Vitamin B6 toxicity: how much is too much, and what it does to nerves

What vitamin B6 is, and how much you need

Vitamin B6 is a family of six related compounds, including pyridoxine, pyridoxal and pyridoxamine. Supplements most often use pyridoxine hydrochloride. The body’s working form is pyridoxal 5′-phosphate (PLP), which more than 100 enzyme reactions depend on.

Adults need 1.3 mg a day up to age 50, then 1.7 mg for men and 1.5 mg for women, with 1.9 mg in pregnancy and 2.0 mg while breastfeeding. High intakes from food have not been reported to cause harm. The problem is supplements.

Too little B6 is uncommon on its own and usually comes with low levels of other B vitamins. Whether any supplement helps neuropathy is covered in our supplements guide.

Where the extra B6 comes from

About 28 to 36 percent of people in the US take a supplement containing B6. The risk grows when several products each add some:

• Multivitamins. Most contain B6.
• B-complex and B6-only products.
• Magnesium, zinc and iron supplements, some of which add B6.
• “Anti-stress” and “nerve support” formulas, and B6 taken for premenstrual symptoms.
• Fortified foods and drinks, such as some breakfast cereals and energy drinks.

How to read the label. Find the vitamin B6 line on the Supplement Facts panel. Count every form, whether pyridoxine hydrochloride or pyridoxal 5′-phosphate (P-5-P). Check the mg per serving and how many servings a day the label suggests. The Daily Value (DV) for B6 is 1.7 mg, so every 100% DV is 1.7 mg.

Labels vary widely. In the NIH Dietary Supplement Label Database, one product sold for sciatic nerve support lists 30 mg per serving (1,765% DV). Another nerve formula lists 16.67 mg per capsule, three a day: about 50 mg a day. Add up every product, fortified food and drink included.

Symptoms of too much B6

B6 toxicity mainly injures sensory nerves, the ones that carry touch, vibration and the sense of where your limbs are. Typical symptoms:

• Numbness, tingling or burning in both feet, later in both hands, which can also feel clumsy.
• Unsteady walking. Losing position sense, the sense of where your feet are without looking, makes balance depend on your eyes. This is called sensory ataxia.
• Oversensitive skin or aching limbs in some people.
• Effects beyond the nerves at high doses: painful skin lesions, sensitivity to sunlight, nausea and heartburn.

None of this is specific to B6. Diabetes, low vitamin B12, an underactive thyroid and some medicines can cause the same pattern, so the usual causes still need checking. The blood tests that find the common causes.

How much is too much: the official limits

Official bodies agree that too much B6 damages nerves. They disagree about where the line is.

Why they differ. Mostly the starting point. The US panel took studies in which people averaged 200 mg a day for up to five years without detected nerve damage, and halved that dose. EFSA started from 50 mg a day, a reference point taken from a case–control study, and divided by four, partly because lower doses seem to take longer to cause symptoms. Australia’s 2026 draft builds on EFSA’s work.

Rules for products. Since 1 March 2022, Australia’s Therapeutic Goods Administration (TGA) has required a warning on medicines, including supplements, with more than 10 mg of B6 a day. Under a November 2025 decision, from 1 June 2027 products with more than 50 mg and up to 200 mg a day will be pharmacist-only, while those above 200 mg remain prescription-only. In 2026, Health Canada reported a possible link between nerve damage and natural health products, such as supplements, taken at 10 mg of B6 a day or more, and asked for label warnings on them. The same review did not find enough evidence of a link with prescription B6 medicines. In the US, a 2021 citizen petition asking for a warning label, and prescription-only status for doses over 10 mg, had no FDA decision at the agency’s 2022 interim reply, and we found no later ruling.

What the evidence shows at different doses

Grams a day: clear harm. The classic 1983 report described seven adults who took 2 to 6 grams (2,000 to 6,000 mg) a day for 2 to 40 months. They developed progressive sensory ataxia, with deep loss of position and vibration sense, and slowly improved after stopping. In a 1992 study, five healthy volunteers given 1 or 3 grams a day all developed sensory symptoms, sooner on the higher dose.

Below 500 mg a day: disputed. Several case reports describe neuropathy at these doses, while the long-term studies behind the US limit, averaging 200 mg a day, found none. In a 1987 study at a clinic treating premenstrual tension, 103 of 172 women with raised B6 levels reported nerve symptoms, at an average of 117 mg a day for 2.9 years. By November 2024, the Dutch pharmacovigilance center, Lareb, had received 238 reports of nerve damage with B6 products, 79 involving a product with a daily dose of 12 mg or less. Australia’s TGA, with 250 reports of peripheral neuropathy by 31 October 2025, says the risk cannot be excluded below 50 mg a day.

Reports like these can’t prove that B6 caused each case, and many people take several products at once. Still, they have moved regulators toward lower limits, and they fit the finding that sensitivity to B6 varies between people.

How B6 toxicity is diagnosed

What to do, and how recovery goes

Stop the extra B6. If tingling, burning or numbness starts while you take a supplement with B6, stop it and see your doctor as soon as possible. The NIH notes that symptoms usually stop if the supplement is stopped as soon as they appear. Don’t switch to another product with B6.

Prescribed B6 is different. B6 is part of a doxylamine–pyridoxine medicine for nausea and vomiting in pregnancy, and is prescribed with isoniazid, a tuberculosis drug, to prevent nerve damage. The US limit doesn’t apply to B6 given as treatment under a physician’s care. If you get tingling, burning or numbness while taking B6 that a clinician prescribed or recommended, including a prenatal vitamin, don’t stop it on your own; call that clinician promptly.

Protect your feet meanwhile. Numb skin can’t warn you about a blister or a burn. Check your feet every day, don’t walk barefoot or in socks alone, even indoors, and keep heating pads and hot water bottles off your feet. The two-minute daily foot check. If your balance is off, try our balance exercises. How nerves recover in general.

When to get help urgently

• Go to an emergency department, or call 911, for weakness in the legs or arms, often with tingling or numbness, that is getting worse over hours or days, especially if it started in the feet and is spreading upward, or for any trouble breathing or swallowing. These can be signs of Guillain-Barré syndrome, which needs hospital care.
• Call 911 for sudden numbness or weakness in the face, an arm or a leg, especially on one side of the body, sudden trouble speaking, or sudden loss of balance. These can be signs of a stroke.
• Call your doctor today if your walking or balance is getting worse from one day to the next, or if you have fallen.
• Be seen the same day or the next if a blister, cut or burn on a numb foot turns red, warm, swollen or painful, or if you have a fever. Get any wound on a numb foot checked promptly, and call your doctor if it has not started to heal within a few days.
• See your doctor as soon as you can for new tingling, burning or numbness while taking a B6 supplement. Stop the supplement first. If the B6 was prescribed, call the prescriber instead of stopping it.

Common questions

Related reading

Supplements for neuropathy and the B6 problem · Can neuropathy be reversed? · Numbness in hands and feet · Nerve conduction study and EMG · The daily foot check · Foods to avoid with neuropathy