Vitamin B₆ is a water-soluble vitamin. Our bodies use three forms of vitamin B₆: pyridoxine (PN), pyridoxal (PL), and pyridoxamine (PM). Most of the time you will hear vitamin B₆ referred to as pyridoxine. Vitamin B₆ performs several functions in our body, including breaking down carbohydrates for energy production, and forming hemoglobin and other substances that our bodies need to perform properly.

The possible uses of vitamin B₆ include the following:

• To improve the symptoms of vitamin B₆ deficiency. These symptoms include inflammation (redness, swelling, pain) of the mouth, chapped lips, irritability, depression, and confusion.
• To prevent and treat anemia and nervous systems disorders caused by tuberculosis drugs (eg. isoniazid and cycloserine reduce the levels of vitamin B₆ in the blood) 
• To reduce the symptoms of premenstrual syndrome (PMS)
• To reduce nausea and vomiting during pregnancy
• To prevent heart disease. Recent studies have shown that vitamin B₆, vitamin B₁₂, and folate can lower blood levels of homocysteine, a substance that is an independent risk factor for heart disease.
• To improve symptoms of diabetes (by returning blood glucose levels to the normal range) and reduce the risk of associated complications. 
• To prevent osteoporosis. 

Chicken, fish, kidney, liver, eggs, and pork are excellent sources of vitamin B₆. The following are also good sources of vitamin B₆: yeast, wheat germ, whole grain cereals, beans, potatoes, bananas, and oatmeal. Vitamin B₆ can be lost from food that's frozen or processed (example: luncheon meats).

Vitamin B₆ is available in the form of pyridoxine hydrochloride. It is available as tablets in multivitamin form (including children's chewable), B-complex form, or by itself in dosages ranging from 1 mg to 150 mg. Vitamin B₆ is also found in children's multivitamin liquid drops.

People who eat a balanced diet containing the sources of vitamin B₆ listed earlier should be able to meet the daily requirement without taking a supplement. Consult your health care provider if you have questions about your daily requirement of vitamin B₆. When taking a vitamin supplement, always take it with water, preferably after a meal. As with all medications and supplements, check with a healthcare provider before giving vitamin B₆ supplements to a child.

Daily recommendations for dietary vitamin B₆ are listed below.

Pediatric

• Neonates to 6 months: 0.1 mg (adequate intake) 
• Infants 7 months to 1 year: 0.3 mg (adequate intake) 
• Children 1 to 3 years: 0.5 mg (RDA) 
• Children 4 to 8 years: 0.6 mg (RDA) 
• Children 9 to 13 years: 1 mg (RDA) 
• Males 14 to 18 years: 1.3 mg (RDA) 
• Females 14 to 18 years: 1.2 mg (RDA) 

Adult

• 19 to 50 years: 1.3 mg (RDA) 
• Males 51 years and older: 1.7 mg (RDA) 
• Females 51 years and older: 1.5 mg (RDA) 
• Pregnant females: 1.9 mg (RDA)
• Breastfeeding females: 2 mg (RDA) 

Vitamin B₆ can cause neurological disorders when taken in high doses (200 mg per day or greater) over a long period of time. Discontinuing high doses usually leads to a complete recovery.

Vitamin B₆ supplements taken during chemotherapy with 5-fluorouracil may reduce certain side effects (namely, palmar-plantar erythrodysesthesia, a potentially debilitating skin condition) without affecting the chemotherapy.

Vitamin B₆ decreases the effectiveness of hydralazine, a medication used to treat high blood pressure, and should, therefore, not be taken with this medication.

Vitamin B₆ reduces the effect of levodopa, a medication used to treat Parkinson's disease. Pyridoxine supplements should not be taken with levodopa.

Taking vitamin B₆ supplements may improve treatment with antidepressants such as nortriptyline, especially in elderly patients. However, you should check with your healthcare practitioner before adding new supplements to your existing medication regimen.

Taking vitamin B₆ during treatment with phenytoin, an anticonvulsant medication, may decrease the effectiveness of this medication. You should consult with your healthcare professional before using vitamin B₆ if you are on phenytoin therapy.

B complex vitamins may interfere with the body's ability to absorb tetracycline; these vitamins should not be taken at the same time as this medication.

Antituberculosis medications such as isoniazid (INH) and cycloserine (used for resistant forms of tuberculosis) reduce the levels of vitamin B₆ in the blood. For this reason, it is recommended that you take vitamin B₆ if you are taking these medications, and that your healthcare provider closely monitor you for signs of vitamin B₆ deficiency.

Erythropoietin therapy used for severe anemia may decrease vitamin B₆ levels in red blood cells. Therefore, taking vitamin B₆ supplements may be warranted. You should consult with your doctor if you are currently being treated with this medication.

Penicillamine (used in the treatment of Wilson's disease and rheumatoid arthritis) may decrease levels of vitamin B_6. Long-term penicillamine therapy may warrant monitoring of vitamin B₆ levels in the blood.

Long-term treatment with theophylline for asthma may reduce blood levels of vitamin B₆. Taking supplements may be warranted, but you should check with your healthcare provider first.

Birth control medications and monoamine oxidase inhibitors (MAOIs), medications such as phenelzine and tranylcypromine that are used to treat depression, may reduce blood levels of vitamin B₆.

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