HypeCheck

Last verified: 8 days ago

Vitamin B6

Also known as: pyridoxine, pyridoxal, pyridoxamine, pyridoxal-5-phosphate, PLP, P5P

Evidence under review. — Not yet rated

Essential B vitamin supporting mood, nerve health, and metabolism. First-line for pregnancy nausea.

  • What it does

    Vitamin B6 is a water-soluble vitamin that acts as a coenzyme in over 100 enzymatic reactions, including the production of neurotransmitters like serotonin, GABA, and dopamine. Clinical evidence...

  • Evidence quality

    Evidence base hasn't been formally rated yet. See research below.

  • Clinical dose

    8-100 mg daily depending on condition; do not exceed 21 mg/day long-term without medical supervision

What the Science Says

Vitamin B6 is a water-soluble vitamin that acts as a coenzyme in over 100 enzymatic reactions, including the production of neurotransmitters like serotonin, GABA, and dopamine. Clinical evidence supports its use as a first-line treatment for mild-to-moderate nausea and vomiting in pregnancy, and a double-blind RCT found that 100 mg/day reduced depression symptoms in people with mild-to-moderate depression at baseline. It also plays a key role in amino acid metabolism, and deficiency is common in hemodialysis patients and those on certain medications like carbidopa/levodopa.

What It Doesn't Do

Won't cure depression on its own — the evidence is from a single RCT in mostly women and needs replication. Not proven to boost athletic performance. No solid evidence it directly treats carpal tunnel syndrome when used in combination supplements. Doesn't reliably lower homocysteine better than betaine in metabolic patients. Not a standalone treatment for liver disease.

Evidence-Based Benefits

Reduces nausea and vomiting in early pregnancy and is recommended as a first-line treatment.

Moderate Evidence

Effective at: No established dose from provided studies

Supporting studies (click to view on PubMed):

100 mg/day reduced depression symptoms in adults with mild-to-moderate depression in a double-blind RCT.

Moderate Evidence

Effective at: 100 mg/day

Supporting studies (click to view on PubMed):

Deficiency is common in hemodialysis patients and routine low-dose supplementation may be warranted.

Weak Evidence

Effective at: No established dose from provided studies

Supporting studies (click to view on PubMed):

Higher dietary B6 intake is associated with lower risk of liver-related events in people with fatty liver disease.

Weak Evidence

Effective at: No established dose from provided studies

Supporting studies (click to view on PubMed):

Acts as a coenzyme in serotonin, GABA, and dopamine synthesis, supporting mood and nervous system function.

Moderate Evidence

Effective at: No established dose from provided studies

Supporting studies (click to view on PubMed):

Absorption & Bioavailability

Good — pyridoxine is well absorbed orally; pyridoxal-5-phosphate (PLP) is the active form in blood. High-flux hemodialysis dialyzers can significantly deplete B6 regardless of dietary intake, suggesting dialysis-related losses override normal absorption.

Red Flags to Watch For

  • Chronic intake above 21 mg/day may increase risk of peripheral neuropathy (nerve toxicity), especially in athletes using multiple fortified supplements or sports drinks
  • Dangerous interaction identified with valproic acid (a common epilepsy drug) — co-exposure caused cardiac toxicity in zebrafish models; consult a doctor before combining
  • Carbidopa/levodopa (Parkinson's medication) may deplete vitamin B6, potentially causing neuropathy, seizures, or anemia — monitoring is advised
  • High-dose B6 supplements (100 mg+) should not be taken long-term without medical supervision; toxicity risk is real and underappreciated
  • Hemodialysis patients are at high risk of deficiency (63% in one study) even on presumed adequate diets — routine testing is warranted

Products Containing Vitamin B6

See how Vitamin B6 is used in these analyzed products:

Frequently Asked Questions

What does Vitamin B6 do?

Essential B vitamin supporting mood, nerve health, and metabolism. First-line for pregnancy nausea.

What is the effective dose of Vitamin B6?

8-100 mg daily depending on condition; do not exceed 21 mg/day long-term without medical supervision

Is Vitamin B6 safe?

Chronic intake above 21 mg/day may increase risk of peripheral neuropathy (nerve toxicity), especially in athletes using multiple fortified supplements or sports drinks

What doesn't Vitamin B6 do?

Won't cure depression on its own — the evidence is from a single RCT in mostly women and needs replication.

Research Sources

  • PubMed
  • NIH DSLD

This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-09-16