This remarkable nutrient is probably involved in more bodily processes than any other vitamin or mineral. Government surveys indicate, however, that one-third of all adults, and half of all women are not getting enough of this key vitamin in their diets.
What Is It
Vitamin B6, unequivocally the 'workhorse' of nutrients, performs more than
100 jobs innumerable times a day. It functions primarily as a coenzyme, a substance that acts in concert with enzymes to speed up chemical reactions in the cells.
Another name for vitamin B6 is pyridoxine. In supplement form, it is available as pyridoxine hydrochloride or pyridoxal-5-phosphate (P-5-P). Either form satisfies most needs, but some nutritionally oriented physicians prefer P-5-P because it may be better absorbed.
What Does It Do
Forming red blood cells, helping cells make proteins, manufacturing brain chemicals (neurotransmitters) such as serotonin, and releasing stored forms of energy are just a few of the functions of vitamin B6. There is also evidence that vitamin B6 plays a role in preventing and treating many diseases.
• Helps prevent cardiovascular disease and strokes.
• Helps to lift depression.
• Eases insomnia.
• Treats carpal tunnel syndrome.
• May lessen PMS symptoms.
• Helps relieve asthma attacks.
Getting enough B6 through the diet or supplements may help prevent heart disease. Working with folic acid and vitamin B12, this vitamin assists the body in processing homocysteine, an amino acid-like compound that has been linked to an increased risk of heart disease and other vascular disorders when large amounts are present in the blood.
Some women suffering from premenstrual syndrome (PMS) report that vitamin B6 provides relief from many of the symptoms. This beneficial effect probably occurs because of the vitamin's involvement in clearing excess estrogen from the body. And in its role as a building block for neurotransmitters, vitamin B6 may be useful in reducing the likelihood of having epileptic seizures, as well as lifting depression. In fact, up to 25% of people with depression may be deficient in vitamin B6.
In addition, the vitamin maintains nerve health. People with diabetes, who are at risk for nerve damage, can also benefit from B6. Furthermore, it is effective in easing the symptoms of carpal tunnel syndrome, which involves nerve inflammation in the wrist. And for people with asthma, vitamin B6 may reduce the intensity and frequency of attacks; it is especially important for those taking the asthma drug theophylline.
How Much You Need
The RDA for vitamin B6 is 1.3 mg a day for women and men younger than age 50, and 1.5 mg (for women) to 1.7 mg (for men) a day for those older than age 50. Therapeutic doses are higher.
If You Get Too Little: A recent survey found that half of all women fail to meet the RDA for vitamin B6. Women taking oral contraceptives may have especially low levels of this vitamin. Mild deficiencies of B6 can raise homocysteine levels, increasing the risk of heart and vascular diseases. Symptoms of severe deficiency, which is rare, are skin disorders such as dermatitis, sores around the mouth, and acne. Neurological signs include insomnia, depression, and in extreme cases, seizures and brain wave abnormalities.
If You Get Too Much: High doses of vitamin B6 (more than 2,000 mg a day) can cause nerve damage when taken for long periods. In rare cases, prolonged use at lower doses (200 to 300 mg a day) can have the same consequence. Fortunately, nerve damage is completely reversible once you discontinue the vitamin. If you're using B6 for nerve pain, call your doctor if you experience any new numbness or tingling and stop taking the vitamin. Doses up to 100 mg a day are safe, even for long-term use.
How To Take It
Dosage: You can keep homocysteine levels in check with just 3 mg of
B6 a day, but a daily dose of 50 mg is often recommended. Higher doses are needed for therapeutic uses. For PMS: Take 100 mg of B6 a day. For acute carpal tunnel syndrome: Try 50 mg of B6 or P-S-P three times a day.
For asthma: Take 50 mg of B6 twice a day.
Guidelines For Use: Vitamin B6 is best absorbed in doses of no more than 100 mg at one time. When taking higher doses, this more gradual intake will also decrease your chances of nerve damage.
Fish, poultry, meats, chickpeas, potatoes, avocados, and bananas are all good sources of vitamin B6.
Long-term use of high doses of B6 may cause nerve damage.
Facts and Tips
Vitamin B6 supplements can relieve morning sickness in pregnant women. Though the vitamin appears to be safe in the dosages typically recommended (25 mg a day), there have been no studies showing how extra vitamin B6 affects the developing baby. Women troubled by morning sickness should check with their doctor before taking B6.
• A lack of vitamin B6 may cause stress, anxiety, and depression, according to a study of men participating in a bereavement group. Men with low levels of B6 were more distressed and anxious than those with adequate levels. Researchers said that an effective depression treatment may begin with vitamin B6 supplements rather than antidepressant drugs, which can have side effects.
• Vitamin B6 may protect against heart disease, and not just because it lowers levels of the risk-increasing amino acid-like substance homocysteine. One study of 1,550 people from 19 European clinics found that those who placed in the bottom fifth of the group in terms of vitamin B6 levels had twice the risk of heart disease, regardless of their homocysteine levels.