|Vitamin B6 (Pyridoxine)
|Also Known As:
|| Pyridoxal, Pyridoxamine, Pyridoxine hydrochloride,
Vitamin B6, also called pyridoxine, is one of eight water-soluble B vitamins.
The B vitamins help the body to convert carbohydrates into glucose (sugar),
which is "burned" to produce energy. These vitamins, often referred to as the B
complex, are also essential in the metabolism of fats and protein. B complex
vitamins also play an important role in maintaining muscle tone in the
gastrointestinal tract and promoting the health of the nervous system, skin,
hair, eyes, mouth, and liver.
Vitamins B12, B6, and B9 (folic acid) work closely together to control blood
levels of the amino acid homocysteine. Elevated levels of this substance appear
to be linked to heart disease. Plus, vitamin B6 is essential for normal brain
development and function, participating in the process of making important brain
chemicals called neurotransmitters.
Pyridoxine is an especially important vitamin for maintaining healthy nerve
and muscle cells and it aids in the production of DNA and RNA, the body's
genetic material. It is necessary for proper absorption of vitamin B12 and for
the production of red blood cells and cells of the immune system. Pyridoxine has
also been called the "woman's vitamin" because it may help relieve symptoms of
premenstrual syndrome (PMS).
In addition to other B complex vitamins, pyridoxine is considered an
"anti-stress" vitamin because it is believed to enhance the activity of the
immune system and improve the body's ability to withstand stressful conditions.
Symptoms of pyridoxine deficiency include muscle weakness, nervousness,
irritability, depression, difficulty concentrating, and short-term memory
Low dietary intake of vitamin B6 is associated
with higher risk of having heart disease. This may be related to the fact that
vitamin B6, together with vitamin B9 (folic acid) and vitamin B12, help to keep
homocysteine levels under control. Homocysteine is an amino acid. Elevated
levels of this amino acid are associated with increased risk of heart disease
and increased risk of stroke.
The American Heart Association recommends, for most people, that enough of
these important B vitamins be obtained from the diet, rather than taking extra
supplements. Under certain circumstances, however, supplements may be necessary.
Such circumstances include elevated homocysteine levels with known heart disease
or strong family history of heart disease at a young age.
Nausea and Vomiting during pregnancy
A recent review of
scientific studies concluded that vitamin B6 may help reduce the severity of
nausea during early pregnancy.
Keeping bones healthy throughout life depends on
getting sufficient amounts of specific vitamins and minerals, including
phosphorous, magnesium, boron, manganese, copper, zinc, folate, and vitamins C,
K, B6, and B12.
Levels of important nutrients are often quite
low in those with anorexia or bulimia. At least 20% of people with anorexia
admitted to a hospital for treatment are deficient in vitamins B2 and B6
(pyridoxine). Some research information suggests that as many as 33% of those
with an eating disorder could be deficient in vitamins B2 and B6. Dietary
changes alone, without additional supplements, can often bring vitamin B levels
back to normal. However, extra B2 and B6 may be required (which will be
determined by your doctor or nutritionist). Plus, B-complex vitamins may help
alleviate stress and reduce symptoms of depression, frequently associated with
It is especially important for people who have sustained
serious burns to obtain adequate amounts of nutrients in their daily diet. When
skin is burned, a substantial percentage of micronutrients may be lost. This
increases the risk for infection, slows the healing process, prolongs the
hospital stay, and even increases the risk of death. Although it is unclear
which micronutrients are most beneficial for people with burns, many studies
suggest that a multivitamin including the B complex vitamins may aid in the
recovery process. Vitamin B6, along with other members of the B complex, may be
of particular importance, given their value in building protein. Protein is
necessary to recover from any kind of an injury. In addition, as stated earlier,
the amount of B complex needed may increase during times of stress.
Studies suggest that vitamin B9 (folate) may be
associated with depression more than any other nutrient. Between 15% and 38% of
people with depression have low folate levels in their bodies and those with
very low levels tend to be the most depressed. Many healthcare providers start
by recommending a multivitamin (MVI) that contains folate, and then monitoring
the homocysteine levels in the blood to ensure the adequacy of therapy. Elevated
homocysteine levels indicate a deficiency of folate even if the levels of folate
in the blood are normal. If the MVI alone is not enough to lower homocysteine
and improve folate function, the provider may suggest additional folate along
with vitamins B6 and B12 to try to bring the homocysteine levels down, thereby
eliminating the functional folate deficiency and, hopefully, helping to improve
feelings of depression.
Premenstrual Syndrome (PMS)
A comprehensive review of studies
concluded that vitamin B6 may be more effective than placebo in improving
symptoms of PMS, particularly depression. Most studies were poorly designed,
however. Still, even though the science is not definitive, many healthcare
providers and their female patients report improvement in PMS from using vitamin
B6. Therefore, how well you respond to vitamin B6 may be very individual. Until
more research is completed, talk with your doctor about whether using B6 is
appropriate and safe for you. Then, if taking the vitamin, follow your symptoms
closely. It can take up to 3 months until any change is noticeable.
Preliminary evidence suggests that vitamin B6 may
help control blood sugar in people with diabetes. In a study of people with
diabetes, those who received pyridoxine alpha-ketoglutarate (a form of vitamin
B6) for one month experienced significant reductions in fasting blood sugar
levels compared to those who did not receive the supplement. More research in
this area is needed before conclusions can be drawn about the relationship
between vitamin B6 and diabetes.
Human Immunodeficiency Virus (HIV)
Vitamin B6, particularly
together with a complete B complex, may help alleviate the stress associated
with having HIV or AIDS.
Attention Deficit/Hyperactive Disorder (ADHD)
of vitamin B6 are required for normal brain development and are essential for
the synthesis of essential brain chemicals including serotonin, dopamine and
norepinephrine. A preliminary study found that pyridoxine was slightly more
effective than methylphenidate (a medication used to treat ADHD) in improving
behavior among hyperactive children. Although intriguing, the results of this
study were not significant and no other studies have been able to confirm these
findings. Therefore, supplementation with vitamin B6 is not considered standard
treatment for ADHD.
Low levels of vitamin B6 have been
associated with rheumatoid arthritis. This may be due to low dietary intake of
vitamin B6 and other important nutrients by people with this joint disorder.
Eating a balanced diet, including a complete vitamin B complex, is a good idea
for anyone with a chronic illness, such as rheumatoid arthritis. It is not known
if taking extra vitamin B6 is of any use if you have arthritis.
Good dietary sources of vitamin B6 include chicken, turkey, tuna, salmon,
shrimp, beef liver, lentils, soybeans, nuts, avocados, bananas, carrots, brown
rice, bran, sunflower seeds, wheat germ, and whole-grain flour.
Vitamin B6 can be found in multivitamins (including children's chewable and
liquid drops), B complex vitamins, or can be sold individually. It is available
in a variety of forms including tablets, softgels, and lozenges. Vitamin B6 is
also sold under the names pyridoxal, pyridoxamine, pyridoxine hydrochloride, and
|How to Take It|
People who eat a balanced diet containing good sources of vitamin B6 should
be able to meet the daily requirement without taking a supplement. Vitamin
supplements should always be taken 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.
- Newborns 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)
- 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: 2.0 mg (RDA)
Prevention of heart disease and lowering of homocysteine levels: 3.0 mg per
Nausea and vomiting during early pregnancy: studies on this topic have used
10 mg per day. The amount to use, however, should be determined together with
Therapeutic doses for some of the conditions discussed in the Uses section
have ranged from 100 to as high as 1,800 milligrams per day. Using doses higher
than 200 mg per day for long periods of time, however, may cause neurologic
Because of the potential for side effects and interactions with medications,
dietary supplements should be taken only under the supervision of a
knowledgeable healthcare provider.
Vitamin B6 can cause neurological disorders, such as loss of sensation in
legs and imbalance, when taken in high doses (200 mg or more per day) over a
long period of time. Discontinuing high doses usually leads to a complete
recovery within 6 months.
There have been extremely rare reports of allergic skin reactions to high
doses of vitamin B6 supplements.
If you are currently being treated with any of the following medications, you
should not use vitamin B6 supplements without first talking to your healthcare
Vitamin B6 should not be taken at
the same time as the antibiotic tetracycline because it interferes with the
absorption and effectiveness of this medication. Vitamin B6 either alone or in
combination with other B vitamins should be taken at different times from
tetracycline. (All vitamin B complex supplements act in this way and should
therefore be taken at different times from tetracycline.)
Antidepressant Medications, Tricyclic
Taking vitamin B6
supplements may improve the effectiveness of certain tricyclic antidepressants
such as nortriptyline, especially in elderly individuals. Other tricyclic
antidepressants include desipramine and imipramine.
On the other hand, another class of antidepressants called monoamine oxidase
inhibitors (MAOIs) may reduce blood levels of vitamin B6. Examples of MAOIs
include phenelzine and tranylcypromine.
Preliminary evidence suggest that
pyridoxine may prove useful in treating tardive dyskinesia, a common but
frustrating side effect from medications used to treat schizophrenia. Tardive
dyskinesia is marked by involuntary movements of the mouth and tongue. More
research is needed to know if vitamin B6 can help prevent or treat this side
Anti-tuberculosis medications such as
isoniazid (INH) and cycloserine (used for resistant forms of tuberculosis)
reduce the levels of vitamin B6 in the blood.
Birth control medications
Birth control medications may reduce blood
levels of vitamin B6.
Vitamin B6 may reduce certain side effects of
5-fluorouracil and doxorubicin, two agents used to treat cancer without reducing
the effectiveness of the chemotherapy.
Erythropoietin therapy used for severe anemia
may decrease vitamin B6 levels in red blood cells. Therefore, vitamin B6
supplementation may be necessary during erythropoietin therapy.
Vitamin B6 decreases the effectiveness of
hydralazine, a medication used to treat high blood pressure.
Vitamin B6 reduces the effectiveness of levodopa, a
medication used to treat Parkinson's disease.
People with rheumatoid arthritis taking this
medication often have low levels of vitamin B6.
Penicillamine, a medication used in the
treatment of rheumatoid arthritis and Wilson's disease (excessive amounts of
copper in the body that can lead to liver damage) may decrease levels of vitamin
B6 in the body.
Vitamin B6 reduces the effectiveness of phenytoin, a
medication used to treat seizures.
Long-term treatment with theophylline for asthma
may reduce blood levels of vitamin B6.
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|Review Date: April 2002|
|Reviewed By: Participants in the review process include: Ruth DeBusk, RD, PhD, Editor,
Nutrition in Complementary Care, Tallahassee, FL; Jacqueline A. Hart, MD,
Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University
and Senior Medical Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh
(Pediatric Dosing section February 2001), Johnson Drugs, Natick, Ma; Steven
Ottariono, RPh (Pediatric Dosing section February 2001), Veteran's
Administrative Hospital, Londonderry, NH. All interaction sections have also
been reviewed by a team of experts including Joseph Lamb, MD (July 2000), The
Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh (August 2000),
Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in Pharmacy (March
2000), Clinical Assistant Professor, University of Maryland School of Pharmacy;
President, Your Prescription for Health, Owings Mills, MD; Ira Zunin, MD, MPH,
MBA (July 2000), President and Chairman, Hawaii State Consortium for Integrative
Medicine, Honolulu, HI.|
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