What is peripheral neuropathy from vitamin B6?

Vitamin B6 (pyridoxine) toxicity can cause sensory peripheral neuropathy — tingling, burning, pain, or numbness in the hands and feet, sometimes spreading up the arms and legs. The risk accumulates with time and with cumulative intake across multiple products. A multivitamin, a B-complex, and a standalone B6 tablet taken together can push well past the 50 mg/day NHMRC tolerable upper limit without the person realising it. The TGA has received 250 adverse event reports of peripheral neuropathy linked to B6, with 152 assessed as most likely to be neuropathy.

What dose of B6 is considered safe?

The NHMRC tolerable upper intake level for B6 is 50 mg per day. The TGA currently requires mandatory warning labels on supplements providing more than 10 mg of B6 per day. A review of the tolerable upper limit is under way, with results expected early 2027. Many Australians exceed the upper limit simply by stacking common supplement combinations — multivitamin, B-complex, and a separate B6 tablet — without realising the total adds up.

What is changing in June 2027?

From June 2027, vitamin B6 supplements will become pharmacist-only medicines in Australia — meaning they will no longer be available from supermarkets or health retailers without pharmacist oversight. This is a meaningful structural change, but the researchers note it will not arrive quickly enough to prevent ongoing harm to people currently taking high-dose B6 products. In the meantime, a GP or pharmacist review of the full supplement list is the main protective mechanism.

B6 supplement warnings are failing Australians — new data shows why

What just happened

A new University of Sydney study published in the Internal Medicine Journal has done something uncomfortable: it has counted the problem.

Researchers analysed Australian pharmacy sales of vitamin B6 supplements across three years — 1 August 2022 to 31 July 2025, covering roughly 75% of the complementary medicine market. They found more than 20 million products sold containing daily doses exceeding 5 mg of B6, and more than 3 million products with daily doses above 50 mg — which is the NHMRC’s tolerable upper limit.

The TGA has been warning about vitamin B6 toxicity since 2020. In March 2023, it reduced the maximum allowable daily dose from 200 mg to 100 mg and introduced mandatory warning labelling on products providing more than 10 mg per day. The researchers’ finding: across the full three-year study period, sales “remained stable.” The regulatory interventions had no “discernible impact on purchasing patterns.”

The TGA has received 250 adverse event reports of peripheral neuropathy linked to vitamin B6, with 152 assessed as most likely to be neuropathy. These are not trivial outcomes — peripheral neuropathy from B6 toxicity can be persistent and, in some cases, irreversible.

Both-and

What makes B6 toxicity difficult to catch

Vitamin B6 toxicity is easy to underestimate because the harm is cumulative and diffuse. A person might take a multivitamin, a B-complex, and a standalone B6 tablet — each containing what looks like a modest dose — and together push well past the 50 mg/day upper limit without realising it.

Associate Professor Jennifer Hunter put it directly: “Even though the dose could be relatively low in each, if you’re taking multiple products you’ll quickly increase your dose.” The assessment is not a single bottle check; it is a totalling exercise across everything on the shelf.

The symptom profile adds another layer of difficulty. Tingling and numbness in the hands and feet — the early signs of peripheral neuropathy — are common in people over 40 for many reasons: early diabetes, carpal tunnel, cervical spine changes, B12 deficiency, thyroid dysfunction. B6 toxicity can sit hidden in this noise until it becomes severe.

The regulatory approach is losing

The study found a “marked decline” in products containing 200 mg or more of B6 — which looks like a win. But that decline was offset by more products in the 100–199 mg range. The market did not get smaller; it shifted.

This is what the researchers mean when they conclude that regulatory reform alone is “unlikely to adequately mitigate high-risk vitamin B6 use in Australia.” You can lower the ceiling; manufacturers can cluster just below it.

The structural fix — moving B6 supplements to pharmacist-only status — is not due until June 2027. Between now and then, the TGA’s primary mechanism is warning labels that the data shows are not changing consumer behaviour. Dr Mary Buchanan was blunt: “The TGA must take more meaningful and effective methods to educate the general population.”

Why this lands in general practice

The most actionable finding for GPs is that the supplement history matters more than ever — and that it needs to be specific. The question is not just “do you take any supplements?” It is: can you list everything you take, bring in your bottles, and let us add up the total B6 dose?

Associate Professor Hunter: “That might involve asking the patients to go home and carefully add up the total dose or bring in their bottles.”

For patients presenting with tingling or numbness in the peripheries, B6 toxicity should now be explicitly on the differential — alongside the more familiar candidates. The risk is not marginal; it is documented in 250 reports to the TGA, and it is sitting inside a pattern of purchasing behaviour the study shows has not changed in three years.

My two cents

What I notice in this data is the gap between regulatory intent and consumer behaviour — and how that gap persists even when the intent is well-designed. The TGA’s 2020 alert was appropriate. The 2023 mandatory labelling was appropriate. And yet: 20 million high-dose units sold in three years with no detectable signal of change.

The honest reading is that warning labels on supplement bottles are low-reach communication. They compete with packaging designed to project health and vitality, sold in environments that feel like wellness, purchased by people who are trying to look after themselves. The label that says “may cause nerve damage” is unlikely to win against the context that says “premium B-complex for energy and mood.”

What might actually work between now and June 2027? A GP asking at the next appointment. A pharmacist flagging the B6 stack at dispensing. A patient who hears this from a trusted clinical voice — rather than reading it in small print they are not looking for.

This is the pattern with a lot of supplement safety: the population-level signals are clear, but the individual clinical encounter is what changes behaviour. This data now gives us a specific reason to make that conversation happen at the next visit.

Verdict: yes — this research is directly actionable in general practice. If you or someone you know takes more than one supplement, it is worth totalling the daily B6 dose. If you are a GP managing a patient with unexplained peripheral symptoms, B6 intake belongs on the list.

Sources cited

‘Ongoing risk’ as vitamin B6 warnings fail to dent sales. RACGP newsGP, 4 August 2026. https://www1.racgp.org.au/newsgp/clinical/ongoing-risk-as-vitamin-b6-warnings-fail-to-dent-s