Understanding Vitamin B6: Normal vs Optimal Ranges

?What is Vitamin B6?

Vitamin B6 (pyridoxine) is a water-soluble B vitamin involved in over 100 enzymatic reactions, including amino acid metabolism, neurotransmitter synthesis (serotonin, dopamine, GABA), haemoglobin production, and homocysteine metabolism. The active form measured in labs is pyridoxal-5-phosphate (PLP).

!Why It Matters

B6 deficiency causes peripheral neuropathy, dermatitis, glossitis, depression, and immune dysfunction. Along with B12 and folate, B6 is one of the three key B vitamins that regulate homocysteine. Adequate B6 also supports serotonin and dopamine production, making it important for mood regulation.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Peripheral neuropathy (tingling, burning in extremities)
• Depression, irritability, confusion
• Dermatitis, seborrhoeic rash
• Glossitis (sore tongue)

How to Improve Your Levels

• 1Dietary sources: poultry, fish, bananas, potatoes, chickpeas, and fortified cereals
• 2Supplement 25–100 mg/day for deficiency — do not exceed 100 mg long-term, as high doses cause sensory neuropathy
• 3Limit alcohol, which depletes B6 and impairs its activation
• 4Review medications (e.g., isoniazid) that interfere with B6 metabolism
• 5Use the active form (pyridoxal-5-phosphate) if conversion is impaired

When to Test

Not routinely tested. Consider when investigating peripheral neuropathy, elevated homocysteine despite B12/folate supplementation, or suspected nutritional deficiency.

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