Vitamin B6
What is it?
Vitamin B6 is a type of B vitamin. Pyridoxine, pyridoxal, and pyridoxamine are all forms of vitamin B6. It’s found in certain foods and also made in a lab.
Vitamin B6 is needed for the proper function of sugars, fats, and proteins in the body. It’s also necessary for the development of the brain, nerves, skin, and many other parts of the body. It’s found in cereals, legumes, and eggs, and often used with other B vitamins in vitamin B complex products.
People commonly use vitamin B6 for preventing and treating vitamin B6 deficiency. It is also used for heart disease, premenstrual syndrome (PMS), depression, morning sickness, Alzheimer disease, menstrual cramps, diabetes, and many other conditions, but there is no good scientific evidence to support many of these other uses.
Is it effective?
Effective for …
- A rare seizure disorder that requires vitamin B6. Giving infants vitamin B6 by IV controls seizures caused by a condition called pyridoxine-dependent epilepsy. IV products can only be given by a healthcare provider.
- 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 …
- High levels of a hormone called prolactin (hyperprolactinemia) caused by antipsychotic drugs. Taking vitamin B6 by mouth reduces levels of prolactin in males with this condition.
- Kidney stones. Taking vitamin B6 by mouth, alone or along with magnesium, can decrease the risk of kidney stones, especially in people with an inherited condition that causes kidney stones.
- Morning sickness. Taking vitamin B6 by mouth improves symptoms of mild to moderate nausea and vomiting during pregnancy. Vitamin B6 plus the drug doxylamine is recommended for those who don’t get better when taking vitamin B6 alone.
- Premenstrual syndrome (PMS). Taking vitamin B6 (pyridoxine) by mouth seems to improve PMS symptoms including breast pain. The lowest effective dose should be used. Higher doses will increase the chance of side effects and aren’t likely to increase benefits.
Possibly Ineffective for …
- Decline in memory and thinking skills that occurs normally with age. Taking vitamin B6 by mouth doesn’t improve mental function in elderly people.
- Alzheimer disease. Taking vitamin B6 supplements by mouth or eating large amounts of vitamin B6 in the diet doesn’t seem to reduce the risk for Alzheimer disease.
- Carpal tunnel syndrome. Taking vitamin B6 by mouth doesn’t seem to reduce symptoms of carpal tunnel syndrome.
- Cataracts. Taking vitamin B6 by mouth, together with folic acid and vitamin B12, doesn’t prevent cataracts. It might even increase the risk of needing to have cataracts removed.
- An adverse skin reaction caused by cancer drug treatment (chemotherapy-induced acral erythema). Taking vitamin B6 by mouth doesn’t seem to prevent this skin reaction in people treated with cancer drugs. Vitamin B6 might also reduce how well certain cancer drugs work.
- Non-cancerous growths in the large intestine and rectum (colorectal adenoma). Taking a combination of folic acid, vitamin B6, and vitamin B12 by mouth doesn’t reduce the risk of developing colorectal polyps.
- Seizures in people with high blood pressure during pregnancy (eclampsia). Taking vitamin B6 by mouth or as a shot doesn’t seem to reduce the risk of seizures during pregnancy. Vitamin B6 shots can only be given by a healthcare provider.
- Weak and brittle bones (osteoporosis). Taking a combination of folic acid, vitamin B6, and vitamin B12 by mouth doesn’t prevent broken bones in people with osteoporosis.
- A pregnancy complication marked by high blood pressure and protein in the urine (pre-eclampsia). Taking vitamin B6 by mouth or as a shot doesn’t seem to reduce the risk of pre-eclampsia. Vitamin B6 shots can only be given by a healthcare provider.
- Preterm birth. Taking vitamin B6 by mouth or as a shot doesn’t seem to reduce the risk of preterm birth. Vitamin B6 shots can only be given by a healthcare provider.
There is interest in using vitamin B6 for a number of other purposes, but there isn’t enough reliable information to say whether it might be helpful.
Is there concern for the safety of its use?
Special Precautions & Warnings:
Pregnancy: Vitamin B6 is likely safe when taken by mouth, appropriately. It’s sometimes used to control morning sickness, but should only be done so under the supervision of a healthcare provider. Taking high doses is possibly unsafe. High doses might cause newborns to have seizures.
Breast-feeding: Vitamin B6 is likely safe when taken in doses of 2 mg by mouth daily. Avoid using higher amounts. There isn’t enough reliable information to know if taking higher doses of vitamin B6 is safe when breast-feeding.
Post-surgical stent placement. Avoid using a combination of vitamin B6, folate, and vitamin B12 after receiving a coronary stent. This combination may increase the risk of blood vessel narrowing.
Weight loss surgery. Taking a vitamin B6 supplement is not needed for people that have had weight loss surgery. Taking too much might increase the chance of side effects such as nausea, vomiting, and browning skin.
Are there any drug interactions?
Amiodarone (Cordarone)
Interaction Rating=Moderate Be cautious with this combination.
Amiodarone might increase sensitivity to sunlight. Taking vitamin B6 along with amiodarone 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.
Vitamin B6 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. Carbidopa prevents this interaction from occurring. If you are taking levodopa without carbidopa, do not take vitamin B6.
Medications for high blood pressure (antihypertensive drugs)
Interaction Rating=Moderate Be cautious with this combination.
Vitamin B6 might lower blood pressure. Taking high doses of vitamin B6 along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.
Phenobarbital (Luminal)
Interaction Rating=Moderate Be cautious with this combination.
Vitamin B6 might increase how quickly the body breaks down phenobarbital. This could decrease the effects of phenobarbital.
Phenytoin (Dilantin)
Interaction Rating=Major Do not take this combination.
Vitamin B6 might increase how quickly the body breaks down phenytoin. Taking vitamin B6 along with phenytoin might decrease the effects of phenytoin and increase the risk of seizures. Do not take large doses of vitamin B6 if you are taking phenytoin.
Are there any interactions with herbs and supplements?
Are there any interactions with food?
What dose is used?
In supplements, vitamin B6 is often used alone and in products containing other B vitamins. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
By what other names is the product known?
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