Can too much B vitamins cause neuropathy?

October 27, 2025 •

3 min read

While the B vitamins are vital for human health, excessive intake of certain B vitamins, specifically vitamin B6, is a known cause of peripheral neuropathy. A healthy and varied diet provides sufficient B vitamins for most people, but high-dose supplements can accumulate in the body and lead to nerve damage over time.

Quick Summary

Peripheral neuropathy can be caused by consuming high doses of vitamin B6, usually from supplements, over an extended period. Symptoms include numbness, tingling, and pain in the hands and feet. This neurotoxicity is distinct from deficiencies and can sometimes be permanent.

Key Points

Vitamin B6 is the main concern for neuropathy: Unlike most other B vitamins, excessive intake of vitamin B6, typically from supplements, is a known cause of peripheral neuropathy.
High doses and long-term use increase risk: The risk of B6 toxicity and nerve damage is significantly higher with chronic, high-dose supplementation, though sensitivity varies between individuals.
Symptoms include numbness and tingling: B6-induced neuropathy commonly presents as numbness, tingling, burning pain, and muscle weakness, often in the hands and feet.
Toxicity is rare from food: Excessive vitamin B6 levels and subsequent neuropathy are almost always caused by supplement use, not from food sources.
Folate can mask B12 deficiency: High intake of folic acid from supplements can hide the blood-related symptoms of a vitamin B12 deficiency, potentially allowing the associated neurological damage to worsen.
Stopping supplementation is key: The primary treatment for B6 toxicity is to stop taking the supplements, though recovery may be slow and some damage could be permanent.

The Link Between B Vitamins and Neuropathy

Neuropathy is a medical condition characterized by nerve damage, which can lead to weakness, numbness, and pain, most commonly in the hands and feet. While a deficiency in certain B vitamins, notably B12, can cause neuropathy, it is also well-documented that an excess of specific B vitamins can cause a similar condition. The key culprit in supplement-induced neuropathy is vitamin B6.

Vitamin B6: The Primary Concern

Among the eight B vitamins, B6 (pyridoxine) is the one most strongly associated with toxicity-induced neuropathy. This occurs with excessive, prolonged intake of B6, typically from supplements, as toxicity from dietary sources is rare. The risk of neuropathy increases with chronic intake, even at moderate doses, with neurological symptoms potentially appearing with long-term intake. Some sensitive individuals may experience symptoms at lower doses.

The Mechanism of B6 Toxicity

The exact way excessive B6 causes nerve damage is still being studied. One theory suggests high levels of pyridoxine from supplements may inhibit key enzymes, disrupting neurotransmission and potentially leading to nerve degeneration in the peripheral nervous system. Pyridoxine's limited ability to cross the blood-brain barrier means its toxic effects are mainly in the peripheral nerves.

Symptoms of B6-Induced Neuropathy

Symptoms of B6 toxicity resemble those of other peripheral neuropathies and may include:

Numbness and Tingling: Often in a stocking-glove pattern in the hands and feet.
Pain and Burning: Sensation in the extremities.
Ataxia: Difficulty with balance and walking.
Muscle Weakness: Reduced strength, particularly in the hands and feet.
Loss of Coordination: Impaired fine motor skills.

Immediate medical attention is advised for anyone experiencing these symptoms while taking B6 supplements. Stopping the supplement is the main treatment, and while symptoms often improve, permanent nerve damage is possible.

Other B Vitamins and Neuropathy Concerns

While B6 is the primary concern for excess-induced neuropathy, other B vitamins have potential risks or can affect neurological health in excess. Most B vitamins are water-soluble and excess is typically excreted. However, there are exceptions.

Folic Acid and Vitamin B12

High intake of folate (B9) from supplements can conceal the symptoms of a B12 deficiency. Undiagnosed B12 deficiency can lead to severe neurological damage and neuropathy. High folate levels can hide the anemia associated with B12 deficiency, delaying diagnosis and treatment of nerve damage.

Niacin and Other B Vitamins

Excess niacin (B3) can cause liver damage but typically not neuropathy. Other B vitamins, like B1 and B2, are generally considered non-toxic even at high doses, with excess B2 simply causing bright yellow urine.

Comparison: Neuropathy from Deficiency vs. Excess

Distinguishing between neuropathy caused by a vitamin deficiency and excess is vital for treatment. High-dose B vitamin supplementation should be medically supervised.


Feature	Neuropathy from B12 Deficiency	Neuropathy from B6 Excess
Cause	Lack of intrinsic factor, diet, absorption issues	High-dose B6 supplementation
Symptom Pattern	Often includes anemia, cognitive issues, and gait problems.	Primarily sensory symptoms: numbness, tingling, pain, loss of coordination.
Treatment	B12 injections or high-dose oral supplements.	Immediate cessation of B6 supplements.
Reversibility	Treatment can halt progression, but existing nerve damage may not fully reverse.	Symptoms often improve, but permanent damage is possible.
Prevention	Adequate dietary intake, or B12 supplements for at-risk individuals.	Avoiding high-dose B6 supplements unless medically necessary and supervised.

Conclusion: Taking B Vitamins Responsibly

While B vitamins are crucial for health, taking excessive amounts, especially B6, is not beneficial and can be harmful. Supplementation should not be taken lightly. The risks of high-dose B6, and potentially high folate, underscore the need to consult a healthcare professional before starting any supplement regimen. A balanced diet provides sufficient B vitamins for most people. For those with deficiencies, medical guidance ensures safe and effective supplementation. Always check supplement labels, as many contain B6, to avoid accidental overconsumption. Informed and cautious use is key to preventing supplement-induced neuropathy.

For more information on vitamin toxicity and safety, consult resources from health organizations. For example, the Therapeutic Goods Administration (TGA) in Australia has issued warnings regarding high-dose B6 and peripheral neuropathy.

Frequently Asked Questions

Excessive intake of vitamin B6 (pyridoxine) is the primary B vitamin known to cause peripheral neuropathy. While B12 deficiency can cause neuropathy, B12 excess does not have the same toxic effect.

Early symptoms often include numbness, tingling, and a burning sensation in the hands and feet. An unsteady gait, loss of coordination, and difficulty walking can also develop.

In some cases, the nerve damage from B6 toxicity can be permanent, though symptoms often improve after discontinuing the supplement. The prognosis depends on the severity and duration of the over-consumption.

Toxicity from B6 is extremely rare from dietary sources alone. Neuropathy is caused by high-dose supplementation, not by consuming B6-rich foods like meat, fish, and legumes.

Always check the labels of all supplements you are taking, as many products contain B6. Avoid taking multiple supplements containing B vitamins simultaneously. Consult a healthcare professional before starting any B vitamin regimen.

High intake of folic acid from supplements can mask the symptoms of a vitamin B12 deficiency. This can delay the diagnosis of B12-related neuropathy, allowing the nerve damage to progress.

B complex supplements contain multiple B vitamins. While generally safe, it's important to be aware of the amount of vitamin B6 in these supplements, as excessive intake over time can lead to neuropathy. Always consult with a healthcare professional before taking supplements, especially if you have underlying health conditions or are taking other medications.