New University of Sydney research has found that Australians are still purchasing vitamin B6 supplements in potentially harmful quantities, years after public health warnings began.
The Australian-first study quantified vitamin B6 purchases in Australian pharmacies to identify patterns of potentially high-risk use.
From 2023 to 2025, the researchers found that 20.32 million products with a maximum recommended daily dose of vitamin B6 exceeding 5 mg were purchased through 15.8 million transactions. Around one in five pharmacy transactions involved products with a combined daily dose of more than 50 mg.
‘In fact, more than 3 million purchases involved vitamin B6-containing products with a combined total dose exceeding the new Therapeutic Goods Administration (TGA) threshold intended to minimise harm,’ said senior author Associate Professor Joanna Harnett.
Why warnings aren’t cutting through
The TGA has been progressively tightening its approach to vitamin B6 over several years. Since 2022, medicines containing daily doses of vitamin B6 above 10 mg have been required to carry a warning statement which was previously only required for daily doses above 50 mg. The maximum permitted daily dose in listed medicines was also reduced from 200 mg to 100 mg, with lower limits for children.
Despite these measures, the problem has persisted – with the majority of the 174 incidents recorded in the TGA’s adverse event database reported since 1 January 2023.
Part of the problem is the persistent belief that complementary medicines are safe.
‘Collectively, there appears to be an ongoing perception that because something is natural, it is safe,’ A/Prof Harnett said.
Then there is the wide range of products containing vitamin B6.
‘Vitamin B6 is currently included in a range of supplements marketed for energy, mood, immunity and hormonal health,’ A/Prof Harnett said.
Because it’s available over-the-counter without professional advice, it’s not always obvious to consumers that these products might contain high doses of vitamin B6.
‘In conjunction with that, these formulations, whether they’re multimineral and vitamin formulations, often have so many ingredients that it’s hard to find unless you’re reading the label specifically to look for that ingredient,’ she said.
‘[Products] also often have vitamin B6 in brackets, and it’s listed as pyridoxine hydrochloride, which to most people is difficult to understand.’
There are also behavioural patterns when it comes to products like complementary medicines that can be hard to shake.
‘We do know from other research colleagues at the RMIT that people generally don’t read labels – which is probably the single biggest determinant,’ A/Prof Harnett said.
New regulations are coming
From 1 June 2027, oral preparations containing more than 50 mg of vitamin B6 but not more than 200 mg per recommended daily dose will be rescheduled as Pharmacist Only medicines. Products containing 200 mg or higher will remain Schedule 4, while those containing 50 mg or less will continue to be available for general retail sale.
The transition will require pharmacies to move certain products behind the counter, with manufacturers already preparing for the change.
But A/Prof Harnett said this is only part of the picture.
‘To effectively reduce the risk of vitamin B6-related adverse effects, stronger consumer and health practitioner education about the potential harms associated with excessive intake is needed alongside regulatory changes to reduce ongoing high-risk exposure.’
The implementation window before the 2027 changes take effect was a key motivation behind the research. ‘We still have [almost] a full year, and our data would suggest that we continue to have exposure to higher doses that are much higher doses than recommended daily intakes.’
One of the most significant findings from the research is that consumers can exceed the 50 mg threshold by combining lower-dose products – a risk that’s not captured by the upcoming scheduling changes. The study also identified high-risk purchasing behaviours, including buying multiple vitamin B6-containing products in a single transaction and repeat purchases consistent with prolonged use or stockpiling.
‘While the next stage of regulatory reform to be enforced from next year is certainly welcome, it may not be sufficient on its own,’ A/Prof Harnett said. ‘The implementation period for scheduling extends the potential for stockpiling, meaning that higher-risk exposure will persist without strengthened risk communication and practitioner education.’
When to be concerned
Chronic intake of high doses of vitamin B6 have been found to cause nerve damage, leading to symptoms like numbness, tingling, pain and other neurological effects.
‘This is often under-recognised by both consumers and health professionals, showing many are unaware of the risks associated with prolonged or high dose vitamin B6 intake,’ A/Prof Harnett said.
The symptoms of vitamin B6 toxicity and deficiency overlap – with both potentially producing neuropathic symptoms.
‘Any sensory symptoms such as pins and needles in the hands and feet, unusual pain in the hands and feet, balance issues, or any new symptom that develops following higher dose or prolonged use of vitamin B6 should prompt a referral to a GP for assessment,’ she said.
‘Neuropathy can have multiple causes, including poorly controlled diabetes, so a GP assessment is important to rule out those causes – including vitamin B6 toxicity.’
What pharmacists should be doing now
In A/Prof Harnett’s view, pharmacists shouldn’t wait for the 2027 regulatory deadline to act.
At dispensing events, asking about supplements should become routine. ‘It’s part of good history taking to ask: what other medicines are you taking, including complementary medicines, which refers to herbs and vitamin and mineral supplements,’ A/Prof Harnett said.
For patients managing multiple supplements for specific indications, the conversation should extend beyond B6. ‘Discerning whether or not that’s appropriate for that person, how many they’re taking, and whether or not there could be a cumulative dose of anything, including vitamin B6, is an important consideration,’ she said.
Home Medicines Reviews (HMRs) could also be appropriate.
‘Pharmacists should consider supplementation or complementary medicines more broadly in HMRs – and not just ask people whether they take them, but perhaps be mindful of what’s in the [medicines] being taken,’ A/Prof Harnett said.
For pharmacists, the takeaway is clear. ‘Pharmacists should be prepared to ask people questions about their supplement use, be mindful of whether the products contain vitamin B6, and whether doses greater than 50 mg are being consumed through multiple product intake – identifying excessive doses where possible.’
