Image source: 7News Australia
You’d think a humble vitamin couldn’t potentially impact your nervous system — but Blackmores is now facing a B6 class action in Australia over alleged vitamin toxicity. Dozens of Australians claim their Blackmores B6 supplements caused peripheral neuropathy, nerve pain, and long-term disability.
One of the lead plaintiffs? A young father who now struggles to walk after unknowingly stacking multiple Blackmores B6 products. His diagnosis: peripheral neuropathy — a neurological condition that mimics MS — reportedly triggered by excess B6 from TGA-approved Blackmores supplements, including common prenatal and multivitamin blends.
While just one official lawsuit has been filed so far, lawyers say over 140 people have come forward, with more joining weekly. The proposed Blackmores B6 legal case in Australia could become one of the nation’s biggest supplement-related class actions — all centred on B6 nerve toxicity and a lack of proper warnings.
Blackmores denies responsibility, but plaintiffs argue consumers were never clearly warned about the risks of B6 toxicity, especially when combining protein powders, pre-natals, or multivitamins.
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When Wellness Goes Wrong
B6 is water-soluble, which most people assume means “flushes out, can’t overdose.” But that’s the trap. Long-term use, even below 200mg/day, can cause nerve damage, especially in people who supplement without checking for ingredient overlap.
This unintentional overuse is where people combine several products without realising they’re stacking megadoses and it's a form of what’s known as macrodosing.
What Is Macrodosing — and Why It Can Be Risky
“Macrodosing” refers to taking very high doses of a supplement or compound, often well above the standard daily requirement and usually to target a specific health outcome.
Some functional and integrative practitioners may recommend short-term macrodosing for things like adrenal recovery, mitochondrial support, or mood. But it’s not something to self-prescribe, especially with vitamins like B6, B12, D, or iron, which can accumulate or cause harm when misused.
Why It Can Be Dangerous
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Water-soluble doesn’t mean harmless — vitamins like B6 and B12 can overwhelm the system at high doses
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Genetic differences matter — MTHFR, COMT, and detox SNPs change how your body processes nutrients
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Liver, kidneys, and nervous system can be affected
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Stackable exposure is common — people accidentally macrodose without realising it
How to Do It Safely
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Get your bloods done first — check levels of B6, B12, folate, D, iron, and homocysteine
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Consider gene testing — especially if you have chronic fatigue, neurological symptoms, or sensitivity to supplements
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Track your symptoms — energy, skin, mood, and sleep can offer early warnings
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Work with a practitioner — functional medicine clinicians can guide targeted and safe dosing strategies
Supplements That May Turn Toxic if Overused
| Supplement | Risk If Overused | Symptoms to Watch For |
|---|---|---|
| Vitamin B6 | Neurotoxicity | Tingling, nerve pain, loss of balance |
| Vitamin A | Liver stress, birth defects | Vision issues, fatigue, headaches |
| Iron | Organ damage (in non-deficient users) | Gut pain, nausea, liver overload |
| Zinc | Immune suppression, copper depletion | Metallic taste, cramps, fatigue |
| Selenium | Toxicity, hair loss | Nail brittleness, garlic breath, nausea |
| Vitamin D | Kidney and calcium issues | Confusion, irregular heartbeat, calcification |
| Vitamin B12 | Overstimulation (in sensitive users) | Acne, insomnia, anxiety, heart palpitations |
The information provided here is for educational purposes only and refers to potential side effects observed at high or prolonged dosages. Always follow product label instructions and consult a healthcare practitioner for personalised advice.
What You Can Do
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Read the labels — don’t stack unknowingly
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Start low, go slow — especially with methylated Bs
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Get your bloods done regularly — look beyond standard ranges
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Check your genetics if you have MTHFR or COMT variants
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See a functional medicine practitioner who understands root causes, not just symptom Band-Aids — Functional Medicine & Wellness Clinics →
Watch the Full Story
Video courtesy of 7News Australia
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Disclaimer: This article is for informational purposes only and does not constitute medical or legal advice. It reflects information publicly available at the time of publication, including claims made in an ongoing legal proceeding. Readers should consult qualified healthcare practitioners before making changes to supplement use.
Article Dated: 21 July 2025
