Can vitamin B6 build up in your system? Understanding vitamin B6 toxicity

October 11, 2025 •

3 min read

While often viewed as harmless due to its water-soluble nature, excessive intake of vitamin B6, usually through supplements, can indeed lead to a build-up in the body and cause a toxic condition called peripheral neuropathy. This happens when the cumulative dose over time exceeds the body's capacity for elimination, affecting nerve function.

Quick Summary

Vitamin B6, commonly sourced from supplements, can accumulate in the body over time at high doses. This accumulation can lead to toxicity, resulting in nerve damage and a range of adverse health effects.

Key Points

Toxicity from Supplements: High-dose vitamin B6 supplements, not dietary intake, are the primary cause of build-up and toxicity.
Peripheral Neuropathy: Excess B6 damages peripheral nerves, causing symptoms like numbness, tingling, and pain, especially in the hands and feet.
Body Storage: Despite being water-soluble, vitamin B6 can accumulate in body tissues, including the liver and muscles, prolonging its presence in the system.
Check All Labels: B6 is present in many products, including multivitamins and magnesium supplements, so checking all labels is crucial to track total intake.
Recovery Can Be Slow: After stopping supplements, recovery can take months or years, and some nerve damage may be permanent.
Coasting Effect: Symptoms may temporarily worsen in the weeks following the cessation of B6 supplements before gradual improvement begins.
Different Tolerable Limits: Safe upper limits (ULs) for vitamin B6 can vary by country, with some agencies recommending a much lower threshold than others.

What is Vitamin B6 and How Is It Processed?

Vitamin B6 is essential for numerous bodily processes, including metabolism and neurotransmitter creation. While typically considered water-soluble and excreted in urine, B6 can be stored in tissues, particularly muscles and the liver. This storage, combined with a relatively long half-life of two to four weeks, allows it to accumulate over time with consistent high-dose intake, leading to toxicity, also known as hypervitaminosis B6.

The Path to Vitamin B6 Toxicity

Toxicity from vitamin B6 is almost exclusively caused by high-dose supplements, not from food sources like chickpeas or bananas. Many supplements, including multivitamins and B-complexes, contain B6 in amounts significantly exceeding the Recommended Dietary Allowance (RDA). Taking multiple supplements can quickly lead to a dangerously high daily intake.

Symptoms of Excess Vitamin B6: Peripheral Neuropathy

High levels of vitamin B6 can cause peripheral neuropathy, damaging the nerves outside the brain and spinal cord. Symptoms can be neurological and non-neurological. Neurological symptoms include numbness, tingling, burning pain in the limbs (often in a 'stocking-glove' pattern), difficulty with coordination, and muscle weakness. Non-neurological symptoms can include skin lesions, photosensitivity, nausea, and dizziness. It's worth noting that some symptoms of B6 toxicity can resemble those of a deficiency.

Comparing Recommended Intake vs. Upper Limit

The following table illustrates the difference between safe and potentially toxic levels of vitamin B6 based on the U.S. Recommended Dietary Allowance (RDA) and Upper Tolerable Intake Level (UL).


Life Stage	RDA (mg/day)	UL (mg/day)	Primary Concern	Common Source of Toxicity
Adults 19–50	1.3	100	Neurotoxicity	Supplements (>100 mg/day)
Adults 51+ (Men)	1.7	100	Neurotoxicity	Long-term high-dose supplements
Adults 51+ (Women)	1.5	100	Neurotoxicity	Combination supplement intake
Children 1–3 years	0.5	30	Neurotoxicity	Supplement overdose
Children 4–8 years	0.6	40	Neurotoxicity	Accidental overdose

It's important to be aware that some international health authorities recommend even lower ULs than those in the U.S..

Diagnosis and Treatment of Vitamin B6 Toxicity

Diagnosing B6 toxicity involves reviewing supplement use, a physical and neurological exam, and blood tests. The primary treatment is to immediately stop all B6 supplements. There is no specific cure. After stopping supplements, symptoms may temporarily worsen for a few weeks (the 'coasting' effect) before gradually improving. Full recovery can take months or years as nerves heal, but severe, long-term exposure may result in permanent nerve damage. Supportive care like pain management and therapy can help manage symptoms during recovery.

Prevention is Key

Preventing vitamin B6 toxicity requires careful attention to supplement intake. Always check labels for various forms of B6 (pyridoxine, pyridoxal, pyridoxamine). A balanced diet typically provides sufficient B6 without risk of toxicity. If considering supplements, consult a healthcare professional to determine the appropriate dosage and avoid excessive intake.

Conclusion

While vital for health, vitamin B6 can build up to toxic levels if consumed excessively through supplements, leading to potentially irreversible nerve damage. Understanding the difference between the RDA and UL and monitoring all sources of B6 intake are crucial for prevention. Promptly stopping supplements is the most important step for those experiencing symptoms. For more information, the National Institutes of Health provides fact sheets on vitamin B6.

Frequently Asked Questions

No, it is extremely difficult and almost unheard of to develop vitamin B6 toxicity from dietary sources alone. Reported cases are exclusively linked to high-dose supplementation.

Early symptoms often manifest as peripheral neuropathy, including numbness, tingling, or a burning sensation, most frequently in the hands and feet.

After stopping supplementation, it can take months or even years for vitamin B6 levels to normalize and for symptoms to resolve, though some nerve damage may be permanent.

The main treatment for vitamin B6 toxicity is to immediately cease all intake of supplements containing B6. There is no specific antidote, and management focuses on symptom relief and allowing the body time to clear the excess vitamin.

Yes, it is possible. Many multivitamins and other combination supplements contain high doses of vitamin B6. Taking multiple supplements unknowingly can lead to an excessive total daily intake, increasing the risk of toxicity.

In the U.S., the adult tolerable upper intake level (UL) is set at 100 mg per day. However, it's worth noting that some European agencies recommend a much lower UL of 12 mg per day, and neuropathy can occur at doses lower than 50 mg for some individuals.

While symptoms often improve after stopping supplementation, especially if caught early, high or prolonged exposure to excessive doses of vitamin B6 can lead to irreversible nerve damage in some cases.