Background

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.

Safety Safety definitions

When taken by mouth: Vitamin B6 is likely safe 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, stomach pain, loss of appetite, headache, and other side effects. Vitamin B6 is possibly unsafe when taken 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.

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 appropriately. The recommended amount during breast-feeding is 2 mg by mouth daily. Avoid using high amounts. There isn't enough reliable information to know if taking high 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.

Effectiveness

Dosing & administration

Vitamin B6 is an important nutrient. Cereal grains, legumes, vegetables, meat, and eggs are good sources of vitamin B6. The amount that should be consumed on a daily basis is called the recommended dietary allowance (RDA). For males, the RDA is 1.3 mg daily for those 19-50 years old, and 1.7 mg daily for those over 50 years. For females, the RDA is 1.3 mg daily for those 19-50 years old, and 1.5 mg daily for those over 50 years. While pregnant, the RDA is 1.9 mg daily. While breast-feeding, the RDA is 2 mg daily. In children, the RDA depends on age.

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.

Interactions with pharmaceuticals

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.

Interactions with herbs & supplements

Herbs and supplements that might lower blood pressure: Vitamin B6 might lower blood pressure. Taking it with other supplements that have the same effect might cause blood pressure to drop too much. Examples of supplements with this effect include andrographis, casein peptides, L-arginine, niacin, and stinging nettle.

Interactions with foods

There are no known interactions with foods.