Common Name: Vitamin B6
Synonyms: Pyridoxal, pyridoxamine, pyridoxine

Overview:

Vitamin B6 is a water soluble vitamin that is involved in a great number of life processes in the body. This member of the vitamin B family is responsible for:

1. the metabolism of amino acids and glycogen
2. the synthesis of RNA and DNA
3. The synthesis of hemoglobin
4. The synthesis of sphingolipids
5. The synthesis of the neurotransmitters serotonin, dopamine, norepinephrine, and GABA (gamma-aminobutyric acid).
6. Vitamin B6 has also shown promise in the treatment of atherosclerosis, immune system function.

Vitamin B6 deficiency is often hard to detect in adults. The classic symptoms of a clinical case of vitamin B deficiency are:

1. A microcytic, hypochromic anemia (an anemia where the red cells are smaller and paler than normal).
2. Seizure activity
3. Seborrheic dermatitis
4. irritability
5. Confusions and depression
6. Chapped and cracked lips
7. Glossitis (inflammation of the tongue)
   

Subclinical vitamin B6 deficiency is very common people with malabsorption syndrome, uremia, cancer, heart failure, and cirrhosis, alcoholics and those taking certain medications such as isoniazid, penicillamine, cycloserine, ethionamide and theophylline. Subclinical deficiency is also very common in the elderly who often have very poor eating habits. In the elderly, subclinical deficiency can easily move into the more serious clinical vitamin B6 deficiency.

Benefits

Vitamin B6 has been proven to be extremely helpful:

1. in inhibiting the binding of steroid hormones, such as estrogen and testosterone to receptor sites on cells. This has implications for diseases that are influenced by these hormones such as breast and prostate cancers
2. In cardiovascular disease. Even moderate elevation in blood homocysteine levels is associated with an increase in heart attacks and strokes. Several large observational studies showed that a low intake of vitamin B6 correlated with increased blood homocysteine levels. A large prospective study found that risk of heart attack was 33% less in women who took 4.6mg of B6 daily compared to those who only took 1.1mg daily.
3. In immune system enhancement. Inadequate intake of vitamin B6 has been closely linked to immune system impairment, especially in the elderly. Low B6 levels caused a decrease in the production of lymphocytes (white blood cells that fight infection) and a decrease in interleukin-2 (a protein produced by the body to help white cells do their work). One study found that the amount needed to increase the number of lymphocytes and interleukin-2 were 2.9mg/day for men and 1.9mg/day for women. This is above the RDA limits recommended.
4. In stopping the decline in cognitive function or Alzheimer’s disease in the elderly and an inadequate intake of vitamin B6. One observational study found that higher levels of vitamin B6 levels were associated with better performance in two tests that measured memory.
5. In helping to prevent kidney stones. In a large study that involved over 85,000 women, those whose intake of vitamin B6 40mg or more daily had 2/3rds the risk of developing kidney stones as those who consumed 3mg or less.
6. In treating PMS
7. In treating morning sickness.

Recommended Dosage:

1. For the treatment of heart disease and to lower homocysteine levels a dose of 3mg per day is used.
2. To prevent morning sickness studies have used 10mg per day. This should be determined by consulting with your healthcare provider.
3. Doses to address the other health conditions discussed earlier ranged from 100mg to as much as 18,000mg per day. Doses of B6 above 200mg/day have been known to cause neurological disorders.

Precautions

As there are known neurological problems that can develop when high levels of B6 are used as a supplement, supplementation with B6 should be supervised by a knowledgeable healthcare provider.

Some people have experienced allergic skin reactions with high doses of vitamin B6

Interactions

If you are taking any of the following medications, supplementing with vitamin B6 should not be done before consulting your health care provider.

1. Tetracycline absorption is affected by Vitamin B6. This antibiotic and vitamin B6 should be taken at different times.
2. Vitamin B6 may enhance the effectiveness of tricyclic antidepressants. This is especially true in the elderly.
3. Vitamin B6 may prove useful in treating the side effects that often accompany antipsychotic medications.
4. Vitamin B6 supplementation may be needed with the use of:

• anti-tuberculosis medication such as isoniazid and cycloserine
• oral contraceptives.
• Erythropoietin
• Methotrexate
• penicillamine
• Long term use of theophylline

Taking any of these medications has been shown to lower the B6 levels in the body.

1. Vitamin B6 has been shown to decrease the effectiveness of:

• Levodopa
• Phenytoin
• hydralazine

Web References

1. http://lpi.oregonstate.edu/infocenter/vitamins/vitaminB6/
2. http://www.umm.edu/altmed/ConsSupplements/VitaminB6Pyridoxinecs.html
3. http://en.wikipedia.org/wiki/Vitamin_B6

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