What Is Pyridoxine and How Does It Work?

Pyridoxine is a vitamin used for preventing and treating low levels of pyridoxine (pyridoxine deficiency) and the "tired blood" (anemia) that may result. It is also used for heart disease; high cholesterol; reducing blood levels of homocysteine, a chemical that might be linked to heart disease; and helping clogged arteries stay open after a balloon procedure to unblock them (angioplasty).

  • Pyridoxine is available under the following different brand names: vitamin B6, and Nestrex.

What Are Dosages of Pyridoxine?

Dosages of Pyridoxine:

Dosage Forms and Strengths


  • 10 mg
  • 25 mg
  • 50 mg
  • 100 mg
  • 200 mg
  • 250 mg
  • 500 mg

Tablets, extended-release

  • 200 mg

Dosage Considerations – Should be Given as Follows:

Recommended Daily Allowance (RDA)


  • Younger than 50 years old: 1.3 mg/day
  • Older than 50 years old: 1.7 mg/day


  • Younger than 50 years old: 1.3 mg/day
  • Older than 50 years old: 1.5 mg/day
  • Pregnant: 1.9 mg/day; Nursing: 2 mg/day


  • Up to 6 months old: 0.1 mg/ day
  • Children 6-12 months old: 0.3 mg/ day
  • Children 1-3 years old: 0.5 mg/ day
  • Children 4-8 years old: 0.6 mg/ day
  • Children 9-13 years old: 1 mg/ day
  • Children 14-18 years old (male) 1.3 mg/day; (female) 1.2 mg/day
  • Upper Limit (UL): 1-3 years old: 30 mg/day; 4-8 years old: 40 mg/day; 9-13 years old: 60 mg/day; 14-18 years old: 80 mg/day

Pyridoxine Deficiency

  • 10-100 mg intravenously/intramuscularly (IV/IM)
  • 2.5-10 mg/day orally

Pyridoxine-Responsive Seizures, Pediatric

  • 10-100 mg intravenously/intramuscularly (IV/IM)

Nausea in Pregnancy

  • 75 mg orally once/day

Other Indications and Uses

  • Morning sickness, sideroblastic anemia
  • See also pyridoxine AD

What Are Side Effects Associated with Using Pyridoxine?

Common side effects of pyridoxine include:

  • Decreased folic acid
  • Decreased sensation
  • Headache
  • Loss of appetite
  • Nausea
  • Numbness and tingling
  • Sensory nerve damage
  • Sleepiness
  • Stomach pain
  • Unstable gait
  • Vomiting

This is not a complete list of side effects and other serious side effects may occur. Call your doctor for information and medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Pyridoxine?

If your doctor has directed you to use this medication for your condition, your doctor or pharmacist may already be aware of any possible drug interactions or side effects and may be monitoring you for them. Do not start, stop, or change the dosage of this medicine or any medicine before getting further information from your doctor, healthcare provider, or pharmacist first.

  • Pyridoxine has no known severe or serious interactions with other drugs.
  • Moderate Interactions of pyridoxine include:
  • Pyridoxine has mild interactions with at least 71 different drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Pyridoxine?


  • This medication contains pyridoxine. Do not take vitamin B6 or Nestrex if you are allergic to pyridoxine or any ingredients contained in this drug.
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Hypersensitivity

Effects of Drug Abuse

  • Longer use can cause the bowels to stop functioning normally and might cause dependence on laxatives.
  • Long-term use can cause changes in blood electrolytes that can cause heart function disorders, muscle weakness, liver damage, and other harmful effects.

Short-Term Effects

  • See "What Are Side Effects Associated with Using Pyridoxine?"

Long-Term Effects

  • Long-term large doses may induce nerve damage (neuropathy).
  • See "What Are Side Effects Associated with Using Pyridoxine?"


  • Long-term large doses may induce nerve damage (neuropathy).
  • Do not give intravenously (IV) to heart disease patients.

Pregnancy and Lactation

  • Pyridoxine is generally acceptable for use during pregnancy when doses are within the recommended daily allowance (RDA). Controlled studies in pregnant women show no evidence of fetal risk. Use with pyridoxine caution during pregnancy in doses exceeding the recommended daily allowance (RDA) if benefits outweigh risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
  • Pyridoxine is considered safe for use while breastfeeding.
Medscape. Pyridoxine.
RxList. Pyridoxine Supplements

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