What is Vitamin B6 Toxicity?

What is vitamin B6?

Vitamin B6 is a water-soluble vitamin and an essential nutrient for human function. It is needed for protein and carbohydrate metabolism, the formation of red blood cells, and certain brain cells. It also influences brain development, immune system health, and steroid hormone activity (1).

Vitamin B6 includes 6 compounds – pyridoxal, pyridoxine, pyridoxamine and their respective 5′ phosphates (2). The 5′-phosphate form of pyridoxal (PLP) is the active coenzyme form, and also the most common type of B6 found in human tissue. PLP levels are used to measure B6 blood levels in the body.

The recommended daily intake for adults is between 1.3 – 1.7mg (2). It is found in foods such as (1):

• Cereal grains
• Meat and poultry (particularly organ meats such as beef liver)
• Legumes
• Fish and shellfish
• Leafy green vegetables
• Nuts
• Fruits

Clinical deficiency is rare because most people get enough B6 from their diet. However, people who are more at risk of deficiency include those who drink excessive amounts of alcohol, women, the elderly, and people with thyroid disease (1).

Vitamin B6 in supplements

Vitamin B6 is commonly found in supplements such as multivitamins, migraine products, nerve health products, and energy drinks. Some of these are primarily B6 supplements, but many others include the vitamin as an additive. One example of this is magnesium supplements, which often include B6 because it is believed to help with magnesium absorption (although this is debated) (9,10). It may be labelled as pyridoxine, pyridoxal or pyridoxamine, depending on which form of the vitamin is included.

Most people do not need B6 supplements. As with other vitamins, it’s only necessary to take a supplement if you are deficient. Always speak to your doctor before starting any new supplements to ensure they are appropriate for you.

Understanding vitamin B6 toxicity

Vitamin B6 toxicity is associated with consuming high doses of B6 for an extended period of time. In some cases, lower doses can also cause toxicity over time. All reported cases have been linked to supplements – natural food-based sources of B6 will not cause toxicity (3,4).

Supplements containing vitamin B6 often greatly exceed the recommended daily intake, leading to a buildup of B6 in the body. The primary concern with B6 toxicity is its effect on the nervous system.

High levels of vitamin B6 can damage nerves, leading to a condition called peripheral neuropathy (3). Peripheral neuropathy happens when there is damage to the nerves located outside of the brain and spinal cord (peripheral nerves).

Symptoms & diagnosis

The main symptoms of vitamin B6 toxicity and peripheral neuropathy include (3):

• Numbness and tingling – frequently in the hands and feet, but may be present in other areas. Sometimes described as a ‘stocking-glove’ sensation.
• Difficulty walking or unsteady gait
• Pain or burning sensations
• Muscle weakness
• Loss of coordination

This list of symptoms is not exhaustive, and other less common symptoms may be present (e.g. nerve pain, cognitive changes, heart rate issues, muscle twitches and more). Further research and case studies are needed to confirm the prevalence of particular symptoms.

You should see a doctor if you experience any of these symptoms, especially if you are taking supplements containing vitamin B6. Keep in mind that vitamin B6 can be added to other supplements (such as magnesium) and is often listed by one of its chemical names – pyridoxine, pyridoxal, or pyridoxamine. It’s important to check the label of all vitamins and supplements that you’re taking.

Diagnosis of vitamin B6 toxicity typically involves a combination of:

• Medical history: The doctor will review the patient’s supplement intake, including the dose and duration of B6 supplementation.
• Physical examination: A neurological examination will assess sensory and motor functions.
• Blood tests: Blood tests can measure B6 levels, but these may not always correlate with the severity of symptoms (3).
• Electromyography (EMG): This test measures the electrical activity of muscles and nerves and can help confirm peripheral neuropathy.

All of these diagnostic methods can contribute towards diagnosis. However, a diagnosis can only be confirmed with a blood test.

Management of vitamin B6 toxicity

The primary treatment for vitamin B6 toxicity is to stop taking supplements containing B6. In most cases, symptoms gradually improve after supplementation is discontinued. However, recovery can be slow and may take several months or even years. In some cases, nerve damage may be permanent (3).

There is no specific antidote for vitamin B6 toxicity. However, other treatments may help manage symptoms:

• Pain medication: Over-the-counter or prescription pain relievers may help alleviate pain.
• Physical therapy: Physical therapy can help improve muscle strength and coordination.
• Occupational therapy: Occupational therapy can help patients adapt to any limitations caused by nerve damage.

Outlook

The prognosis for vitamin B6 toxicity varies depending on the severity of nerve damage and how quickly the condition is diagnosed and treated.

In most cases, symptoms improve after discontinuing B6 supplementation. However, some people may experience long-term or permanent nerve damage (3). At this point it’s unclear exactly how common it is to develop long-term damage. Further research and case reports will help doctors better understand recovery timelines.

Early diagnosis and prompt cessation of B6 supplementation are essential to minimise the risk of long-term complications.

Current research

In 2024, Dr Matthew Silsby was the recipient of Brain Foundation grant funding for the project “How B6 toxicity affects nerve function”. Dr Silsby’s research aims to determine the mechanisms by which B6 causes nerve damage, which could help to identify potential therapeutic targets.

Currently, researchers think the underlying mechanism could be that B6 disrupts the usual neurotransmitters responsible for preventing nerve overactivity. This nerve hyperexcitability could explain the types of sensory symptoms patients experience. 

Dr Silsby and his team will use neurophysiological testing to assess whether this theory about nerve hyperexcitability is correct. If confirmed, this could lead to better-targeted treatments aimed at stabilising overactive nerves, potentially improving symptom management while waiting for B6 to be eliminated naturally.

Read more about Dr Silsby’s research >

The impact of vitamin B6 toxicity: Dom’s story

“Not long after the birth of my first child, I began experiencing a myriad of frightening neurological symptoms – tingling, numbness, muscle twitching, coordination issues, neuralgia pain, extreme fatigue, and cognitive fog. My heart rate would spike unpredictably, and I struggled with light sensitivity and blood pressure fluctuations. It felt as though my body had suddenly broken down. After months of fear and countless medical appointments, I finally connected the dots: I was suffering from vitamin B6 toxicity.

What shocked me most was how little awareness there was in the medical community. My bloodwork showed B6 levels two times the level indicative of nerve damage, however, my GP at the time had never heard about B6 toxicity. I was offered little in the way of treatment, not from a lack of effort from my health care team, but a general lack of understanding of B6 toxicity and its system-wide effects. Instead, like many others, I was left to navigate this condition more or less on my own.

Eventually, I identified online support communities where others had experienced B6 toxicity. Through shared anecdotes, I began implementing a lower B6 diet, increasing hydration and electrolyte intake – simple interventions that generally seemed to help when no formal treatment was available. Although it is worth noting that there is no recovery silver bullet and any dietary changes should be trialled under the supervision of a doctor. Recovery just takes time, lots of it.

I share my story in the hope that greater awareness will lead to earlier diagnosis, better medical guidance, and ultimately, prevention for others unknowingly at risk from something as seemingly harmless as a vitamin.” – Dominic Noonan-O’Keefe, 33.

Recent news coverage

Throughout 2025, public awareness about vitamin B6 toxicity has increased significantly. In early January the issue was featured in The Guardian and on 7.30, the ABC’s current affairs program, with coverage continuing throughout the year.

This media attention has highlighted the stories of people living with vitamin B6 toxicity, and drawn attention to the risks of excess vitamin B6. You can access some of the key news stories & coverage below.

• Jan 5 – The Guardian – Simon never linked the pain in his hands and feet to multivitamins – but a pathology test did. Read more >
• Jan 8 – ABC – Warnings high doses of vitamin B6 over a long period could cause irreversible nerve damage. Read more >
• Jan 28 – ABC – Medical professionals fear cases of B6 toxicity are under-reported. Read more >
• May 19 – 9News – Nerve damage warning from excessive dosage of vitamin, says father. Watch now >
• Jun 28 – ABC – Australia’s TGA issues interim report to remove supplements high in B6 from shelves as toxicity cases rise. Read more >
• Jul 3 – ABC – TGA concedes it failed to prevent growing number of blood toxicity cases attributed to vitamin B6. Read more >
• Jul 3 – The Conversation – Too much vitamin B6 can be toxic. 3 symptoms to watch out for. Read more >
• Jul 20 – Sydney Morning Herald – Migraines, nerve damage: The Australians poisoned by over-the-counter vitamins. Read more >
• Nov 26 – ABC – TGA says some vitamin B6 to be removed, prescriptions needed after toxicity cases. Read more >

Supplement regulation in Australia

In Australia, all medicines and therapeutic goods are regulated by the Therapeutic Goods Administration (TGA), including vitamins and supplements. The table below explains the difference between types of TGA approval.

TGA Classifications (5,6)

Most products containing vitamin B6 are listed medicines. The TGA sets the maximum allowed dose and provides guidelines for labelling. As of June 2025, the daily dose restrictions are (7):

• 15 to 40 mg for children (dosage varies based on age).
• 100 mg for individuals aged 19 years and older.
• If the maximum recommended daily dose of the medicine provides more than 10 mg of pyridoxine, the following warning statement is required on the medicine label: “WARNING – Stop taking this medication if you experience tingling, burning or numbness and see your healthcare practitioner as soon as possible. [Contains vitamin B6].”

These restrictions were implemented in March 2023. Prior to that, the maximum adult dose was 200 mg, and warning labels were only displayed on products with doses 50 mg and above (8).

Updates on vitamin B6 regulation

Last updated: December 2, 2025.

Since the 2023 changes, there have continued to be concerns about the adequacy of these regulations and the potential for consumers to unknowingly ingest excessive amounts of vitamin B6.

In 2024, there was a proposed amendment to the Poisons Standard which recommended that all oral vitamin B6 supplements providing between 5 mg and 200 mg per day be rescheduled as Pharmacist Only (Schedule 3) medicines. This was rejected, and the TGA published an Interim Decision in June 2025 with an adjusted proposal.

They announced the outcome in late November 2025 and confirmed the following changes, which will come into effect in June 2027:

• Doses up to and including 50 mg/day to remain unscheduled;
• Doses greater than 50 mg and less than 200 mg/day to be classified as Schedule 3 (Pharmacist Only);
• Doses of 200 mg/day or more to be Schedule 4 (Prescription Only).

The rescheduling will affect about 100 products, requiring pharmacists to first speak with consumers before approving a purchase.

There are still some concerns about this change, particularly that it won’t come into effect until June 2027. Some stakeholders also think it doesn’t go far enough, and would like the original amendment to be reconsidered (changing all doses above 5mg to Schedule 3).

Overall, we welcome this stronger regulation as a critical step towards safeguarding Australians against the harmful effects of vitamin B6 toxicity, which can cause debilitating health problems.

Key takeaways

• Vitamin B6 toxicity is caused by taking excessive amounts of B6-containing supplements.
• This can cause peripheral neuropathy. The symptoms of peripheral neuropathy include numbness, tingling, pain, and weakness in the hands and feet.
• Symptoms usually improve after stopping B6 supplementation, but nerve damage may be permanent in some cases.
• Always check the label of supplements for vitamin B6 content, which is often listed as pyridoxine, pyridoxal, or pyridoxamine.
• Talk to your doctor or pharmacist before taking any vitamin B6 supplements.
• Do not take supplements unless they are needed.

Further information & resources

Learn more about vitamin B6 toxicity and related topics:

• How are vitamins regulated in Australia? – blog post from the Therapeutic Goods Administration.
• How B6 toxicity affects nerve function – information about Dr Matthew Silsby’s 2024 Brain Foundation Research grant.
• Peripheral neuropathy – Brain Foundation overview article.
• B6 Toxicity Australia – a Facebook page founded by Dominic, whose story is featured in this article.
  • Other support groups can also be found on Facebook. Please always be cautious of your safety in online communities, and never take advice from an online group without speaking to your doctor first.
• News articles and patient stories – linked under subheading ‘Recent news coverage’.

References:

1. Better Health Channel VIC, 2024, Vitamin B. https://www.betterhealth.vic.gov.au/health/healthyliving/vitamin-b 
2. Eat For Health, 2006, Vitamin B6 – Nutrient Reference Values for Australia and New Zealand. https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/vitamin-b6 
3. A Hemminger & B Wills, 2023, Vitamin B6 Toxicity. https://www.ncbi.nlm.nih.gov/books/NBK554500/ 
4. P Stover & M Field, 2015, Vitamin B-6. DOI: 10.3945/an.113.005207
5. TGA, 2025, Listed Medicines. https://www.tga.gov.au/products/medicines/non-prescription-medicines/listed-medicines 
6. TGA, 2025, Registered Medicines. https://www.tga.gov.au/products/medicines/registered-medicines 
7. Department of Health, Disability and Ageing, 2025, Therapeutic Goods (Permissible Ingredients) Determination (No. 2) 2025. https://www.legislation.gov.au/F2025L00683/asmade/text/5
8. TGA, 2022, Health supplements containing vitamin B6 can cause peripheral neuropathy. https://www.tga.gov.au/news/safety-alerts/health-supplements-containing-vitamin-b6-can-cause-peripheral-neuropathy
9. L Noah et al, 2020, Effect of vitamin B6 supplementation, in combination with magnesium, on severe stress and magnesium status: secondary analysis from an RCT. DOI: 10.1017/S0029665120004395
10. E Pouteau et al, 2018, Superiority of magnesium and vitamin B6 over magnesium alone on severe stress in healthy adults with low magnesemia: A randomized, single-blind clinical trial. DOI: 10.1371/journal.pone.0208454