin B6 for nausea in pregnancy and PMS. | See that page |
| Energy, mood or sleep in people who are not deficient | Proper evidence not found. We read the NHS and MedlinePlus pages and searched PubMed for B6 supplement reviews; the results concerned toxicity, not benefit. | Marketing claim |
Testing
Proper evidence not found in the pages we read for a routine B6 blood test or its interpretation. Do not diagnose from symptoms; see deficiency testing and its limits.Related
All vitamins · Understanding vitamins · Vitamin B12Frequently asked questions
What foods are high in vitamin B6?
Pork, poultry, fish, peanuts, bananas, oats, fortified cereals and legumes. [1][2]
How much B6 is too much?
It depends on the body: the EU limit is 12 mg a day, Health Canada's is 100 mg, and UK advice is 10 mg or less in supplements unless a doctor says otherwise. [4][3][1]
What are the signs of too much B6?
Loss of feeling in the arms and legs (peripheral neuropathy), numbness and trouble coordinating movement. [1][2]
Is B6 deficiency common?
MedlinePlus says it is uncommon in the United States. [2]
Does B6 help with energy?
Proper evidence not found in the sources we searched; the vitamin helps use energy from food but that is not the same as adding energy.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: established nutritional role / deficiency treatment, evidence of harm, mixed, insufficient evidence and marketing claim. "Proper evidence not found" means we searched the sources named and found nothing usable.
Safety and precautions
- Medicines: Proper evidence not found in the pages we could read (NIH Office of Dietary Supplements pages were blocked). See medication interactions and ask a pharmacist.
- Pregnancy and breastfeeding: the US RDA rises to 1.9 mg and 2.0 mg. [2] Do not add B6 supplements without asking your midwife, doctor or pharmacist.
- Children: upper levels are lower (Health Canada: 30 mg a day for ages 1 to 3; EFSA scales its figure down). [3][4] Keep supplements out of reach of children; see vitamin overdose in children.
- Kidney and liver conditions, alcohol: these raise deficiency risk. [2] A 2023 review says kidney disease changes water-soluble vitamin needs and supplementation should be managed by the care team. [9] See vitamins and kidney or liver disease.
- Before surgery: Proper evidence not found specific to B6; see vitamins before surgery.
- Quality: see quality testing and certifications.
References
- NHS (UK). B vitamins and folic acid. Page last reviewed 3 August 2020. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia (US National Library of Medicine). Vitamin B6. Review date 1/21/2025. Read 2026-10-23.
- Health Canada. Dietary reference intakes tables: Reference values for vitamins. Page dated 2025-11-19. Read 2026-10-23 through a web-fetch tool, which returned the tables as a text summary; direct download was blocked.
- EFSA Panel on Nutrition, Novel Foods and Food Allergens. Scientific opinion on the tolerable upper intake level for vitamin B6. EFSA Journal 2023;21(5):e08006. Read 2026-10-23.
- European Food Safety Authority. Overview on Tolerable Upper Intake Levels as derived by the Scientific Committee on Food (SCF) and the EFSA NDA Panel, version 1, August 2025. Read 2026-10-23 (text extracted from the PDF; table layout reconstructed).
- US Food and Drug Administration. Daily Value on the Nutrition and Supplement Facts Labels. Content current as of 03/05/2024. Read 2026-10-23.
- Kościńska-Shukla I, Jaskólska M, Grochowalska K, et al. Underestimated pyridoxine consumption and neurotoxicity: a case-based review. Rheumatol Int 2025;45(6):144. Read 2026-10-23.
- Visser NA, Notermans NC, Degen LA, et al. Chronic idiopathic axonal polyneuropathy and vitamin B6: a controlled population-based study. J Peripher Nerv Syst 2014;19(2):136-44. Read 2026-10-23.
- Kędzierska-Kapuza K, Szczuko U, Stolińska H, et al. Demand for water-soluble vitamins in a group of patients with CKD versus interventions and supplementation: a systematic review. Nutrients 2023;15(4):860. Read 2026-10-23.