Vitamin B6

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What is it?

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 anemia that may result. It is also used for heart disease, premenstrual syndrome (PMS), depression, and many other conditions.

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

It is effective?
Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

Effective for …

  • Seizures. Administering vitamin B6 intravenously (by IV) controls seizures in infants that are caused by vitamin B6 dependence.
  • A condition in which the body makes abnormal red blood cells that build up iron (sideroblastic anemia). Taking vitamin B6 by mouth is effective for treating an inherited type of anemia called sideroblastic anemia.
  • Vitamin B6 deficiency. Taking vitamin B6 by mouth is effective for preventing and treating vitamin B6 deficiency.

Probably Effective for …

  • High levels of homocysteine in the blood (hyperhomocysteinemia). Taking vitamin B6 by mouth, usually with folic acid, is effective for treating high homocysteine levels in the blood.

Possibly Effective for …

  • An eye disease that leads to vision loss in older adults (age-related macular degeneration). Some research shows that taking vitamin B6 with other vitamins including folic acid and vitamin B12 might help prevent the loss of vision caused by an eye disease called macular degeneration.
  • Hardening of the arteries (atherosclerosis). As people age, their arteries tend to lose their ability to stretch and flex. Garlic and other ingredients seem to reduce this effect. Taking a specific supplement containing garlic, amino acids (part of proteins), and vitamins such as folic acid, vitamin B12, and vitamin B6 (Kyolic, Total Heart Health, Formula 108, Wakunga) seem to reduce symptoms of hardening of the arteries.
  • Kidney stones. People with a hereditary disorder called type I primary hyperoxaluria have an increased risk of forming kidney stones. There is some evidence that taking vitamin B6 by mouth, alone or along with magnesium, or getting vitamin B6 injected into the vein, can decrease the risk of kidney stones in people with this condition. However, it does not appear to help people with other kinds of kidney stones.
  • Morning sickness. Some research suggests that taking vitamin B6, usually as pyridoxine, improves symptoms of mild to moderate nausea and vomiting during pregnancy. The American College of Obstetrics and Gynecology considers vitamin B6 a first-line treatment for nausea and vomiting caused by pregnancy. Vitamin B6 plus the medication doxylamine is recommended for women who do not get better when treated with just vitamin B6. However, taking this combination is less effective than the medication ondansetron.
  • Premenstrual syndrome (PMS). There is some evidence that taking vitamin B6 as pyridoxine by mouth can improve PMS symptoms including breast pain. The lowest effective dose should be used. Higher doses will increase the chance of side effects and are not likely to increase the beneficial effects.
  • A movement disorder often caused by antipsychotic drugs (tardive dyskinesia). Taking vitamin B6 seems to improve movement disorders in people taking certain drugs for schizophrenia.

Possibly Ineffective for …

  • Decline in memory and thinking skills that occurs normally with age. . One study shows that taking vitamin B6, folic acid, and vitamin B12 might help prevent certain parts of the brain from deteriorating in elderly people. However, most research shows that taking vitamin B6 along with folic acid and vitamin B12 does not improve mental function in elderly people.
  • Alzheimer disease. Early research suggests that higher intake of vitamin B6 from supplements or as part of the diet is not associated with a reduced risk of Alzheimer disease in older people.
  • Autism. Taking vitamin B6 along with magnesium does not seem to improve behavior in children with autism.
  • Carpal tunnel syndrome. Although some early research suggests that taking vitamin B6 might relieve certain symptoms of carpal tunnel syndrome, most research suggests that this supplement does not benefit people with this condition.
  • Cataracts. Research shows that taking vitamin B6 in combination with folic acid and vitamin B12 does not prevent cataracts in women. And it might increase the risk of having the cataracts removed.
  • An adverse skin reaction caused by cancer drug treatment (chemotherapy-induced acral erythema). Hand-foot syndrome is a skin reaction caused by cancer drugs. Taking vitamin B6 doesn’t seem to prevent this skin reaction in people treated with cancer drugs. There’s also concern that vitamin B6 might reduce how well the cancer drugs work.
  • Non-cancerous growths in the large intestine and rectum (colorectal adenoma). Research shows that taking a combination of folic acid, vitamin B6, and vitamin B12 does not reduce the risk of colorectal polyps in women at high risk of heart disease.
  • Weak and brittle bones (osteoporosis). Research shows that taking a combination of folic acid, vitamin B6, and vitamin B12 does not prevent broken bones in people with weak bones (osteoporosis).

Insufficient Evidence to Make a Determination for …

  • Acne. Early research suggests that taking a product containing nicotinamide, azelaic acid, zinc, vitamin B6, copper, and folic acid, reduces lesion swelling and helps with the appearance of acne in adults and children.
  • A procedure to open a blocked or narrowed blood vessel (angioplasty). Evidence on the benefits of vitamin B6 for preventing the re-blockage of blood vessels after angioplasty is inconsistent. Some evidence suggests that taking folic acid, vitamin B12, and vitamin B6 might reduce the re-blockage of blood vessels in people treated with balloon angioplasty. But other research shows no benefit in people who underwent coronary stenting.
  • Asthma. The effectiveness of vitamin B6 supplementation in children with asthma is unclear.
  • Eczema (atopic dermatitis). Early research shows that taking vitamin B6 daily for 4 weeks does not reduce eczema symptoms in children.
  • Attention deficit-hyperactivity disorder (ADHD). Early research shows that taking vitamin B6 by mouth, with or without high doses of other B vitamins, might help ADHD. However, research using high doses of both vitamin B6 and other vitamins seems to have no effect on ADHD symptoms.
  • Cancer. Eating more foods that contain vitamin B6 has been linked with a lower risk of cancer. But taking vitamin B6 along with other vitamins and nutrients doesn’t prevent cancer in people with heart disease or kidney damage.
  • Heart disease. Taking B vitamin combinations that include vitamin B6 does not seem to prevent death or heart attack in people with heart disease. But some recent data shows it might slightly lower the risk of stroke.
  • Cavities. Taking vitamin B6 may reduce the risk of dental cavities during pregnancy.
  • Depression. Eating more food that contains vitamin B6 has been linked with a lower risk of depression. Taking a vitamin B6 supplement doesn’t seem to reduce depression symptoms in most people. But it might reduce the risk of developing depression in women taking birth control pills.
  • Diabetes. Early research suggests that taking vitamin B6 improves blood sugar levels in women who are pregnant and have low levels of vitamin B6. But not all research agrees.
  • Nerve pain in people with diabetes (diabetic neuropathy). There is conflicting evidence about the role of vitamin B6 in people with diabetes-related nerve pain . Some research suggests that taking vitamin B6 (pyridoxine) with thiamine or folic acid and vitamin B12 improves some symptoms of nerve pain so that people feel happier. However, the nerves do not seem to function any better.
  • Menstrual cramps (dysmenorrhea). Early research suggests that taking vitamin B6 daily might reduce painful periods.
  • Seizures in women with pre-eclampsia (eclampsia). Taking vitamin B doesn’t seem to reduce the risk of seizures during pregnancy.
  • High blood pressure. Early research suggests that taking pyridoxine can lower blood pressure in people with high blood pressure.
  • High levels of fats called triglycerides in the blood (hypertriglyceridemia). Early research suggests that taking vitamin B6 does not reduce high levels of blood fats called triglycerides. However, it might slightly reduce cholesterol levels.
  • Insomnia. Some research shows that taking a product containing a protein called casein, plants called zizyphus and hops, as well as magnesium and vitamin B6, does not help people sleep better.
  • Nerve damage caused by a drug for tuberculosis (isoniazid-induced neuropathy). Early research suggests that taking vitamin B6 daily might reduce nerve damage caused by isoniazid, a medication taken for tuberculosis.
  • Breast-feeding. Early research suggests that taking vitamin B6 daily for about one week after giving birth does not stop breast milk production.
  • Lung cancer. People who have higher blood levels of vitamin B6 seem to have a lower risk of lung cancer. This seems to be especially true for men and for people with a history of smoking. It’s unclear if taking vitamin B6 as a supplement can reduce the risk of lung cancer.
  • Nausea and vomiting. Early research suggests that taking vitamin B6 does not reduce nausea or vomiting or improve symptoms of dehydration in children with an infection in the stomach or intestines. However it might reduce the risk of nausea in women taking birth control pills.
  • A pregnancy complication marked by high blood pressure and protein in the urine (pre-eclampsia). Taking vitamin B6 doesn’t seem to reduce the risk of pre-eclampsia.
  • Preterm birth. Taking vitamin B6 doesn’t seem to reduce the risk of preterm birth.
  • Seizures not caused by epilepsy. Early research suggests that taking vitamin B6 daily for 12 months does not reduce the risk of seizures caused by a high fever in children.
  • Stroke. Taking B vitamin supplements that include vitamin B6 might slightly reduce stroke risk in people with heart disease. But it’s unknown which combination of B vitamins has the most benefit.
  • Nerve damage caused by the drug vincristine. One report suggests that vitamin B6 might help reverse nerve damage caused by the chemotherapy drug vincristine. Research is needed to confirm these results.
  • Allergies.
  • Down syndrome.
  • Kidney problems.
  • Long-term swelling (inflammation) in the digestive tract (inflammatory bowel disease or IBD).
  • Lyme disease.
  • Muscle cramps.
  • Night leg cramps.
  • Rheumatoid arthritis (RA).
  • Other conditions.

More evidence is needed to rate vitamin B6 for these uses.

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.

Is there concern for the safety of its use?
When taken by mouth: Vitamin B6 is LIKELY SAFE for most people when used appropriately. Taking vitamin B6 in doses of 100 mg daily or less is generally considered to be safe. Vitamin B6 is POSSIBLY SAFE when taken in doses of 101-200 mg daily. In some people, vitamin B6 might cause nausea, vomiting, diarrhea, stomach pain, loss of appetite, headache, tingling, sleepiness, and other side effects. Vitamin B6 is POSSIBLY UNSAFE when taken by mouth in doses of 500 mg or more daily. High doses of vitamin B6, especially 1000 mg or more daily, might cause brain and nerve problems.

When given by IV: Vitamin B6 is LIKELY SAFE when given by IV under medical supervision for uses approved by the FDA.

When given as a shot: Vitamin B6 is LIKELY SAFE when given as a shot into the muscle under medical supervision in amounts approved by the FDA. Using large doses of vitamin B6 as a shot into the muscle is POSSIBLY UNSAFE. It might cause muscle problems.

Special Precautions & Warnings:

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

Breast-feeding: Vitamin B6 is LIKELY 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.

Weight loss surgery. Taking a vitamin B6 supplement is not needed for people that have had weight loss surgery. And taking too much vitamin B6 might increase the chance of side effects such as nausea, vomiting, and browning skin.

Diabetes. Using a combination of 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.

Are there any drug interactions?

Amiodarone (Cordarone)

Interaction Rating=Moderate Be cautious with this combination.

Amiodarone (Cordarone) might increase your sensitivity to sunlight. Taking vitamin B6 (pyridoxine) along with amiodarone (Cordarone) might increase the chances of sunburn, blistering, or rashes on areas of skin exposed to sunlight. Be sure to wear sunblock and protective clothing when spending time in the sun.

Levodopa

Interaction Rating=Minor Be watchful with this combination.

The body breaks down levodopa to get rid of it. Vitamin B6 (pyridoxine) can increase how quickly the body breaks down and gets rid of levodopa. But this is only a problem if you are taking levodopa alone. Most people take levodopa along with carbidopa (Sinemet). Carbidopa prevents this interaction from occurring. If you are taking levodopa without carbidopa do not take vitamin B6.

Phenobarbital (Luminal)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down phenobarbital (Luminal) to get rid of it. Pyridoxine might increase how quickly the body breaks down phenobarbital (Luminal). This could decrease the effectiveness of phenobarbital (Luminal).

Phenytoin (Dilantin)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down phenytoin (Dilantin) to get rid of it. Pyridoxine (vitamin B6) might increase how quickly the body breaks down phenytoin. Taking pyridoxine (vitamin B6) and taking phenytoin (Dilantin) might decrease the effectiveness of phenytoin (Dilantin) and increase the possibility of seizures. Do not take large doses of pyridoxine (vitamin B6) if you are taking phenytoin (Dilantin).

Are there any interactions with herbs and supplements?
Herbs and supplements that might lower blood pressure: Vitamin B6 might lower blood pressure. Using vitamin B6 along with other herbs and supplements that can lower blood pressure might cause blood pressure to become too low. Some of these herbs include andrographis, casein peptides, cat’s claw, coenzyme Q-10, fish oil, L-arginine, lycium, stinging nettle, theanine, and others.

Are there any interactions with food?
There are no known interactions with foods.

What dose is used?
The following doses have been studied in scientific research:

ADULTS

BY MOUTH:

  • For a condition in which the body make abnormal red blood cells that build up iron (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 high levels of homocysteine in the blood (hyperhomocysteinemia): For reducing high levels of homocysteine in the blood after meals, 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 an eye disease that leads to vision loss in older adults (age-related 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) 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 has been used.
  • For kidney stones: 25-500 mg of vitamin B6 has been used daily.
  • For morning sickness: 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 a movement disorder often caused by antipsychotic drugs (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 THE MUSCLE:

  • A condition in which the body makes abnormal red blood cells that build up iron (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 THE VEIN OR MUSCLE:

  • For seizures: 10-100 mg is recommended for seizures in newborns who are dependent on vitamin B6.

The daily recommended dietary allowances (RDAs) of vitamin B6 are: Infants 0-6 months, 0.1 mg; Infants 7-12 months, 0.3 mg; Children 1-3 years, 0.5 mg; Children 4-8 years, 0.6 mg; Children 9-13 years, 1 mg; Males 14-50 years, 1.3 mg; Males over 50 years, 1.7 mg; Females 14-18 years, 1.2 mg; Females 19-50 years, 1.3 mg; Females over 50 years, 1.5 mg; Pregnant women, 1.9 mg; and breast-feeding women, 2 mg. Some researchers think the RDA for women 19-50 years should be increased to 1.5-1.7 mg per day. The recommended maximum daily intake is: Children 1-3 years, 30 mg; Children 4-8 years, 40 mg; Children 9-13 years, 60 mg; Adults, pregnant and breast-feeding women, 14-18 years, 80 mg; and Adults, pregnant and breast-feeding women, over 18 years, 100 mg.

By what other names is the product known?
Adermine Chlorhydrate, Adermine Hydrochloride, B Complex Vitamin, B6, Chlorhydrate de pyridoxine, Complexe de Vitamines B, Phosphate de Pyridoxal, Phosphate de Pyridoxamine, Piridoxina, Pyridoxal, Pyridoxal Phosphate, Pyridoxal 5 Phosphate, Pyridoxal-5-Phosphate, Pyridoxal-5′-Phosphate, Pyridoxamine, Pyridoxamine Phosphate, Pyridoxamine-5′-Phosphate, Pyridoxine, Pyridoxine HCl, Pyridoxine Hydrochloride, Pyridoxine Phosphoserinate, Pyridoxine-5-Phosphate, Pyridoxine-5′-Phosphate, P5P, P-5-P, Vitamin B-6, Vitamina B6, Vitamine B6.

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