Vitamin B6 (Pyridoxine / P-5-P)

Summary

Vitamin B6 plays a central role in the synthesis of neurotransmitters (dopamine, serotonin, GABA)
and supports steroid conversion and cellular energy production.
Not a direct hormonal “booster,” but an essential metabolic cofactor for proper endocrine and nervous system balance.

🟢 What It Does (Main Evidence)

• Supports the production of dopamine and serotonin, possibly improving mood and energy when deficient.
• Involved in steroid and testosterone metabolism via B6-dependent enzymes.
• May reduce premenstrual symptoms (PMS) at physiological doses (moderate evidence).
• Essential for amino acid metabolism and immune function.

🟡 What’s Unclear (Gray Areas)

• “Hormone-boosting” effects are unproven in non-deficient individuals.
• The efficacy of P-5-P vs pyridoxine varies across studies.
• Limited data on direct impact on fatigue or cognitive performance.

🔴 What It Doesn’t Do

• Does not significantly increase testosterone or muscle mass.
• Does not replace a diet rich in B6 (meat, fish, legumes, bananas).
• Does not prevent neurological disorders without a true deficiency.

Intake & Dosage (Non-prescriptive)

• Recommended intake (adults): ≈ 1.3–1.7 mg/day.
• Light supplementation: 1.3–5 mg/day, or P-5-P in small doses if specific needs.
• Avoid megadoses (>50–100 mg/day) long-term without medical advice.

💣 Upper Limit (UL)

Note: The upper limit is $100 mg/day ($NIH / EFSA / Health Canada).
Exceeding this threshold provides no proven benefit — only an increased risk of neuropathy.

Safety

• Well tolerated at physiological doses.
• Chronic high doses can cause peripheral neuropathy (tingling, numbness, loss of sensation).
• Effects are usually reversible upon discontinuation.

Risks & Interactions

• Very high chronic doses → risk of sensory neuropathy (tingling, numbness).
• Rare cases of nausea or slow digestion.
• Can interact with certain **antiepileptics** or **isoniazid** (depletion of B6).
• Prefer moderate doses; **P-5-P** form useful for sensitivity or absorption issues.

Quality Tips

• Prefer low-dose forms (1–5 mg) of P-5-P or pyridoxine HCl.
• Avoid high-strength products (>50 mg) unless prescribed.
• Choose brands with transparent sourcing and COA certificates.

Sources

• ODS/NIH — Vitamin B6 Fact Sheet
• EFSA / Health Canada — B6 reference intakes & UL