Understanding the Risks: Why is too much vitamin B6 bad for you?

October 13, 2025 •

3 min read

According to reports from medical bodies like the Australian Therapeutic Goods Administration (TGA), cases of peripheral neuropathy linked to supplemental vitamin B6 intake are on the rise, highlighting the severe consequences of high doses. So, why is too much vitamin B6 bad for you and how can you avoid its harmful effects?

Quick Summary

Excessive intake of vitamin B6, almost exclusively from high-dose supplements, can cause toxicity. The most significant health risk is peripheral neuropathy, which involves nerve damage leading to numbness, tingling, and poor coordination. While vital in proper amounts, high levels interfere with nerve function and can cause long-term, sometimes irreversible, harm.

Key Points

Peripheral Neuropathy Risk: The most serious side effect of too much vitamin B6 from supplements is nerve damage, causing numbness, tingling, and pain in the hands and feet.
Supplements are the Main Cause: Toxicity is almost exclusively linked to high-dose vitamin B6 supplements, not consuming foods rich in B6.
Symptoms of Overdose: Watch for sensory changes, muscle weakness, difficulty with balance, painful skin lesions, and gastrointestinal distress.
Variable Tolerance: Some people can experience symptoms of toxicity at doses below the 100 mg/day upper limit, particularly with prolonged use.
Prioritize Food Sources: The safest and most effective way to obtain vitamin B6 is through a balanced diet, which includes foods like fish, poultry, chickpeas, bananas, and potatoes.
Discontinue Supplements: If toxicity is suspected, stopping the supplement is the primary treatment, which often leads to gradual symptom improvement.

What is Vitamin B6 and its Role?

Vitamin B6 is a water-soluble vitamin essential for numerous bodily functions, playing a crucial role in over 100 enzyme reactions. It is vital for protein metabolism, energy production, brain development, and the creation of neurotransmitters. As a water-soluble vitamin, any excess B6 from a food-based diet is typically excreted in the urine, making toxicity from dietary sources highly unlikely.

There are several forms of vitamin B6, but the most common one found in supplements is pyridoxine hydrochloride. The body must convert this inactive form into its active, coenzyme form, pyridoxal 5'-phosphate (PLP), to be utilized.

The Dangers of Excessive Intake

The most significant and well-documented risk of excessive vitamin B6 intake is the development of peripheral neuropathy, a type of nerve damage. This condition affects the nerves outside the brain and spinal cord, typically causing sensory abnormalities and pain. While the exact mechanism is still under investigation, it is believed that very high levels of pyridoxine from supplements can disrupt the normal metabolism of the active B6 form, interfering with nerve function and causing neurotoxicity.

The risk of toxicity increases with the dose and duration of supplementation. While the Tolerable Upper Intake Level (UL) for adults is set at 100 mg per day in the U.S., some individuals have developed symptoms at much lower doses, especially with prolonged use. In fact, some regulatory bodies have lowered their recommended daily limits and added warnings for products containing more than 10mg. This indicates that the risk can vary significantly from person to person.

Recognizing the Symptoms of B6 Toxicity

Symptoms of vitamin B6 toxicity often affect the nervous system and can progress if the excessive supplementation continues. Key signs to watch for include:

Sensory Changes: Numbness, tingling, or burning sensations in the hands and feet. This is a classic symptom of peripheral neuropathy and is sometimes described as a 'stocking-glove' pattern.
Motor Impairment: A loss of coordination, muscle weakness, and difficulty with balance and walking.
Skin Lesions: Painful or disfiguring skin patches, and increased sensitivity to sunlight (photosensitivity).
Gastrointestinal Issues: Nausea, heartburn, and abdominal pain are also reported side effects.

It is important to note that the neurological symptoms of B6 toxicity can be similar to those of a B6 deficiency, which can complicate diagnosis. A doctor's evaluation, including a review of all supplements being taken, is essential for accurate identification.

Safe Intake vs. Dangerous Overdose

The key distinction in managing vitamin B6 intake lies in the source. Consuming B6 from whole foods is safe and beneficial, whereas high-dose supplements carry significant risks.

Comparison: Vitamin B6 from Food vs. Supplements


Feature	B6 from Food Sources	B6 from Supplements
Toxicity Risk	Extremely low. Body excretes excess.	High, especially with high doses and long-term use.
Source	Wide variety of foods like chickpeas, tuna, salmon, chicken, bananas, potatoes, and fortified cereals.	Concentrated, often synthetic, pyridoxine hydrochloride.
Absorption	Bioavailable as part of a varied diet.	Can lead to high concentrations that overwhelm metabolic processes.
Recommended Intake	Easily met through a balanced diet (e.g., 1.3-1.7 mg/day for most adults).	Doses often exceed the Recommended Dietary Allowance (RDA) significantly.
Body's Response	Body uses what it needs and discards the rest.	High levels can interfere with active B6 and harm nerves.

What to Do in Case of Suspected Toxicity

If you experience any symptoms of peripheral neuropathy and take B6 supplements, the first and most critical step is to stop taking them immediately. In most cases, symptoms will gradually improve after cessation, although recovery can be slow and nerve damage can sometimes be permanent.

Consulting a healthcare professional is vital for proper diagnosis and management. They may perform neurological exams and blood tests to confirm toxicity and rule out other causes of neuropathy, such as diabetes. Physical therapy and other supportive care may be necessary to manage lingering symptoms.

Conclusion

While vitamin B6 is an indispensable nutrient for good health, the adage 'more is better' does not apply. The risks of excessive B6 intake are primarily a concern for those taking high-dose supplements, not from dietary sources. The potential for serious nerve damage, known as peripheral neuropathy, underscores the importance of exercising caution with over-the-counter supplements. Always prioritize getting your nutrients from a balanced, varied diet, and only take supplements under the guidance of a healthcare professional, especially if taking higher doses. More information on vitamins can be found on authoritative health websites such as the NIH Office of Dietary Supplements.

Frequently Asked Questions

No, it is highly unlikely to get too much vitamin B6 from food alone. Your body efficiently regulates and excretes any excess B6 consumed through your diet.

For most adults aged 19-50, the recommended daily allowance (RDA) is 1.3 mg. The RDA slightly increases for older adults, with men over 50 needing 1.7 mg and women needing 1.5 mg.

The Tolerable Upper Intake Level (UL) for adults in the U.S. is 100 mg per day. However, it's important to know that nerve damage has been reported at doses below this level in some individuals.

Symptoms of B6 toxicity usually appear after consuming high doses of supplements for an extended period, often several months or longer. The timeline and severity can vary from person to person.

Early signs of vitamin B6 toxicity often include sensory disturbances like numbness, tingling, or a burning sensation in the hands and feet due to peripheral neuropathy.

In some cases, prolonged exposure to high doses of vitamin B6 can cause irreversible nerve damage. However, symptoms typically improve or resolve after discontinuing the supplement, though recovery can be a slow process.

Taking multiple supplements that all contain vitamin B6 can lead to an unknowingly high daily intake and increase the risk of toxicity. Always check all supplement labels and consider your total daily consumption.

The primary treatment is to stop taking all supplements containing vitamin B6. A healthcare provider will monitor your condition and may suggest supportive therapies like physical therapy to address symptoms.