What is considered an elevated B6 level?

December 24, 2025 •

4 min read

While excessive consumption of vitamin B6 from food is unlikely to cause harm, consistently taking high doses from supplements is the most common cause of toxicity. This can lead to a condition called hypervitaminosis B6, which is primarily characterized by neurological problems like peripheral neuropathy.

Quick Summary

Elevated vitamin B6 levels, or hypervitaminosis B6, typically result from excessive supplement intake and can cause nerve damage, known as peripheral neuropathy. Symptoms include numbness, tingling, and poor coordination. While the normal range varies slightly, levels significantly above the Tolerable Upper Intake Level, or UL, of 100 mg/day for adults indicate potential toxicity. Stopping supplementation is the primary treatment.

Key Points

Definition: An elevated B6 level, or hypervitaminosis B6, results from excessive supplement intake, not food, leading to a buildup that can cause toxicity.
Toxicity Threshold: While the adult UL is 100 mg/day, adverse effects like nerve damage can sometimes occur at lower, chronic doses, such as 50 mg/day or less.
Main Symptom: The most common symptom is peripheral neuropathy, which causes numbness, tingling, and nerve pain, particularly in the hands and feet.
Common Culprits: Excessive supplementation, often from high-dose B-complex or individual B6 supplements, and energy drinks are the primary causes.
Management: The main treatment is to immediately stop all supplements containing B6. Recovery is often gradual, and some nerve damage can be permanent.
Blood Test: A blood test measuring pyridoxal 5'-phosphate (PLP) is used to determine B6 status, with normal levels typically between 20-125 nmol/L.

Understanding Healthy and Elevated B6 Levels

Vitamin B6, also known as pyridoxine, is an essential water-soluble vitamin that plays a crucial role in numerous bodily functions, including metabolism, red blood cell formation, and neurotransmitter synthesis. The recommended dietary allowance (RDA) for adults is between 1.3 and 1.7 mg per day, with needs slightly higher for pregnant and lactating women. A Tolerable Upper Intake Level (UL) has been established to protect against potential toxic effects from excessive intake. For adults, the UL is 100 mg/day.

Blood tests, typically measuring the active form of the vitamin called pyridoxal 5'-phosphate (PLP), are used to assess B6 status. While adequate PLP status is generally indicated by levels above 30 nmol/L, thresholds for toxicity are much higher and can vary. Levels considered elevated often exceed 100-200 nmol/L, though adverse effects like neuropathy can sometimes be seen with lower doses over long periods.

Causes of Elevated B6 Levels

Elevated B6 levels are almost exclusively the result of taking dietary supplements in high doses over an extended period. Unlike fat-soluble vitamins that are stored in the body's fat tissues, water-soluble vitamins like B6 are typically excreted in the urine when in excess. However, at high doses from supplements, the body's ability to excrete the vitamin is overwhelmed, leading to a buildup that can cause toxicity.

Here are the most common causes of hypervitaminosis B6:

Excessive Supplementation: This is the most frequent culprit. Many B-complex and multivitamin supplements contain amounts of B6 that are well above the RDA, and some single-ingredient supplements can have extremely high doses.
Long-Term Intake of Moderate Doses: Research indicates that even seemingly moderate doses (e.g., 50 mg/day) taken for an extended duration can cause problems in some individuals. Susceptibility to toxicity can vary from person to person.
Energy Drinks: Certain energy drinks contain high amounts of B6, which can contribute to excessive daily intake, especially when combined with other supplements or a vitamin-fortified diet.
Medical Conditions (Rare): A few specific, rare genetic conditions like hypophosphatasia (HPP) can cause the accumulation of PLP, leading to elevated B6 levels without supplementation. Patients on long-term dialysis may also have elevated B6 due to regular supplementation protocols.

Symptoms of High B6 Levels

The primary concern with high B6 levels is the risk of peripheral neuropathy, a type of nerve damage. The symptoms often develop gradually and may worsen over time with continued high intake. Key symptoms include:

Numbness and tingling: A "pins and needles" or burning sensation, most commonly affecting the hands and feet. This is often described as a "stocking-glove" sensation.
Lack of coordination (ataxia): Difficulty with balance and controlled movements, which can make walking challenging.
Sensory loss: A reduced ability to sense pain, temperature, or touch.
Muscle weakness: A decrease in muscle strength, particularly in the extremities.
Other symptoms: High B6 can also cause skin lesions, photosensitivity (sensitivity to sunlight), heartburn, and nausea.

In some cases, the symptoms of B6 toxicity can be misinterpreted, as they can mimic other conditions. This is why it's essential to inform your doctor of all supplements you are taking if you experience any of these symptoms.

Management and Recovery from Elevated B6

Fortunately, for most people, managing elevated B6 levels and recovering from toxicity is a straightforward process. The most critical step is to stop taking all supplements containing B6.

Since B6 is water-soluble, the body will naturally begin to excrete the excess vitamin once supplementation ceases. For the majority of cases, symptoms will gradually improve over time. However, recovery can be slow, sometimes taking several months or longer, and for severe nerve damage, some symptoms may be permanent.

Supportive care may also be part of the treatment plan, which can include:

Medication: Over-the-counter or prescription pain relievers to help manage nerve-related pain.
Physical Therapy: To help improve muscle strength, coordination, and balance.
Occupational Therapy: To assist with adapting to any persistent limitations caused by nerve damage.

Comparison of Healthy vs. Excessive B6 Intake


Feature	Healthy B6 Intake	Excessive B6 Intake
Source	Balanced diet (fish, poultry, potatoes, bananas)	High-dose supplements, energy drinks
Daily Dosage	1.3-1.7 mg (RDA for adults)	Can be 50-100+ mg, often unknowingly
Blood Test (PLP)	Normal range typically 20-125 nmol/L	Elevated, often exceeding 100-200 nmol/L
Toxicity Risk	Minimal to none, even with high-B6 foods	High risk of nerve damage over time
Nervous System	Supports brain function and nerve health	Causes peripheral neuropathy, ataxia
Symptom Onset	No adverse symptoms related to excess	Gradual onset of numbness, tingling, weakness

Conclusion

What is considered an elevated B6 level is often defined by blood test results indicating levels significantly above the typical range, especially when accompanied by symptoms of toxicity. Since toxicity is nearly always caused by over-supplementation rather than dietary sources, a crucial first step for anyone experiencing neuropathy symptoms is to review their supplement intake with a healthcare professional. Early detection and cessation of supplements can often lead to a slow but steady recovery. The key to maintaining a healthy B6 level is a balanced diet, with supplements only used under medical supervision, and with careful attention to dosage. For more information on vitamin levels and nutritional health, you may visit the National Institutes of Health Office of Dietary Supplements website.

Frequently Asked Questions

Levels of pyridoxal 5'-phosphate (PLP), the active form of B6, significantly higher than the normal range (20-125 nmol/L) can be dangerous. Some studies suggest toxic effects can occur at levels above 100 nmol/L, though symptoms can vary based on individual sensitivity and duration of exposure.

The Tolerable Upper Intake Level (UL) for B6 in adults is 100 mg per day. Consistent intake above this level, especially from supplements, significantly increases the risk of developing toxicity and nerve damage.

The first signs of B6 toxicity typically involve the nervous system and can include numbness, tingling, and a burning sensation, most often starting in the hands and feet. These symptoms of peripheral neuropathy can progress to other issues like poor coordination.

The fastest and most effective way to lower elevated B6 levels is to immediately stop taking all supplements containing B6. Because it is water-soluble, the body will begin to excrete the excess vitamin.

While the primary symptoms of B6 toxicity are neurological (peripheral neuropathy), some anecdotal reports and preliminary studies have suggested that high doses of B6 may be linked to mood changes, including anxiety, but this is less common than neuropathy.

After stopping supplements, B6 levels can take anywhere from a few weeks to several months to return to a normal range. The duration of recovery for symptoms depends on the severity and duration of the excess, with some nerve damage potentially being irreversible.

No, consuming a normal diet rich in B6-containing foods, such as fish, poultry, and vegetables, does not cause elevated levels. The body is able to effectively regulate absorption and excretion of B6 from natural dietary sources.