Vitamin B6
Recommended Intake
Vitamin B6 Deficiency
Vitamin B6 Toxicity
Major Food Sources
Health Considerations
Tips for Increasing Your Vitamin B6 Intake

Vitamin B6 is a water-soluble vitamin. Water-soluble vitamins are stored in the body in very limited amounts, and are excreted through the urine. Therefore, it is a good idea to have them in your daily diet. Vitamin B6 exists in three major forms: pyridoxine, pyridoxal, and pyridoxamine. Pyridoxal phosphate (PLP) is the coenzyme form of B6. A coenzyme enables an enzyme to catalyze a reaction. PLP is an essential coenzyme for many protein metabolism reactions.

Vitamin B6's functions include:

• helping amino acid and protein metabolism
• enabling red blood cell metabolism
• helping the nervous system function efficiently
• helping the immune system function efficiently
• converting tryptophan (an amino acid) to niacin (a vitamin)
• enabling the breakdown of glycogen to glucose
• aiding in the metabolism, transportation, and distribution of selenium
• assisting in the metabolism of calcium and magnesium

Recommended Intake:

Vitamin B6 Deficiency
Primary deficiency of vitamin B6 is rare — most foods contain the vitamin. Secondary deficiency may result in certain situations, including malabsorption, alcoholism, some medications, and cigarette smoking. Symptoms of vitamin B6 deficiency include:

• skin inflammation and irritation
• glossitis (sore or inflamed tongue)
• confusion
• depression
• irritability and nervousness
• fatigue and sleepiness
• cheilosis (cracking and scaling of the lips)
• convulsions
• anemia

The following populations may be at risk for vitamin B6 deficiency and may require a supplement:

• The elderly. Many older adults have low blood levels of vitamin B6, which may occur from low intake of the vitamin or accelerated hydrolysis and oxidation of the vitamin.
• People who consume excessive amounts of alcohol. Alcohol impairs the conversion and enhances the hydrolysis of the vitamin.
• People who smoke cigarettes. Cigarette smoking disturbs vitamin B6 metabolism, which contributes to a deficiency. Studies have shown the vitamin level to normalize within two years of quitting smoking.

Vitamin B6 Toxicity
The tolerable upper intake level (UL) for vitamin B6 from dietary sources and supplements combined is 100 mg per day. Symptoms of vitamin B6 toxicity include:

• uncoordinated muscles
• numbness of the hands and feet
• impaired reflexes
• abnormal plasma amino acid levels

Major Food Sources

Health Considerations
Vitamin B6, homocysteine, and heart disease
Homocysteine is an amino acid normally found in the blood. However, studies have shown that elevated blood levels of homocysteine can be a risk factor for heart disease and stroke. Because vitamins B6, B12, and folic acid are required for the metabolism of homocysteine, it is thought that a deficiency of any of the three may increase the level of homocysteine in the blood. It would follow that supplementing with these vitamins may offer protection from heart disease. However, clinical intervention trials are needed to clearly determine this.

Tips for Increasing Your Vitamin B6 Intake
To help increase your intake of vitamin B6:

• Sprinkle kidney beans or garbanzo beans on a salad.
• Opt for a fortified breakfast cereal-one that is high in fiber-in the morning.
• Slice a banana into your oatmeal or cereal.
• If you take a vitamin supplement, make sure it contains vitamin B6.