What Happens if I Take Too Much Vitamin B6? Understanding the Risks of Toxicity

October 15, 2025 •

4 min read

Reports have circulated about severe reactions from over-the-counter vitamin B6 supplements, prompting regulatory warnings. So, what happens if I take too much vitamin B6? Excessive intake, especially from supplements, can lead to a condition known as peripheral neuropathy, affecting the nervous system.

Quick Summary

Excessive vitamin B6 intake, typically from supplements, can cause toxicity resulting in nerve damage, numbness, tingling, and poor coordination. Recovery often follows cessation of supplementation, though effects may be long-term or, in rare cases, permanent.

Key Points

Source of Toxicity: Vitamin B6 toxicity is almost exclusively caused by excessive intake from supplements, not from food sources.
Primary Risk: The main risk is peripheral neuropathy, which involves damage to nerves outside the brain and spinal cord.
Key Symptoms: Symptoms include numbness, tingling, burning pain, and poor coordination (ataxia), often starting in the hands and feet.
Dosage Matters: While the adult Tolerable Upper Intake Level (UL) is 100 mg per day, toxicity can occur at lower doses over time, especially with long-term supplementation.
What to Do: If you suspect B6 toxicity, stop taking all supplements containing the vitamin and consult a healthcare provider immediately.
Potential for Permanent Damage: Recovery can be slow, taking months to years, and in severe or prolonged cases, some nerve damage may be irreversible.

Vitamin B6 is a crucial water-soluble vitamin involved in over 100 enzymatic reactions in the body, including metabolism, nerve function, and the formation of red blood cells. However, while essential, it is possible to have too much of a good thing. Consuming excessive amounts of B6, almost exclusively from supplements, can lead to serious adverse effects.

The Risks of Vitamin B6 Toxicity

Unlike fat-soluble vitamins, which can be stored in the body's fatty tissues, B6 is water-soluble. Any excess is usually excreted through urine. However, when taking high-dose supplements over an extended period, the body cannot process the excess quickly enough, leading to a build-up in the bloodstream and toxicity. The most significant health risk associated with high-dose B6 is damage to the nervous system, known as peripheral neuropathy.

Symptoms of Vitamin B6 Overdose

The symptoms of B6 toxicity typically involve the nervous system but can affect other bodily functions as well. It's important to be aware of these signs, especially if you take vitamin supplements regularly.

Neurological Symptoms (Peripheral Neuropathy)

Numbness and tingling: Often starting in the hands and feet, described by some as a "stocking-glove" sensation.
Difficulty walking or unsteady gait (ataxia): Caused by a lack of muscle control or coordination.
Pain or burning sensations: In the hands, feet, or other areas.
Muscle weakness: Particularly in the legs.
Reduced sensation: A decreased ability to feel pain or extreme temperatures.

Other Symptoms

Painful skin lesions: Can be disfiguring.
Heartburn and nausea: Gastrointestinal distress.
Photosensitivity: Sensitivity to sunlight.
Fatigue and cognitive changes: Some patients report brain fog and memory lapses.
Mood changes: Anxiety and depression have been reported in some cases of megavitamin B6 syndrome.

Understanding the Safe Doses: RDA vs. UL

The risk of toxicity is directly related to dosage and duration. Health authorities provide guidelines to help consumers and practitioners understand the difference between recommended daily intake and the upper limit.


Feature	Recommended Dietary Allowance (RDA)	Tolerable Upper Intake Level (UL)
Definition	Average daily level of intake sufficient to meet the nutrient requirements of nearly all healthy people.	The maximum daily intake unlikely to cause adverse health effects.
Adult Daily Dose	Approximately 1.3 to 1.7 mg.	100 mg in the US, though toxicity can occur at lower doses.
Toxicity Risk	Extremely low risk from food sources.	Toxicity is a significant concern, especially with long-term supplementation above this level.
Source	Primarily from food sources like chickpeas, beef liver, fish, and potatoes.	Almost exclusively from high-dose supplements.

The Mechanism of B6 Neurotoxicity

While the exact mechanism is still under investigation, researchers believe that high levels of supplemental B6 (pyridoxine) can interfere with the body's natural B6 metabolism. Specifically, excessive pyridoxine can competitively inhibit the active form of the vitamin, pyridoxal-5'-phosphate (PLP), potentially causing a state that mimics deficiency despite high blood levels. It is also suspected that high doses can disrupt neurotransmitter activity, leading to nerve over-excitation and damage.

Who Is Most at Risk?

While toxicity was historically associated with megadoses, recent case reports show that it can also occur with lower-dose supplements taken over a long period. Individuals who unknowingly consume high amounts of B6 from multiple sources, such as a multivitamin, a magnesium supplement, and an energy drink, are at risk. The risk can also vary based on individual metabolism and genetic predispositions.

What to Do If You Suspect Toxicity

If you experience symptoms of peripheral neuropathy and regularly take B6 supplements, the primary treatment is to stop all supplementation immediately. Consulting a healthcare provider is essential for an accurate diagnosis, which may involve a review of your supplement history, a physical exam, and blood tests.

Treatment often involves managing symptoms as the body clears the excess vitamin. This can include physical therapy to improve strength and coordination, and medication to manage neuropathic pain. In some cases, such as those with extremely high dosages, the effects may be permanent. However, many people experience a slow, gradual improvement, though full recovery can take months or years.

Conclusion

While vitamin B6 is vital for health, taking excessive amounts from supplements can have serious consequences, most notably peripheral neuropathy. The key to prevention is moderation and awareness of your intake. The Recommended Dietary Allowance (RDA) is easily met through a balanced diet, and most people do not need additional supplements unless a deficiency is diagnosed by a medical professional. Always check supplement labels, especially for combination products, to ensure you are not unknowingly exceeding the safe tolerable upper intake level.

For more information on vitamin B6, consult the fact sheet provided by the National Institutes of Health: Vitamin B6 - Health Professional Fact Sheet

Frequently Asked Questions

For most adults, the Tolerable Upper Intake Level (UL) is 100 mg per day, although toxicity has been reported in individuals taking lower doses over a long period. It is always best to consult a healthcare provider for personalized advice.

No, it is highly unlikely to develop vitamin B6 toxicity from dietary sources alone. The excess vitamin from food is efficiently excreted by the body.

Early signs of a B6 overdose often include numbness and tingling, frequently in the hands and feet. This can progress to burning pain, muscle weakness, and a lack of coordination.

In many cases, symptoms of peripheral neuropathy improve or resolve completely after discontinuing high-dose B6 supplements. However, recovery can be slow, and in some severe cases, the nerve damage may be permanent.

Diagnosis involves a medical history review, including supplement intake, a physical and neurological exam, and blood tests. Treatment consists primarily of stopping all B6 supplementation and managing symptoms with supportive care, such as physical therapy or pain medication.

Always read the label of any vitamin or supplement product carefully. B6 is often listed by its chemical name, pyridoxine. Pay attention to the dosage per serving and be aware that B6 is often included in multivitamins, magnesium supplements, and energy drinks.

In some rare cases, individuals have developed toxicity from relatively low doses of B6, especially with prolonged use. This highlights the importance of not taking supplements unless medically necessary and monitoring for any unusual symptoms.