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Vitamin B6 is having a moment, and not the good kind. Australia’s medicines regulator is tightening the rules on B6 supplements after hundreds of reports of nerve damage. Europe has slashed its safe upper limit. And many people who take B6 have no idea how much they’re actually getting.
I’m a big fan of vitamin B6. It’s one of the most important nutrients for mood, nerves, hormones, and energy, and I wrote a whole guide to 13 science-backed vitamin B6 (P5P) benefits. But B6 is also a perfect example of a truth I share with clients all the time: the dose makes the poison.
Here’s what the newest research and regulations say about B6 toxicity, why the form of B6 you take matters, and how to use it safely.
- Too much B6 can damage nerves, causing tingling, burning, or numbness, usually in the hands and feet.
- Problems can start lower than we thought. Australia found nerve damage below 50 mg a day. Europe’s upper limit is now 12 mg a day.
- Pyridoxine is the main suspect. Lab research shows high levels of this inactive form can block active B6 (P5P).
- Hidden B6 adds up fast across multivitamins, magnesium blends, energy drinks, and sleep or PMS formulas.
- Too little and too much B6 both cause tingling, so test, don’t guess.
What Are the Symptoms of Too Much Vitamin B6?
Vitamin B6 toxicity shows up as peripheral neuropathy, which means damage to the nerves outside your brain and spinal cord. The sensory nerves that carry feeling from your skin are hit hardest.
Watch for:
- Tingling or “pins and needles,” usually starting in the feet or hands
- Burning or electric-type nerve pain
- Numbness or reduced feeling
- Muscle weakness
- Clumsiness or trouble with balance, especially in the dark
These symptoms can sneak up slowly. Many people blame them on aging, poor circulation, or blood sugar, and never connect them to the supplements in their cabinet.
Why Vitamin B6 Toxicity Is Suddenly in the News
For decades, B6 toxicity was considered rare. The classic studies tied it to very high B6 doses around 1,000 mg/day, with a few cases at 500 mg/day over many months. Recent reporting from Australia has changed that picture.
- Australia’s TGA received 239 adverse event reports for B6 products in the first half of 2025 alone, more than in all of 2024.
- By the end of October 2025, the TGA had counted 250 reports of neuropathy tied to vitamin B6 products. In about 150 of them, high B6 levels were also reported.
- The TGA’s review found that 103 people reported severe and sometimes permanent harm from B6, including nerve damage and muscle weakness that affected their daily lives and jobs.
- New Zealand’s Medsafe has also issued an alert on vitamin B6 and peripheral neuropathy, urging clinicians to ask about supplements in anyone with nerve symptoms.
The TGA’s conclusion was that many people simply don’t know B6 can cause nerve damage. That’s exactly why I wanted to write this post.
Is Vitamin B6 Really the Cause? Correlation vs. Causation
I’ll be honest: when I first saw the headlines, my scientist brain asked a question few articles do. Are some of these cases really caused by B6, or are sick people simply more likely to be taking supplements? The answer depends on the dose.
At high doses, B6 clearly causes nerve damage. The evidence here is strong:
- In the early 1980s, otherwise healthy people taking megadoses of pyridoxine developed sensory neuropathy. They had no other illness to explain it.
- Symptoms usually improve after people stop B6, one of the better signs of true cause and effect.
- Higher doses bring more risk, animal studies reproduce the damage, and lab research offers a clear mechanism: the “B6 paradox” I explain below.
- People born with a faulty version of the enzyme that pyridoxine blocks develop the same kind of sensory neuropathy.
At low doses, the picture is much murkier. Most of the recent numbers come from voluntary adverse event reports. These are valuable early warnings, but they can’t prove that B6 caused any one person’s symptoms. Here’s why:
- Reverse causation: Many people start B6 because they already have tingling or nerve pain. It’s a classic remedy for carpal tunnel and neuropathy. If their symptoms continue, B6 can look guilty when it was the treatment, not the cause.
- Sick people take more supplements: Diabetes, chemotherapy, low B12, thyroid problems, and alcohol can all damage nerves. Reports rarely rule these out.
- Headlines drive reports: Australia’s 2025 spike in reports came during intense media coverage and a class action. Attention alone increases reporting.
- A high blood level isn’t proof: About 150 of the 250 Australian reports mentioned elevated B6. But anyone taking a supplement will test high, especially soon after a dose. That shows exposure, not harm.
- The low limits are built on caution: When EFSA set its 12 mg limit, it noted that it couldn’t identify a lowest harmful dose from human data. It applied safety factors to limited evidence, including a dog study.
B6 toxicity at high doses is real and well proven. At modest doses, some reports are probably coincidence, but regulators can’t rule out genuine cases in sensitive people, so they’ve chosen caution. I think that’s reasonable. It’s also exactly why I’d rather test your blood level than guess, and why I favor P5P over pyridoxine.
How Much Vitamin B6 Is Too Much?
It depends on where you live, because experts don’t agree. Here’s how the limits compare for adults:
| Region | Adult limit or rule |
|---|---|
| United States | Upper limit of 100 mg per day |
| Europe (EFSA) | Upper limit cut to 12 mg per day in EFSA’s 2023 review, including during pregnancy and breastfeeding |
| Australia (now) | Products over 10 mg/day must carry a nerve-damage warning |
| Australia (June 2027) | Up to 50 mg: general retail. 50–200 mg: pharmacist only. Over 200 mg: prescription only. |
One of the most important findings from Australia: nerve damage can happen below 50 mg a day, especially when people take several B6-containing products at the same time. There’s no single magic number that’s safe for everyone. In the Netherlands, for example, 79 of 238 B6 nerve-pain reports involved 12 mg a day or less, according to the TGA’s review.
The Vitamin B6 Paradox: How Too Much Can Leave You Short
Here’s the part that fascinates me. Taking too much of the wrong form of B6 may actually leave your nerves starved of active B6.
In a cell study testing every form of B6, researchers found that pyridoxine, not P5P, damaged nerve cells in the lab. Pyridoxine also blocked two enzymes that depend on P5P. The authors called this “the vitamin B6 paradox”: a flood of the inactive form competes with the active form your body actually uses.
A later review dug into the mechanism. It concluded that blocking the enzyme that activates B6 is the likeliest cause of pyridoxine nerve damage. That enzyme, pyridoxal kinase, is needed to make P5P. When it’s jammed, GABA signaling in sensory nerves may suffer. GABA is your calming neurotransmitter, and sensory nerves without enough of it may become overexcited and damaged.
Is P5P Safer Than Pyridoxine?
Based on this research, I believe P5P is much more effective and likely safer than pyridoxine, and it’s the form I prefer. Here’s how they compare:
| P5P (Pyridoxal-5-Phosphate) | Pyridoxine HCl | |
|---|---|---|
| Form | Active, ready to use | Inactive; must be converted |
| Blocks B6 enzymes at high levels? | Not in lab studies | Yes, in lab studies |
| Nerve damage in lab studies | Not seen | Seen, dose-dependent |
| How regulators treat it | Same as all B6 | Same as all B6 |
| Found in | Higher-quality supplements | Most multivitamins, energy drinks, cheaper products |
The TGA hasn’t published a breakdown of its reports by B6 form, and its rules treat all forms the same. But the case at the center of Australia’s B6 controversy, a proposed class action over Blackmores Super Magnesium+, involves a product made with pyridoxine hydrochloride at about 60 mg per daily dose, roughly 29 times the recommended intake and fully legal at the time. The lawyers say they’re seeing similar complaints about B-complex, magnesium, and zinc products. Those everyday mass-market products typically use pyridoxine, the cheap, common form, rather than P5P.
But I want to be honest about the limits. Most of this evidence comes from cell studies, not people. Australia’s regulator counts P5P as vitamin B6 in its safety rules, and I’ve seen online reviews of people reporting toxic-feeling symptoms after 50 mg of P5P taken alone, without other nutrients. P5P is the smarter form, not a free pass for mega-doses.
Hidden Sources of Vitamin B6
Most people with B6 toxicity didn’t set out to take a lot of B6. They took several products that each contained some. B6 is added to more products than you’d guess:
- Multivitamins and prenatal vitamins
- B-complex and “energy” formulas
- Magnesium blends (magnesium + B6 is a popular combination)
- Energy drinks and some sports drinks
- Sleep, stress, and mood supplements
- PMS, hormone, and morning sickness products
- Fortified breakfast cereals and bars
Vitamin B6 can hide under several names: pyridoxine, pyridoxine hydrochloride, pyridoxal 5-phosphate (P5P), pyridoxal 5-phosphate monohydrate, pyridoxal, or pyridoxamine. Line up every bottle you take, find these names, and add the milligrams together. Many of my clients are surprised by the total.
This is one reason I’m picky about supplements in general. See my guides to the best natural vitamin brands and the synthetic vitamins I avoid to protect the gut.
Who Is Most at Risk of B6 Toxicity?
- People “stacking” supplements: a multi, a magnesium blend, an energy drink, and a sleep formula can add up quickly.
- People taking high-dose B6 on its own for PMS, nausea, carpal tunnel, or mood, especially for months at a time.
- People who already have neuropathy, such as from diabetes or chemotherapy, because B6 symptoms can blend in with existing nerve problems.
- Pregnant women taking B6 for morning sickness on top of a prenatal. Check your total with your OB or midwife.
Too Little vs. Too Much: Both Cause Tingling
Here’s what makes B6 tricky. Low B6 can cause nerve pain and tingling too, which is why B6 is used for carpal tunnel and nerve pain. Even Australia’s regulator noted that deficiency can also be associated with neuropathy.
So if you have tingling, the answer isn’t to automatically add more B6, or to automatically stop it. The answer is a blood test. Plasma PLP is the best single marker of your B6 status, and it can show whether you’re running low or high.
You can order functional lab panels through my Fullscript-powered Labs page, or work with me to interpret your results and build a plan that fits your body.
Explore Functional Lab Testing Work With MeWhat to Do If You Think You’re Getting Too Much B6
- Stop taking all B6-containing supplements and talk with your healthcare provider.
- Gather every bottle and add up your total daily B6, including multis, magnesium blends, drinks, and formulas.
- Ask for a plasma PLP (vitamin B6) blood test. Ideally, test before your symptoms have had a long time to fade, since levels drop after you stop.
- Tell your doctor about your symptoms and supplements. Many clinicians still don’t think of B6, so bring it up.
- Be patient. Many people improve after stopping, but recovery can take months, and some reported cases involved lasting nerve damage.
New numbness, weakness, or balance problems always deserve a medical evaluation. B6 is one possible cause among many.
How I Use Vitamin B6 Safely in My Practice
None of this means you should fear B6. Low B6 is common and causes real problems, from low mood to anemia. The goal is the right amount, in the right form, for the right person. Here’s my approach:
- Food first. Meat, fish, poultry, and potatoes deliver well-absorbed B6 with no known toxicity risk from food alone.
- Choose P5P over pyridoxine, inside a balanced B-complex rather than high-dose B6 on its own.
- Keep long-term doses modest unless a practitioner is monitoring you.
- Count every source on every label.
- Test, don’t guess, especially before and during higher-dose use.
- Stop and test if tingling, numbness, or burning appears.
B vitamins work best as a team. B6 needs riboflavin to be activated, and it works alongside folate and B12. For more, see why B12 deficiency guidelines may be set too low and the MTHFR supplements that changed my life. You’ll find my favorite moderate-dose P5P B-complex in my vitamin B6 supplement recommendations.
Frequently Asked Questions About Vitamin B6 Toxicity
Tingling, burning, or numbness, usually starting in the hands and feet, are the most common symptoms of vitamin B6 toxicity. Some people also notice muscle weakness, clumsiness, or trouble with balance. Because low B6 can cause similar nerve symptoms, a plasma PLP blood test is the best way to tell which problem you have.
It can be for some people. Australia’s regulator found that nerve damage can happen below 50 mg a day, especially when people take several B6 products at once, and Europe’s upper limit is just 12 mg a day. The U.S. upper limit is 100 mg. If you take 50 mg or more long term, do it with a practitioner who can check your blood level.
Lab research suggests that pyridoxine, not P5P, is the main driver of B6 nerve toxicity, because high levels of pyridoxine compete with active P5P and block P5P-dependent enzymes. That’s a key reason I prefer P5P. Still, regulators treat all forms of B6 the same, so P5P isn’t a license for mega-doses.
At high doses, yes. Healthy people taking megadoses have developed neuropathy that improved after stopping, and the mechanism is well understood. At lower doses, the evidence is weaker, because many reports involve people who already had nerve symptoms or other health conditions. Regulators treat low-dose reports as a warning sign rather than proof.
Toxicity from food alone isn’t a known problem. Reported cases come from supplements, often from taking several products that each contain B6. Whole foods like meat, fish, poultry, and potatoes are a safe way to meet your needs.
Many people improve after stopping all B6 supplements, but recovery can take months, and some cases reported to Australia’s TGA involved lasting nerve damage. The sooner you stop and get tested, the better your odds.
Multivitamins, B-complexes, magnesium blends, energy drinks, and sleep, stress, mood, PMS, and pregnancy formulas often contain B6. Check labels for pyridoxine, pyridoxine hydrochloride, pyridoxal 5-phosphate, or pyridoxamine, and add up the total from every product you take.
The Bottom Line on Vitamin B6 Toxicity
Vitamin B6 is essential, and plenty of people run low. But the newest data show that nerve damage from B6 supplements is more common, and happens at lower doses, than we once believed. The likeliest culprit is high-dose pyridoxine, which can crowd out the active P5P your nerves depend on.
Get B6 from food first. If you supplement, choose P5P inside a B-complex, keep the dose modest, add up every label, and test rather than guess. For the full picture on what this vitamin does for you, read my guide to vitamin B6 (P5P) benefits and deficiency signs. And if stress and sleep are part of your story, my book Cortisol Fix walks you through the whole picture. #TheHealthyRD
The information on this website has not been evaluated by the Food & Drug Administration or any other medical body and is shared for educational purposes only. Consult your doctor or healthcare provider for medical advice before making changes to your supplement regimen or lifestyle.
