From the Guidelines
Your vitamin B6 level of 102 mcg/L is elevated above the normal range, and you should discontinue any vitamin B6 supplements or multivitamins containing B6 that you may be taking to prevent potential nerve damage. According to the Institute of Medicine Food and Nutrition Board 1, the recommended dietary allowance (RDA) for vitamin B6 is 1.3 mg/day, and the tolerable upper intake level is 100 mg/day, beyond which sensory neuropathy may occur.
Key Considerations
- Elevated vitamin B6 levels can occur from excessive supplementation, certain medications, or some medical conditions 1.
- Significantly high levels can lead to nerve damage (peripheral neuropathy) with symptoms like numbness, tingling, or pain in hands and feet.
- You should consult with your healthcare provider to determine the cause of your elevated levels and for appropriate monitoring.
Next Steps
- Discontinue any vitamin B6 supplements or multivitamins containing B6.
- Consult with your healthcare provider for blood tests to track your levels as they return to normal.
- Your doctor may also want to evaluate for other potential causes if you're not taking supplements, as laboratory evaluation of micronutrient status can be confounded by methodological problems 1.
From the Research
Vitamin B6 Levels
- The normal range for vitamin B6 levels is not explicitly stated in the provided studies, but a level of 102 mcg/L is mentioned as being above the normal range of up to 64 mcg/L.
- According to 2, a plasma PLP concentration above 30 nmol/L (7.4 μg/L) is indicative of an adequate vitamin B6 status for all age and sex groups.
- The study 2 also suggests that PLP-based supplements should be administered weekly in low doses (50-100 mg) to maintain a stable serum PLP level between 30 and 60 nmol/L or 7.4 and 15 μg/L.
Toxicity and Neurotoxicity
- Vitamin B6 toxicity can occur at levels above 100 nmol/L or 25 μg/L, according to 2.
- The study 3 presents a case of vitamin B6 toxicity in a patient with a serum vitamin B6 level of 259.9 nmol/L, which is above the reference range of 20-125 nmol/L.
- The study 4 suggests that higher vitamin B6 levels may lead to the development of a predominantly sensory neuropathy of the axonal type.
- According to 5, moderately elevated plasma B6 levels, even in the 100 to 200 μg/L range, are not associated with significantly worse neuropathy signs or symptoms.
Supplementation and Daily Intake
- The currently recommended daily allowance of B6 is 1.5-2 mg/d from dietary sources, according to 2.
- The study 2 suggests that PLP-based supplements are preferred over pyridoxine supplements because of minimal neurotoxicity observed in neuronal cell viability tests.
- The European Food Safety Administration's (EFSA) newly established Tolerable Upper Intake Level (UL) of 12 mg/day is mentioned in 3 as a guideline for daily intake.