Vitamin B6
Also known as: pyridoxine, pyridoxal, pyridoxamine, pyridoxal-5-phosphate, PLP, P5P
Effective Dosage
1.4–80 mg/day depending on indication (no single established dose from provided studies)
What the Science Says
Vitamin B6 is an essential water-soluble vitamin that the body uses to make neurotransmitters like serotonin and dopamine, and to support dozens of enzyme reactions. Research in the provided studies suggests that low B6 intake is associated with higher anxiety and depression scores in people with type 2 diabetes, and that higher blood levels of its active form (PLP) may help pregnant women recover faster from nausea and vomiting. One small clinical trial also tested high-dose B6 (80 mg/day) as an add-on treatment for acute mania in bipolar disorder, though it did not outperform folate alone.
What It Doesn't Do
Won't boost male fertility — a large RCT found an antioxidant blend containing B6 did not improve pregnancy rates and may have slightly reduced them. Adding B6 on top of folate did not improve mania outcomes beyond folate alone. No evidence from these studies that B6 supplements directly treat depression or anxiety as a standalone therapy. Not a substitute for a balanced diet.
Evidence-Based Benefits
Vitamin B6 is essential for various bodily functions, including amino acid metabolism, neurotransmitter synthesis, and the production of hemoglobin. It has been shown to support cognitive function and may help alleviate symptoms of depression and anxiety in some individuals.
Strong EvidenceEffective at: 1.3-2.0 mg daily
Source: auto-research
Absorption & Bioavailability
Good — the active form PLP is measurable in blood and serum levels correlate with dietary intake and symptom outcomes in the provided studies. However, bioavailability from fortified plant-based foods was not always reflected in circulating levels for all nutrients.
Red Flags to Watch For
- High-dose B6 (above 100 mg/day long-term) is associated with peripheral neuropathy — none of the provided studies assessed this risk, so caution is warranted at doses like the 80 mg/day used in the bipolar trial
- B6 is often bundled in multi-ingredient supplements (e.g., antioxidant blends), making it impossible to isolate its specific effect — the SUMMER fertility trial found the whole blend was ineffective or potentially harmful
- Observational associations between low B6 intake and mood disorders do not prove that supplementing B6 will improve mood in healthy people
- Enzyme PNPO (which metabolizes B6) is implicated in cancer progression in lab research — the clinical significance for supplement users is unknown but warrants monitoring in future research
Products Containing Vitamin B6
See how Vitamin B6 is used in these analyzed products:
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: 2026-04-06