What Do High Levels of Vitamin B6 Do to Your Body?

October 31, 2025 •

3 min read

While the average daily intake of vitamin B6 from food is about 1.9 mg, health risks can arise from excessive intake of supplements. A high level of vitamin B6, most often caused by long-term, high-dose supplementation, can lead to nerve damage, a condition known as peripheral neuropathy.

Quick Summary

Taking too much vitamin B6 from supplements can damage nerves, causing symptoms like numbness, tingling, and pain, mainly in the hands and feet. This condition, peripheral neuropathy, can sometimes be permanent, though symptoms often improve after discontinuing supplementation.

Key Points

Source of Toxicity: High levels of vitamin B6, which can cause toxicity, are almost exclusively from excessive supplemental intake, not from food.
Nerve Damage (Neuropathy): The most serious side effect is peripheral neuropathy, characterized by nerve damage that can cause numbness, tingling, and pain in the hands and feet.
Other Symptoms: Excessive B6 can also lead to ataxia (lack of coordination), skin lesions, photosensitivity, nausea, and heartburn.
Dosage Matters: The potential for toxicity is related to the amount consumed.
Unintentional Overdose: Taking multiple supplements containing vitamin B6, such as a multivitamin and a magnesium supplement, can result in an unintentional overdose.
Reversibility: While symptoms often improve after discontinuing supplements, the recovery can be slow, and nerve damage may be permanent in some cases.

The Role of Vitamin B6

Vitamin B6, also known as pyridoxine, is a vital water-soluble nutrient involved in numerous metabolic processes, including the metabolism of carbohydrates, fats, and amino acids. It is essential for brain function and nerve health, supporting the production of neurotransmitters and hemoglobin. A balanced diet provides adequate B6, with good sources including fish, poultry, chickpeas, potatoes, and bananas.

The Danger of Excessive Supplementation

The primary risk of high vitamin B6 levels stems from excessive and prolonged supplement use, not from dietary intake. Although B6 is water-soluble and the body typically excretes excess amounts, high-dose supplements can lead to a toxic buildup. Most cases of B6 toxicity are linked to supplements providing doses significantly exceeding the recommended daily intake, and accidental overdose can occur by combining multiple B6-containing supplements.

Peripheral Neuropathy: The Main Concern

The most serious consequence of high vitamin B6 levels is sensory peripheral neuropathy, which is damage to the nerves outside the brain and spinal cord that transmit sensory information. Symptoms vary in severity based on dosage and duration of exposure and commonly affect the hands and feet.

Common signs of peripheral neuropathy include:

Numbness and tingling: A 'pins and needles' feeling, often in the extremities.
Pain or burning sensations: Can be a significant symptom.
Difficulty walking or unsteady gait: Due to impaired positional sense and muscle control (ataxia).
Reduced sensory abilities: Difficulty sensing pain or temperature changes.
Muscle weakness: In some instances, motor nerves are also affected.

Other Symptoms of High Vitamin B6 Levels

In addition to peripheral neuropathy, excessive supplemental B6 intake can cause other side effects:

Photosensitivity: Increased sensitivity to sunlight.
Skin lesions: Painful skin patches.
Gastrointestinal issues: Nausea and heartburn.
Cognitive changes: Potential cognitive issues have been reported.

Comparison: Food-Based B6 vs. Supplements


Feature	Food-Based Vitamin B6	Supplemental Vitamin B6
Source	Naturally in foods.	Concentrated forms in supplements.
Risk of Toxicity	Virtually zero.	High risk with prolonged, high-dose use.
Concentration	Balanced with other nutrients.	Can contain very high doses.
Absorption	Gradual.	Rapid, high-dose absorption.
Cumulative Intake	Within safe limits from food.	Risk from multiple supplements.

Management and Prognosis

The primary treatment for B6 toxicity is to immediately stop all B6-containing supplements. Early discontinuation is crucial for better outcomes. Symptoms often improve, but recovery can be slow, taking months or years. In some cases, especially with high or prolonged exposure, nerve damage may be permanent. Medical management, including pain relief and physical therapy, may aid recovery. It is vital to seek medical advice if B6 toxicity is suspected. Regulations for B6 supplements have been updated to address these risks.

Conclusion

High vitamin B6 levels and associated health risks, particularly peripheral neuropathy, are almost exclusively linked to excessive intake from dietary supplements. Symptoms like numbness, tingling, and pain can occur, and nerve damage may sometimes be permanent. Awareness of supplement contents and potential toxicity symptoms is crucial for prevention. Always consult a healthcare professional before starting high-dose vitamin supplements.

Frequently Asked Questions

No, it is nearly impossible to consume toxic levels of vitamin B6 from a food-based diet alone. All reported cases of toxicity are linked to high-dose supplementation.

The initial signs of vitamin B6 toxicity typically involve the nervous system, with symptoms such as numbness, tingling, or a burning sensation in the hands and feet. This is known as peripheral neuropathy.

Health authorities have established tolerable upper intake levels for vitamin B6 to help prevent adverse effects. Exceeding these levels, particularly through supplementation, increases the risk of toxicity.

The primary treatment is to immediately stop taking all supplements containing vitamin B6. Symptomatic treatment, such as pain relief or physical therapy, may be used for managing continued effects.

Recovery can be slow and varies depending on the amount and duration of supplementation. In many cases, symptoms gradually improve over several months to a year after discontinuing the supplement, but some individuals may experience permanent nerve damage.

Vitamin B6 in food is less concentrated and balanced with other nutrients, posing no risk of toxicity. In contrast, supplements contain concentrated, isolated forms of B6, which can be toxic at high doses.

Yes, other potential adverse effects include skin problems like painful lesions and photosensitivity, as well as gastrointestinal issues such as nausea and heartburn.