The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Patients should avoid vitamin B6 products if they are sensitive or allergic to any of their ingredients.
Side Effects and Warnings
Some individuals seem to be particularly sensitive to vitamin B6 and may have problems at lower doses. Overall, pyridoxine is generally considered safe in adults and children when used appropriately at recommended doses.
Arrhythmia (abnormal heart rhythm), skin reactions (such as acne, allergic reactions, and photosensitivity), gastrointestinal effects (such as nausea, vomiting, abdominal pain, loss of appetite, a feeling of a lump in the throat, abdominal discomfort, heartburn, recurrence of ulcerative colitis (in patients with ulcerative colitis)), increased liver function test results (serum aspartate transaminase (AST, SGOT)), neurologic effects (such as headache, paresthesia (an abnormal physical sensation such as prickling, tingling or numbness), somnolence, sedation, and sensory neuropathy), breast soreness or enlargement, persistent bleeding, decreased serum folic acid levels, seizures after large doses, hypotonia (decreased muscle tone or strength), and respiratory distress in infants have been reported.
Adverse reactions to preservatives in high-dose pyridoxine hydrochloride intravenous injections are possible
Vitamin B6 may lower blood pressure. Caution is advised in patients taking agents that lower blood pressure.
Vitamin B6 may affect blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Vitamin B6 may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
Use cautiously in patients with cardiovascular or gastrointestinal conditions.
Use cautiously in patients taking agents for Parkinson's disease, as pyridoxine enhances the metabolism of levodopa, reducing its antiparkinsonism effects. However, the use of carbidopa and levodopa (Sinemet®) may avoid this interaction, as carbidopa can reduce pyridoxine levels.
Avoid if allergic or hypersensitive to any ingredient in vitamin B6 products.
Avoid excessive dosing (doses higher than 200 milligrams daily).
Avoid high doses during pregnancy or lactation. A special sustained-release multi-ingredient product has been approved by the U.S. Food and Drug Administration (FDA) for use in pregnancy. However, it should not be used long-term, without medical supervision and close monitoring, or in more excessive doses. There is some concern that high-dose maternal pyridoxine can cause neonatal seizures.
Pregnancy and Breastfeeding
Vitamin B6 is likely safe during pregnancy when used orally in doses not exceeding the recommended dietary allowance (RDA). Vitamin B6 is possibly safe when used orally and appropriately in amounts exceeding the recommended dietary allowance. A special sustained-release multi-ingredient product has been approved by the U.S. Food and Drug Administration (FDA) for use in pregnancy. However, it should not be used long-term, without medical supervision and close monitoring, or in more excessive doses. There is some concern that high-dose maternal pyridoxine can cause neonatal seizures.
Vitamin B6 is likely safe during lactation when used orally in doses not exceeding the RDA. There is insufficient reliable information about the safety of pyridoxine when used in higher doses in lactating women. Because most breastfeeding women do not consume the RDA of vitamin B6 in their normal diets and do not provide totally breastfed infants with the RDA of this vitamin, higher doses of vitamin B6 may be recommended, although benefits have not been well proven.