✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full Pyridoxine evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Peripheral neuropathy in a patient taking B6 supplements — check dose and duration; toxicity occurs at >200 mg/day (sometimes lower) [4]
⚠ Patient starting isoniazid without B6 co-prescription — up to 50% will develop neuropathy without it [3]
⚠ Microcytic anemia with ringed sideroblasts on marrow — pyridoxine-responsive sideroblastic anemia [3]
⚠ Levodopa monotherapy patient taking B6 — accelerates peripheral decarboxylation (NOT an issue with carbidopa-levodopa) [3]
⚠ Refractory neonatal seizures — empiric IV pyridoxine 100 mg for pyridoxine-dependent epilepsy [3]
🥗 Food first — build your daily 1.3 mg; 1.7 mg if >50y
Check the foods you regularly eat — the bar fills toward your daily target.
Chickpeas, canned (170 g)1.14 mg
Beef liver, cooked (85 g)0.9 mg
Tuna, yellowfin (85 g)0.88 mg
Salmon, cooked (85 g)0.64 mg
Chicken breast, cooked (85 g)0.51 mg
Potato, baked (1 medium)0.44 mg
Banana (1 medium)0.43 mg
Fortified cereal (30 g)0.5 mg
Check your regular foods above
☑ Risk checker
Isoniazid, cycloserine, or penicillamine therapy [3]
Chronic alcoholism (acetaldehyde displaces PLP from proteins) [3]
Autoimmune conditions (RA, IBD — increased catabolism) [2]
Chronic kidney disease on hemodialysis (dialysis losses) [2]
Elderly with poor dietary diversity [2]
Malabsorptive conditions (celiac disease) [2]
Select factors
🔬 Lab interpreter
Recommended test
Plasma pyridoxal 5'-phosphate (PLP)
Plasma pyridoxal 5'-phosphate (PLP)
Reference range / target
>30 nmol/L (adequate); <20 nmol/L (deficient)
>30 nmol/L (adequate); <20 nmol/L (deficient)
The most commonly used and reliable biomarker. Reflects tissue B6 status. Affected by inflammation (PLP is an acute-phase reactant — falls during inflammation) [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: Specific dosage data under clinical review
👦 Pediatric: See guidance
Infants 0–6 months: 0.1 mg/day AI; children 1–3 years: 0.5 mg/day; 4–8 years: 0.6 mg/day [1]. Pyridoxine-dependent epilepsy is a rare but treatable cause of neonatal seizures — empiric pyridox
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Specific dosage data under clinical review
🌱 Vegan: Standard dose
How to take
🍽 Timing: Can be taken at any time of day, with or without food [1].
💊 With food: No specific requirement. Water-soluble vitamin [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Pyridoxine HCl', 'common', 'Most common supplemental form. Must be converted to PLP via pyridoxal kinase and PNP oxidase (requires riboflavin as FMN). Inexpensive and widely available [1].'] | Standard | Check label | |
| ["Pyridoxal 5'-phosphate (P5P, PLP)", 'preferred', 'The bioactive coenzyme form. Bypasses hepatic conversion. May be beneficial for individuals with impaired conversion. More expensive [2].'] | Standard | Check label | |
| ['Pyridoxamine', '', 'Found naturally in animal foods. Converted to PLP in the body. Investigated for anti-glycation properties in diabetes [1].'] | Standard | Check label |
3 Common questions
Can too much B6 cause nerve damage? ▼
Yes — this is the most important safety concern. Chronic intake above 200 mg/day (and in some cases 50 mg/day for prolonged periods) causes sensory peripheral neuropathy: numbness, tingling, loss of coordination [4]. This is dose- and duration-dependent and usually reversible upon discontinuation, but may take months. The UL is 100 mg/day [1].
Why is B6 prescribed with isoniazid? ▼
Isoniazid forms hydrazone complexes with pyridoxal 5'-phosphate, functionally depleting the active coenzyme. Without co-prescription of B6 (25–50 mg/day), up to 50% of patients on isoniazid develop peripheral neuropathy [3]. This is standard of care in tuberculosis treatment.
Does B6 help with morning sickness? ▼
Yes — pyridoxine 10–25 mg three times daily is the ACOG first-line treatment for nausea and vomiting of pregnancy. The combination of pyridoxine + doxylamine (Diclegis) is FDA-approved for NVP [6]. It is safe and moderately effective.
Is the P5P form better than pyridoxine HCl? ▼
P5P (pyridoxal 5'-phosphate) is the bioactive coenzyme form and bypasses hepatic conversion. It may be beneficial for individuals with impaired conversion (liver disease, genetic variants). However, for most people, standard pyridoxine HCl is effective and much less expensive [2].
4 Clinical evidence
Strong
Prevention of isoniazid-induced peripheral neuropathy: 25–50 mg/day co-prescribed with isoniazid is standard of care [3]. Treatment of pyridoxine-dependent epilepsy in neonates (genetic PLP deficiency) [3]. Essential role in heme synthesis — deficiency causes sideroblastic (microcytic) anemia [2]. HIGH
Moderate
Nausea and vomiting of pregnancy (NVP): 10–25 mg three times daily is first-line pharmacotherapy (often combined with doxylamine as Diclegis/Diclectin) [6]. Premenstrual syndrome: doses of 50–100 mg/day may improve mood and somatic symptoms in some women [2]. Homocysteine reduction: B6 supplementation (with folate and B12) reduces plasma homocysteine [7]. MODERATE
Insufficient
Cardiovascular disease prevention through homocysteine lowering — trials have not shown consistent cardiovascular event reduction [7]. Carpal tunnel syndrome treatment: frequently marketed but evidence is weak [2]. Cognitive decline prevention: observational associations but no convincing RCT evidence [2]. ADHD or autism symptom management [2]. LOW
5 Safety, toxicity & adverse events
Relative
⚠ High-dose chronic use (>200 mg/day long-term) — causes dose-dependent sensory peripheral neuropathy
⚠ Levodopa without carbidopa — B6 accelerates peripheral levodopa breakdown, reducing efficacy
⚠ Phenytoin and phenobarbital — B6 can lower drug levels
🚩 Red flags
● Patient on high-dose B6 (>50 mg/day) with new numbness or tingling — suspect pyridoxine toxicity [4]
● Isoniazid patient without B6 co-prescription — neuropathy risk up to 50% [3]
● Microcytic anemia not responding to iron therapy — consider sideroblastic anemia from B6 deficiency [3]
● Levodopa monotherapy patient with worsening Parkinson symptoms after starting B6 — drug interaction [3]
● Refractory neonatal seizures — give empiric IV pyridoxine 100 mg [3]
6 Interactions
Drug interactions
Levodopa (monotherapy) Major
Mechanism: B6 enhances peripheral aromatic L-amino acid decarboxylase activity, accelerating conversion of levodopa to dopamine outside the CNS. Less levodopa reaches the brain. [3]
Effect: Reduced efficacy of levodopa. Worsening Parkinson symptoms. [3]
Action: Contraindicated with levodopa monotherapy. NOT an issue with carbidopa-levodopa (Sinemet) — carbidopa blocks peripheral decarboxylase [3].
Isoniazid Major
Mechanism: Isoniazid forms hydrazone complexes with PLP, functionally depleting the active coenzyme. Also inhibits pyridoxal kinase. [3]
Effect: Peripheral neuropathy in up to 50% of patients without B6 co-prescription. [3]
Action: Always co-prescribe pyridoxine 25–50 mg/day with isoniazid. This is standard of care [3].
Cycloserine Moderate
Mechanism: Inhibits PLP-dependent enzymes, causing functional B6 deficiency. [3]
Effect: CNS toxicity: seizures, psychosis, peripheral neuropathy. [3]
Action: Co-prescribe pyridoxine 50–200 mg/day to prevent neuropsychiatric side effects [3].
Phenytoin and phenobarbital Moderate
Mechanism: High-dose B6 (>200 mg/day) may increase hepatic metabolism of anticonvulsants. [2]
Effect: Potentially reduced anticonvulsant levels. [2]
Action: Monitor anticonvulsant levels if B6 supplementation exceeds RDA [2].
Supplement synergies
Folate and B12 · Standard RDA of each
The B6-B9-B12 triad works together in homocysteine metabolism. B6 (as PLP) is the cofactor for cystathionine beta-synthase, the alternative pathway for homocysteine disposal [7].
The B6-B9-B12 triad works together in homocysteine metabolism. B6 (as PLP) is the cofactor for cystathionine beta-synthase, the alternative pathway for homocysteine disposal [7].
Magnesium · 320–420 mg/day magnesium
B6 enhances intracellular magnesium accumulation. Commonly co-supplemented (Magne-B6 product widely used in Europe) [2].
B6 enhances intracellular magnesium accumulation. Commonly co-supplemented (Magne-B6 product widely used in Europe) [2].
Riboflavin (B2) · 1.1–1.3 mg/day
FMN (from riboflavin) is a cofactor for pyridoxine 5'-phosphate oxidase, which converts pyridoxine to active PLP [1].
FMN (from riboflavin) is a cofactor for pyridoxine 5'-phosphate oxidase, which converts pyridoxine to active PLP [1].
7 Regulatory
United States (FDA): Classified as a dietary supplement. UL: 100 mg/day for adults. No mandatory fortification but commonly added to enriched grains [1].
European Union (EFSA): Authorized health claims for energy metabolism, nervous system function, homocysteine metabolism, protein/glycogen metabolism, psychological function, red blood cell formation, immune function, and reduction of fatigue [8]. UL: 25 mg/day (EFSA, stricter than US).
Japan (MHLW): Eligible for Foods with Function Claims. Recommended intake: 1.4 mg/day for adult males. UL: 40–60 mg/day depending on age.
South Korea (MFDS): Registered health functional food ingredient. Approved claims: protein metabolism and immune function.
8 Cite this page
Vancouver: Pkhakadze G. Pyridoxine — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Aug 15]. Available from: https://supplement.ge/ingredients/pyridoxine/
APA 7th: Pkhakadze, G. (2026). Pyridoxine — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/pyridoxine/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: February 2027
References: 8 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Pyridoxine — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/pyridoxine/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG