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Also Known As: folate, folic acid, folacin
Vitamin B9, also called folic acid or folate, is one of eight water-soluble B
vitamins. All B vitamins help the body to convert carbohydrates into glucose
(sugar), which is "burned" to produce energy. These B vitamins, often referred
to as B complex vitamins, are essential in the breakdown of fats and protein. B
complex vitamins also play an important role in maintaining muscle tone along
the lining of the digestive tract and promoting the health of the nervous
system, skin, hair, eyes, mouth, and liver.
Folic acid is crucial for proper brain function and plays an important role
in mental and emotional health. It aids in the production of DNA and RNA, the
body's genetic material, and is especially important during periods of high
growth, such as infancy, adolescence and pregnancy. Folic acid also works
closely together with vitamin B12 to regulate the formation of red blood cells
and to help iron function properly in the body.
Vitamin B9 works closely with vitamins B6 and B12 as well as the nutrients
betaine and S-adenosylmethionine (SAMe) to control blood levels of the amino
acid homocysteine. Elevated levels of this substance appear to be linked to
certain chronic conditions such as heart disease and, possibly, depression and
Alzheimer's Disease. Some researchers have even speculated that there is a
connection between high levels of this amino acid and cervical cancer, but the
results of studies regarding this have been inconclusive.
Folic acid deficiency is the most common B vitamin deficiency. Animal foods,
with the exception of liver, are poor sources of folic acid. Plant sources rich
in folic acid are frequently not obtained in adequate amounts in the diet.
Alcoholism, irritable bowel syndrome, and celiac disease contribute to
deficiency of this important nutrient. Folic acid deficiency can cause poor
growth, tongue inflammation, gingivitis, loss of appetite, shortness of breath,
diarrhea, irritability, forgetfulness, and mental sluggishness.
Pregnancy can put a woman at risk for folic acid deficiency as the fetus
easily depletes a mother's nutrient reserves.
Folic acid deficiency during pregnancy increases the risk for neural tube
defects including cleft palate, spina bifida, and brain damage. Neural tube
defects are birth defects caused by abnormal development of the neural tube, a
structure that eventually gives rise to the central nervous system (the brain
and spinal cord). In 1996, the U.S. Food and Drug Administration (FDA)
authorized the addition of folic acid to many grain foods (such as bread and
cereal). Since this time, the prevalence of neural tube defects in the United
States has decreased.
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Birth Defects As mentioned, pregnant women who are deficient in folic acid
are more likely to have children with birth defects. Many neural tube defects
(such as spina bifida) are believed to be preventable if women of childbearing
age supplement their diets with folic acid. This is why women planning on
becoming pregnant should be taking a multivitamin with plenty of folate, and why
all pregnant women receiving prenatal care are put on a prenatal vitamin.
Studies have found that women who take folic acid supplements before
conception and during the first trimester may reduce their risk of having
children with neural tube defects by 72% to 100%. A recent study found that the
prevalence of neural tube defects in the United States has decreased by 19%
since the FDA authorized the fortification of grains with folic acid. Even
though this connection seems strong, it is not known whether folic acid or
factors other than this vitamin that contributed to this substantial decline.
Recent studies in test tubes brings into question whether there is a
connection between elevated homocysteine (and, therefore, folate deficiency) in
the mother and Down's syndrome in the child. Preliminary information also raises
question about the possibility of folate supplements during pregnancy preventing
the development of childhood leukemia. More research is needed in both of these
areas before any conclusions can be drawn.
Miscarriage Clinically, many naturopathic and other doctors recommend the use
of vitamin B complex 50 mg per day with additional folic acid 800 to 1,000 mcg
per day to try to prevent miscarriage (also known as spontaneous abortion).
These practices for prevention of spontaneous abortion are supported by some
studies suggesting a connection between impaired homocysteine metabolism and
recurrent miscarriages. This conclusion is not without debate, however, with
some experts arguing that it is difficult to determine from most studies to date
whether it is low folate or other factors contributing to an increased incidence
of spontaneous abortion. It is important to know that there are many, many
reasons for a miscarriage. In fact, most commonly, there is no explanation for
why a woman has miscarried.
Heart Disease Folate can help protect the heart through several methods.
First, there are studies that suggest that folate can help reduce risk factors
for heart disease and the harm that they cause, including cholesterol and
homocysteine (both of which can damage blood vessels). Secondly, by diminishing
this damage, studies suggest that not only can folate help prevent build up of
atherosclerosis (plaque), it may also help the blood vessels function better,
improve blood flow to the heart, prevent cardiac events such as chest pain
(called angina) and heart attack, and reduce the risk of death.
Collectively, many studies indicate that patients with elevated levels of the
amino acid homocysteine are roughly 1.7 times more likely to develop coronary
artery disease (coronary arteries supply blood to the heart, blockage there can
lead to a heart attack) and 2.5 times more likely to suffer from a stroke than
those with normal levels. Homocysteine levels can be reduced by taking folate
(the general recommendation is at least 400 micrograms [mcg] per day, but some
studies suggest that this daily amount must be at least 650 to 800 mcg.) Folate
needs vitamins B6 and B12 and betaine to function properly and to fully
metabolize homocysteine.
The American Heart Association recommends that, for most people, an adequate
amount of folate and these other 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 in
someone who already has heart disease or who has a strong family history of
heart disease that developed at a young age.
Alzheimer's Disease
Folic acid and vitamin B12 are critical to the health of
the nervous system and to a process that clears homocysteine from the blood. As
stated earlier, homocysteine may contribute to the development of certain
illnesses such as heart disease, depression, and
Alzheimer's Disease. Elevated
levels of homocysteine and decreased levels of both folic acid and vitamin B12
have been found in people with Alzheimer's Disease, but the benefits of
supplementation for this or other types of dementia are not yet known.
Osteoporosis Keeping bones healthy throughout life depends on getting
sufficient amounts of specific vitamins and minerals, including phosphorous,
magnesium, boron, manganese, copper, zinc, folic acid, and vitamins C, K, B12,
and B6.
In addition, some experts believe that high homocysteine levels may
contribute to the development of osteoporosis. If this is the case, then there
may prove to be a role for dietary or supplemental vitamins B9, B6, and B12.
Vitamin B9 and depression
Studies suggest that vitamin B9 (folate) may be associated with
depression more than any other nutrient, and may play a role in the high
incidence of depression in the elderly. 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 recommend a B complex
multivitamin that contains folate as well as vitamins B6 and B12 to improve
symptoms. If the multivitamin with these B vitamins is not enough to bring
elevated homocysteine levels down, the physician may then recommend higher
amounts of folate along with vitamins B6 and B12. Again, these three nutrients
work closely together to bring down high homocysteine levels, which may be
related to the development of depression.
Cancer Folic acid appears to protect against the development of some forms of
cancer, particularly cancer of the colon, as well as breast, esophagus, and
stomach, although the information regarding stomach cancer is more mixed. It is
not clear exactly how folate might help prevent cancer. Some researchers
speculate that folic acid keeps DNA (the genetic material in cells) healthy and
prevents mutations that can lead to cancer.
Population-based studies have found that colorectal cancer is less common
among individuals with very high dietary intakes of folic acid. The reverse
appears to be true as well: low folic acid intake increases risk of colorectal
tumors. To have a significant effect on reducing the risk of colorectal cancer,
it appears that at least 400 mcg of folic acid per day over the course of at
least 15 years is required. Similarly, many clinicians recommend folic acid
supplementation to people who are at high risk for colon cancer (for example,
people with a strong family history of colon cancer).
Similarly, one population-based study also found that cancers of the stomach
and esophagus are less common among individuals with high intakes of folic acid.
Researchers interviewed 1095 patients with cancer of the esophagus or stomach as
well as 687 individuals who were free of cancer in three health centers across
the United States. They found that patients who consumed high amounts of fiber,
beta-carotene, folic acid, and vitamin C (all found primarily in plant-based
foods) were significantly less likely to develop cancer of the esophagus or
stomach than those who consumed low amounts of these nutrients. Another
important, good-sized study, however, did not find any connection between folic
acid intake and stomach cancer. The possibility of some protection from folate
against stomach cancer in particular needs clarification and, therefore, more
research is warranted.
Low dietary intake of folate may increase the risk of developing breast
cancer, particularly for women who drink alcohol. Regular use of alcohol (more
than 1 ½ to 2 glasses per day) is associated with increased risk of breast
cancer. One extremely large study, involving over 50,000 women who were followed
over time, suggests that adequate intake of folate may lessen the risk of breast
cancer associated with alcohol.
Cervical Dysplasia Folate deficiency appears to be linked to cervical
dysplasia (changes in the cervix [the first part of the uterus] that are either
precancerous or cancerous and generally detected by pap smear). Studies
evaluating the use of folate supplementation to lower the risk of developing
such changes to the uterus have not been promising, however. For now, experts
recommend getting adequate amounts of folate in the diet for all women (see How
To Take It), which may be particularly important for those with risk factors for
cervical dysplasia such as an abnormal pap smear or genital warts.
Inflammatory Bowel Disease (IBD) People with ulcerative colitis and Crohn's
disease (both inflammatory bowel diseases) often have low levels of folic acid
in their blood cells. This may be due, at least in part, to sulfasalazine and/or
methotrexate use, two medications that can diminish levels of folate. Other
researchers speculate that folate deficiencies in Crohn's disease patients may
be due to decreased intake of folate in the diet and poor absorption of this
nutrient in the digestive tract.
Some experts suggest that folic acid deficiencies may contribute to the risk
of colon cancer in those with IBDs. Although preliminary studies suggest that
folic acid supplements may help reduce tumor growths in people with these
conditions, further research is needed to determine the precise role of folic
acid supplementation in people with IBDs.
Burns 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.
Male Infertility
In a study of 48 men, researchers found that men with low sperm counts also
had low levels of folic acid in their semen. It is not clear whether folic acid
supplementation would improve sperm count, however.
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Rich sources of folic acid include spinach, dark leafy greens, asparagus,
turnip, beet and mustard greens, Brussels sprouts, lima beans, soybeans, beef
liver, brewer's yeast, root vegetables, whole grains, wheat germ, bulgur wheat,
kidney beans, white beans, lima beans, mung beans oysters, salmon, orange juice,
avocado, and milk. In March of 1996, the FDA authorized the addition of folic
acid to all enriched grain products and made manufacturers comply to this rule
by January of 1998.
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Vitamin B9 can be found in multivitamins (including children's chewable and
liquid drops), B complex vitamins, or are sold individually. It is a good idea
to take folate as part of or along with a multivitamin because other B vitamins
are needed for folate activation. It is available in a variety of forms
including tablets, softgels, and lozenges. Vitamin B9 is also sold under the
names folate, folic acid, and folinic acid. While folic acid is considered the
most stable form of vitamin B9, folinic acid is the most efficient form for
raising body stores of the nutrient.
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Most people (except pregnant women) get adequate folic acid from their diet.
Under certain circumstances, however, a healthcare professional may recommend a
therapeutic dose as high as 2,000 mcg per day for an adult.
It is important to check with a knowledgeable healthcare provider before
taking supplements and before giving folic acid supplements to a child.
Daily recommendations for dietary folic acid are listed below:
Pediatric
Infants under 6 months: 65 mcg (adequate intake) Infants 7 to 12 months: 80
mcg (adequate intake) Children 1 to 3 years: 150 mcg (RDA) Children 4 to 8
years: 200 mcg (RDA) Children 9 to 13 years: 300 mcg (RDA) Adolescents 14 to 18
years: 400 mcg (RDA) Adult
19 years and older: 400 mcg (RDA) Pregnant women: 600 mcg (RDA) Breastfeeding
women: 500 mcg (RDA) Amounts recommended for heart disease range from 400 to
1,200 mcg.
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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.
Side effects from folic acid are rare. Very high doses (above 15,000 mcg) can
cause stomach problems, sleep problems, skin reactions, and seizures.
Folic acid supplementation should always include Vitamin
B12 supplementation
(400 to 1000 mcg daily) because folic acid can mask an underlying vitamin B12
deficiency, which can cause permanent damage to the nervous system. In fact,
taking any one of the B complex vitamins for a long period of time can result in
an imbalance of other important B vitamins. For this reason, it is generally
important to take a B complex vitamin with any single B vitamin.
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If you are currently being treated with any of the following medications, you
should not use folic acid supplements without first talking to your healthcare
provider.
Antibiotics, Tetracycline Folic acid should not be taken at the same time as
the antibiotic tetracycline because it interferes with the absorption and
effectiveness of this medication. Folic acid 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.)
In addition, long-term use of antibiotics can deplete vitamin B levels in the
body, particularly B2, B9,
B12, and vitamin H (biotin), which is considered part
of the B complex.
Aspirin, Ibuprofen, and Acetaminophen When taken for long periods of time,
these medications, as well as other anti-inflammatories can increase the body's
need for folic acid.
Birth Control Medications, Anticonvulsants, and Cholesterol-lowering
Medications Birth control medications, anticonvulsants for seizures (namely,
phenytoin and
carbamazapine), and cholesterol-lowering medications (namely, bile
acid sequestrants including cholestyramine, colestipol, and colesevelam) may
reduce the levels of folic acid in the blood as well as the body's ability to
use this vitamin. Extra folate when taking any of these medications may be
recommended by your healthcare provider. When taking bile acid sequestrants for
cholesterol, folate should be taken at a different time of day.
Sulfasalazine Sulfasalazine, a medication used for ulcerative colitis and
Crohn's disease, may reduce the absorption of folic acid, leading to lower
levels of folic acid in the blood.
Methotrexate Methotrexate, a medication used to treat cancer and rheumatoid
arthritis, increases the body's need for folic acid. Folic acid reduces the side
effects of methotrexate without decreasing its effectiveness.
Other Antacids, cimetidine, and ranitidine (used for ulcers, heartburn, and
related symptoms) as well as metformin (used for diabetes) may inhibit the
absorption of folic acid. It is best, therefore, to take folic acid at a
different time from any of these medications.
Barbiturates, such as pentobarbital and phenobarbital, used for seizures, may
impair folic acid metabolism.
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list of all supplements, vitamins
Reviewed: 02/2006
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