Studies of pregnancy nausea used pyridoxine 10–25 mg three to four times daily short term under obstetric care
Reviewed · Published
Vitamin B6
Supports amino-acid metabolism, neurotransmitter synthesis, and hemoglobin formation.
Established functions
- Supports amino-acid metabolism, neurotransmitter synthesis, and hemoglobin formation.
Dietary sources
- tuna
- chicken
- potatoes
Claims and evidence
Claims that Vitamin B6 alone prevents or treats disease, or invariably improves health without deficiency, are unsupported.
Japanese reference amounts
- Japanese adults (age and sex as specified): Adult men 1.4 mg/day; women 1.1 mg/day (RDA)
Amounts studied
- Studies of pregnancy nausea used pyridoxine 10–25 mg three to four times daily short term under obstetric care
Tolerable upper limits
- Adults: 40–60 mg/day as pyridoxine, varying by age and sex
Forms and bioavailability
Supplement forms: pyridoxine hydrochloride, pyridoxal 5-phosphate
- Both forms are utilized at usual doses; clinical superiority of P-5-P is unproven.
Safety and interactions
Adverse effects
- sensory neuropathy with chronic high doses
- photosensitivity
- nausea
Medicine and nutrient interactions
- levodopa without carbidopa, phenytoin, phenobarbital
Contraindications and cautions
- People with unexplained neuropathy should stop and seek assessment.
Practical selection
- Compare Vitamin B6 amount per serving, form, allergens, and batch testing; prefer a single-ingredient product suited to the intended use.
Sources and review
- Dietary Reference Intakes for Japanese (2025)Ministry of Health, Labour and Welfare (Japan)
- NIH ODS vitamin fact sheetsNIH Office of Dietary Supplements
Daiki Minaki (editorial and evidence review) ·