Vitamin B6 (Pyridoxine)

Vitamin B6 is the umbrella term for several related forms (pyridoxine, pyridoxal, and pyridoxamine) that the body converts to the active coenzyme PLP. PLP is involved in over a hundred enzyme reactions, particularly those that process amino acids. It is also needed to make haemoglobin, and to convert tryptophan to niacin (which is why vitamin B6 status interacts with niacin requirements).

Most UK adults meet the requirement from food without thinking about it. The reason B6 has a prominent safety section, despite low deficiency rates, is the well-documented peripheral neuropathy risk from supplements at moderately high doses over months to years.

Values per 100g from USDA SR Legacy and McCance and Widdowson 7th edition; the site's food entries currently store macros only.

UK Reference Nutrient Intake (RNI) for vitamin B6 is set by SACN (1991).

Vitamin B6 deficiency is uncommon in healthy UK adults. When it occurs, signs include:

• Cracked lips, sore tongue, mouth ulcers
• Skin rashes (seborrhoeic dermatitis-like changes)
• Confusion, irritability, low mood
• Microcytic anaemia (small red blood cells)
• Weakened immune response
• In severe long-running deficiency: seizures

At higher risk in the UK

• People with kidney disease, particularly on dialysis.
• People with autoimmune conditions (rheumatoid arthritis, coeliac disease, Crohn's, ulcerative colitis).
• People on certain medications: isoniazid (TB), penicillamine, hydralazine, levodopa-carbidopa.
• Heavy alcohol use.
• People with severely restricted diets.

NHS supplement guidance, restated for emphasis: do not take more than 10mg of vitamin B6 a day in supplements unless advised to by a doctor.

This is one of the strictest UK supplement uppers, and is set this low specifically because of the well-documented peripheral neuropathy risk:

• Peripheral neuropathy: nerve damage in the hands and feet, presenting as numbness, tingling, pins and needles, burning sensations, and weakness. NHS guidance is that taking 200mg or more of vitamin B6 a day can lead to a loss of feeling in the arms and legs known as peripheral neuropathy. The effect of doses between 10mg and 200mg is unclear, so there is not enough evidence on how long those doses are safe to take.
• Symptoms usually improve when the supplement is stopped, but recovery is not always complete; in some long-running cases the damage is permanent.

The risk is from supplements, not from food. The amount of B6 in even the most generous food serving is well below the threshold for nerve damage.

If you take a B-complex or multivitamin, check the label: most reputable UK products contain 1 to 5mg of B6, well within the safe range. Stacked products (a multivitamin plus a separate B-complex plus a "stress formula" plus an energy drink, for example) can push total daily B6 well above 10mg without notice. Add up the products you take.

If you have unexplained numbness, tingling, or pins and needles in the hands or feet and you take supplements: review your B6 intake with a GP or pharmacist. Stop high-dose B6 products and seek advice.

Routine vitamin B6 supplementation is not needed for healthy UK adults. The food supply covers the requirement.

Practical guidance:

• Stay at or below 10mg per day of B6 from supplements unless a doctor has advised more.
• Read the label on B-complex, multivitamin, and "stress" supplements; the B6 content is often listed in milligrams.
• If you are taking more than one supplement, add the B6 amounts together. Stacking is the most common way doses creep up.
• Higher-dose B6 has historically been promoted for premenstrual symptoms; the NHS position is that the evidence is weak and the 10mg-per-day upper applies.

Supplementation at therapeutic doses is sometimes used for specific medical conditions (some metabolic disorders, certain neuropathies, hyperemesis gravidarum) under specialist supervision; that is not general supplement advice.

• The B-complex pair: Folate and Vitamin B12 work alongside B6 in homocysteine metabolism.
• Other B vitamins: Vitamin B1, Vitamin B2, Vitamin B3, Vitamin B5, Vitamin B7 (Biotin).
• Best food sources: Salmon, Chicken, Beef, Banana, Potato, Chickpeas.

• NHS. Vitamins and minerals: Vitamins B. nhs.uk/conditions/vitamins-and-minerals/vitamin-b. Adult RNI, food sources, and the 10mg supplement upper.
• SACN. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Department of Health Report 41 (1991).
• Public Health England. McCance and Widdowson's The Composition of Foods, 7th summary edition (2015).

This page is reference information for UK shoppers. It is not medical advice. Unexplained nerve symptoms while taking B6-containing supplements should be discussed with a GP or pharmacist.