Vitamin B-6 (Pyridoxine)

Vitamin B6 is a type of B vitamin. It can be found in certain foods such as cereals, beans, vegetables, liver, meat, and eggs. It can also be made in a laboratory.

Vitamin B6 is 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 and blood vessel disease; high cholesterol and other fats in the blood; high blood pressure; stroke; 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).

Women use vitamin B6 for premenstrual syndrome (PMS) and other menstruation problems, "morning sickness" (nausea and vomiting) in early pregnancy, stopping breastmilk flow after childbirth, depression related to pregnancy, menopause, or using birth control pills, and symptoms of menopause.

Vitamin B6 is also used for Alzheimer's disease and other types of dementia or memory loss, attention deficit-hyperactivity disorder (ADHD), Down syndrome, autism, diabetes and related nerve pain, sickle cell anemia, migraine headaches, asthma, carpal tunnel syndrome, night leg cramps, muscle cramps, arthritis, preventing fractures in people with weak bones, allergies, acne and various other skin conditions, and infertility. It is also used for dizziness, motion sickness, preventing the eye disease age-related macular degeneration (AMD), seizures, convulsions due to fever, and movement disorders (tardive dyskinesia, hyperkinesis, chorea), as well as for increasing appetite and helping people remember dreams.

Some people use vitamin B6 for boosting the immune system, eye infections, bladder infections, tooth decay, and preventing polyps, cancer, and kidney stones.

Vitamin B6 is also used to overcome certain harmful side effects related to radiation treatment and treatment with medications such as mitomycin, procarbazine, cycloserine, fluorouracil, hydrazine, isoniazid, penicillamine, and vincristine.

Vitamin B6 is also used for nausea and vomiting associated with gastrointestinal illness in children and with use of birth control taken by mouth.

Vitamin B6 is frequently used in combination with other B vitamins in vitamin B complex products.

You may remember a prescription medication called Bendectin that was used for morning sickness in pregnancy. Bendectin contained vitamin B6 (pyridoxine) and a sleep-inducing antihistamine called doxylamine. The makers of Bendectin took it off the market in 1983 because they were running up expensive legal bills in defense of their product. Opponents charged it might be responsible for birth defects. Meanwhile, a product called Diclectin that is similar to Bendectin remained available in Canada, and there was research showing that neither vitamin B6 (pyridoxine) nor Bendectin seems to cause birth defects in animals. After Bendectin was removed from the market, there was no reduction in birth defects, but hospitalization rates for pregnancy-related nausea and vomiting doubled.

How does it work?

Vitamin B6 is required for the proper function of sugars, fats, and proteins in the body. It is also required for the proper growth and development of the brain, nerves, skin, and many other parts of the body.

Anemia (sideroblastic anemia).
Certain seizures in infants (pyridoxine-dependent seizures).
Vitamin B6 deficiency.
High homocysteine blood levels.
Age-related vision loss (macular degeneration).
Hardening of the arteries (atherosclerosis).
Kidney stones.
Upset stomach and vomiting in pregnancy.
Premenstrual syndrome (PMS).
Movement disorders (tardive dyskinesia).

Adults

By Mouth:

For hereditary sideroblastic anemia: Initially, 200-600 mg of vitamin B6 is used. The dose is decreased to 30-50 mg per day after an adequate response.

For vitamin B6 deficiency: In most adults, the typical dose is 2.5-25 mg daily for three weeks then 1.5-2.5 mg per day thereafter. In women taking birth control pills, the dose is 25-30 mg per day.

For abnormally high levels of homocysteine in the blood: For reducing high levels of homocysteine in the blood after childbirth, 50-200 mg of vitamin B6 has been taken alone. Also, 100 mg of vitamin B6 has been taken in combination with 0.5 mg of folic acid.

For preventing macular degeneration: 50 mg of vitamin B6 in the form of pyridoxine has been used daily in combination with 1000 mcg of vitamin B12 (cyanocobalamin) 1000 mcg and 2500 mcg of folic acid for about 7 years.

For hardening of the arteries (atherosclerosis): A specific supplement (Kyolic, Total Heart Health, Formula 108, Wakunga) containing 250 mg of aged garlic extract, 100 mcg of vitamin B12, 300 mcg of folic acid, 12.5 mg of vitamin B6, and 100 mg of L-arginine daily for 12 months.

For kidney stones: 25-500 mg of vitamin B6 has been used daily.

For nausea during pregnancy: 10-25 mg of vitamin B6 taken three or four times per day has been used. In people who don't respond to vitamin B6 alone, a combination product containing vitamin B6 and the drug doxylamine (Diclectin, Duchesnay Inc.) is used three or four times per day. Also, another product containing 75 mg of vitamin B6, 12 mcg of vitamin B12, 1 mg of folic acid, and 200 mg of calcium (PremesisRx, KV Pharmaceuticals) is used daily.

For symptoms of premenstrual syndrome (PMS): 50-100 mg of vitamin B6 is used daily, alone or along with 200 mg of magnesium.

For treating tardive dyskinesia: 100 mg of vitamin B6 per day has been increased weekly up to 400 mg per day, given in two divided doses.

Injected into Muscle:

Hereditary sideroblastic anemia: 250 mg of vitamin B6 daily, reduced to 250 mg of vitamin B6 weekly once adequate response is achieved.

Children

By Mouth:

For kidney stones: Up to 20 mg/kg daily in children aged 5 years and up.

Injected into Vein or Muscle:

For seizures that respond to vitamin B6 (pyridoxine-dependent seizures): 10-100 mg is recommended.

Vitamin B6 is SAFE for most people when used appropriately.

Vitamin B6 is SAFE when taken by mouth in amounts greater than the recommended dietary allowance. In some people, vitamin B6 might cause nausea, vomiting, stomach pain, loss of appetite, headache, tingling, sleepiness, and other side effects.

Long-term use of high doses of vitamin B6 and when vitamin B6 is given as a shot into the muscle is POSSIBLY UNSAFE. When used orally in high doses it might cause certain brain and nerve problems. When given as a shot into the muscle it might cause muscle problems.

Pregnancy and breast-feeding: Vitamin B6 is SAFE for pregnant women when taken under the supervision of their healthcare provider. It is sometimes used in pregnancy to control morning sickness. High doses are UNSAFE. High doses can cause newborns to have seizures.

Vitamin B6 is SAFE for breast-feeding women when used in amounts not larger than 2 mg per day (the recommended dietary allowance). Avoid using higher amounts. Not enough is known about the safety of vitamin B6 at higher doses in breast-feeding women.

Procedures to widen narrowed arteries (angioplasty). Using vitamin B6 along with folic acid and vitamin B12 intravenously (by IV) or by mouth might worsen narrowed arteries. Vitamin B6 should not be used by people recovering from this procedure.

Diabetes. Using vitamin B6, folic acid, and vitamin B12 might increase the risk of cancer in people with diabetes and a recent stroke. Vitamin B6 should not be used by patients with diabetes that have had a recent stroke.