Vitamin B6 Toxicity: Symptoms, Risks & How to Avoid Peripheral Neuropathy

Vitamin B6 toxicity has recently gained attention in the media due to proposed changes to its regulation by the Therapeutic Goods Administration (TGA).

While vitamin B6 is essential for nerve, brain, and immune health, taking too much (especially through supplements) can be harmful.

In this blog post, we’ll cover what vitamin B6 toxicity is, how it can cause peripheral neuropathy, and why self-prescribing supplements can be dangerous.

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What is the TGA?

The Therapeutic Goods Administration (TGA) is Australia’s regulator for medicines, supplements, and medical devices. Their role is to ensure that products sold to the public are safe, effective, and of high quality.

TGA Status on Vitamin B6

The TGA has proposed new rules for vitamin B6 in supplements:

• Up to 50 mg/day: Allowed in over-the-counter supplements.

• 50–200 mg/day: Available only through a pharmacist (Schedule 3).

• 200 mg/day or more: Prescription-only (Schedule 4).

Since 2022, any product with more than 10 mg/day must carry a warning about the risk of nerve damage, called peripheral neuropathy, and include the symptoms to watch for.

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What is Peripheral Neuropathy?

Peripheral neuropathy happens when the nerves outside your brain and spinal cord aren’t functioning properly.

This can cause:

• Tingling, burning, or numbness

• Pain or weakness in hands and feet

• Balance problems or poor coordination

• Sometimes digestive or bladder issues

Symptoms often start in the fingers and toes and may gradually spread upward in a “stocking-glove” pattern.

Causes of Peripheral Neuropathy

Most common causes:

• Diabetes and metabolic syndrome – the leading cause worldwide

• Alcohol misuse – long-term heavy drinking

• Vitamin and mineral deficiencies – especially B12, B1, B6, vitamin E, copper

• Medications – e.g., chemotherapy, some antibiotics

• Injuries or nerve compression – accidents, repetitive strain, slipped discs

Less common but significant causes:

• Autoimmune conditions – e.g., Sjögren’s syndrome, Guillain-Barré syndrome, rheumatoid arthritis, lupus

• Infections – shingles, HIV, hepatitis B & C, Lyme disease

• Vitamin B6 toxicity – from high-dose supplements

Rare causes:

• Cancer or tumors

• Bone marrow disorders – e.g., myeloma, lymphoma

• Exposure to toxins – heavy metals or industrial chemicals

• Inherited disorders – e.g., Charcot-Marie-Tooth disease

• Idiopathic – no identifiable cause

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Vitamin B6 Toxicity

Vitamin B6 toxicity is rare, but it can lead to peripheral neuropathy.

How toxicity occurs: Excess B6 can damage nerve cells and interfere with the active form of B6 (P5P), sometimes causing toxicity symptoms that mimic a deficiency.

Forms that can cause toxicity: All forms of vitamin B6 can be harmful in high doses. This includes Pyridoxine, pyridoxal, and pyridoxamine.

Symptoms of Vitamin B6 Toxicity:

• Tingling, burning, numbness, or pain in hands and feet (paraesthesia), often spreading in a “stocking-glove” pattern (from toes up, then fingers up)

• Balance problems

• Muscle weakness

• Bone pain.

Safe Dosage & Risk Thresholds

• High-risk doses: 500–1,000 mg/day over months.

• Lower doses: Even smaller amounts can accumulate over 6–9 months and cause toxicity.

• Dietary intake alone is safe: Only supplements or fortified foods can cause excess.

• TGA warning thresholds: over 50 mg/day may require pharmacist supervision.

• Recovery: Symptoms often improve after stopping supplementation, but recovery can be slow.

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Why Self-Prescribing Can Be Dangerous

Many over-the-counter supplements contain low doses of vitamin B6, and taking multiple products without guidance can unintentionally exceed safe levels. Self-prescribing increases the risk of peripheral neuropathy, slow recovery, and, in rare cases, lasting nerve damage.

Real-world example:

One patient had B6 levels 36 times above normal due to multivitamins and magnesium supplements!

This highlights that even over-the-counter products can be risky if self-prescribed over time.

Working with a qualified naturopath ensures that:

✓ Your total B6 intake is safe

✓ You understand the potential risks

✓ Symptoms are monitored early, and blood tests are interpreted correctly

✓ You receive personalised guidance for your health goals, reducing intake of unnecessary supplements

What to Do

1. Check your supplements: Know exactly how much B6 you are taking across all supplements.

2. Talk to your practitioner: Share all supplements to track intake.

3. Know your dose: Follow dosage instructions carefully.

4. Watch for symptoms: Tingling, numbness, or weakness may indicate toxicity.

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My Position as a Naturopath

I support the TGA’s proposed changes to vitamin B6 because they protect public safety.

As a naturopath, I am trained in safe vitamin dosing and can help you get the benefits of B6 without risking nerve damage.

Together, we can make sure your supplements are both safe and effective.