The Who, What, Where, When and Sometimes, Why.

Folic Acid

What is it?

Folate and folic acid are forms of a water-soluble B vitamin. Folate occurs naturally in food, and folic acid is the synthetic form of this vitamin. Since 1998, folic acid has been added to cold cereals, flour, breads, pasta, bakery items, cookies, and crackers, as required by federal law. Foods that are naturally high in folate include leafy vegetables (such as spinach, broccoli, and lettuce), okra, asparagus, fruits (such as bananas, melons, and lemons) beans, yeast, mushrooms, meat (such as beef liver and kidney), orange juice, and tomato juice.

Folic acid is used for preventing and treating low blood levels of folate (folate deficiency), as well as its complications, including “tired blood” (anemia) and the inability of the bowel to absorb nutrients properly. Folic acid is also used for other conditions commonly associated with folate deficiency, including ulcerative colitis, liver disease, alcoholism, and kidney dialysis.

Women who are pregnant or might become pregnant take folic acid to prevent miscarriage and “neural tube defects,” birth defects such as spina bifida that occur when the fetus’s spine and back do not close during development. Women also take folic acid before and during pregnancy to prevent other complications such as increased blood pressure during pregnancy and to improve the growth and development of the child.

Some people use folic acid to prevent various types of cancer, including colon cancer or cervical cancer, as well as to reduce nerve pain in people with high levels of blood sugar (diabetes). It is also used to prevent heart disease and stroke, as well as to reduce blood levels of a chemical called homocysteine. High homocysteine levels might be a risk for heart disease.

Folic acid is used for pimples on the skin, gum inflammation, memory loss, Alzheimer’s disease, age-related hearing loss, preventing the eye disease age-related macular degeneration (AMD), reducing signs of aging, weak bones (osteoporosis), a disorder that causes a strong urge to move ones legs (restless legs syndrome; RLS), sleep problems, depression or feeling down, seizures, nerve pain, muscle or bone pain, AIDS, a skin disease called vitiligo, an inflammatory disease called gout, and an inherited disease called Fragile-X syndrome. It is also used for reducing harmful side effects of treatment with the medications nitroglycerin, lometrexol or methotrexate. Folic acid is used to help the body make sperm.

Some people apply folic acid directly to the gum for treating gum infections.

If it is difficult for the patient to take folic acid by mouth, it is sometimes given with a needle for preventing and treating low blood levels of folate (folate deficiency). Folic acid is also given with a needle for chronic fatigue syndrome, a condition with chronic fever, aches, and tiredness.

Folic acid is often used in combination with other B vitamins.

Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The Effectiveness ratings for Folic Acid are as follows:

Effective for…

  • Folate deficiency. Taking folic acid improves folate deficiency.

Likely Effective for…

  • Serious kidney disease. About 85% of people with serious kidney disease have high levels of homocysteine. High levels of homocysteine have been linked to heart disease and stroke. Taking folic acid lowers homocysteine levels in people with serious kidney disease. However, folic acid supplementation does not appear to reduce the risk of heart disease-related events.
  • High amounts of homocysteine in the blood (hyperhomocysteinemia). High levels of homocysteine have been linked to heart disease and stroke. Taking folic acid lowers homocysteine levels by 20% to 30% in people with normal to slightly elevated homocysteine levels. It is recommended that people with homocysteine levels greater than 11 micromoles/L supplement with folic acid and vitamin B12.
  • Reducing harmful effects of a medicine called methotrexate. Taking folic acid seems to reduce nausea and vomiting, which are possible side effects of methotrexate treatment.
  • Birth defects (neural tube defects). Folic acid during pregnancy reduces the risk of neural tube birth defects. It is recommended that pregnant women get 600-800 mcg of folic acid per day from their diet or supplements starting 1 month before pregnancy and during pregnancy. Pregnant women with a history of neural tube birth defects are advised to get 4000 mcg of folic acid per day.

Possibly Effective for…

  • Age-related vision loss (age-related macular degeneration). Research shows that taking folic acid with other vitamins including vitamin B6 and vitamin B12 reduces the risk of developing age-related vision loss.
  • Depression. Limited research shows that taking folic acid along with antidepressants seems to improve symptoms in people with depression.
  • High blood pressure. Research shows that taking folic acid daily for at least 6 weeks reduces blood pressure in people with high blood pressure. But Taking folic acid with blood pressure medication does not seem to lower blood pressure more than taking only blood pressure medicine
  • Gum problems due to a drug called phenytoin. Applying folic acid to the gums seems to prevent gum problems caused by phenytoin. However, taking folic acid by mouth does not seem to improve symptoms of this condition.
  • Gum disease during pregnancy. Applying folic acid to the gums seems to improve gum disease during pregnancy.
  • Stroke. Taking folic acid can reduce the risk of stroke by 10% to 25% in people who live in countries that don’t fortify grain products with folic acid. But folic acid doesn’t seem to prevent strokes in most people who live in countries that do fortify grain products with folic acid.
  • A skin discoloration disorder called vitiligo. Taking folic acid by mouth seems to improve symptoms of vitiligo.

Possibly Ineffective for…

  • Cancer of the white blood cells (acute lymphoblastic leukemia). Taking folate during pregnancy does not reduce the risk of childhood cancer of the white blood cells.
  • Iron deficiency. Taking folic acid with iron supplements is not more effective than taking the iron supplements without folic acid for treating and preventing iron deficiency and anemia caused by too little iron in the body.
  • Memory and thinking skills in older people. Most research shows that taking folic acid does not prevent decline in memory and thinking skills in the elderly.
  • Preventing re-blockage of blood vessels after angioplasty. There is inconsistent evidence on the benefits of taking folic acid after a procedure to widen the blood vessels. But taking folic acid plus vitamin B6 and vitamin B12 might actually interfere with healing in cases where a device (stent) is inserted in the blood vessel to keep it open.
  • Breast cancer. Consuming folate in the diet might lower the risk of developing breast cancer in women who also eat high amounts of methionine, vitamin B12 (cyanocobalamin), or vitamin B6 (pyridoxine), but research is not consistent. Other research suggests that taking folic acid supplements alone does not lower the risk of breast cancer.
  • Heart disease. Most research shows that taking folic acid alone or with other B vitamins does not reduce the risk of death or heart disease-related events in people with heart disease.
  • Cataracts. Research shows that taking folic acid with other vitamins including vitamin B6 and vitamin B12 does not prevent cataracts. In fact, it might increase the chance of needing to have cataracts removed.
  • Chronic fatigue syndrome. Daily injections of folic acid appear to have no effect on symptoms of chronic fatigue syndrome.
  • Diarrhea. Taking a specific nutritional supplement with added folic acid and possibly vitamin B12 does not seem to prevent diarrhea in children at risk of malnutrition. Taking this product may increase the risk of having diarrhea last more than a few days.
  • Preventing falls. Taking folic acid with vitamin B-12 does not seem to prevent falls in older people who are also taking vitamin D.
  • Fetal and early infant death. Taking folic acid during pregnancy does not seem to reduce the risk of having a baby die just before or after birth.
  • Toxicity from the drug lometrexol. Daily injections of folic acid appear to have no effect on symptoms of chronic fatigue syndrome.
  • Lower respiratory tract infections.Taking a specific nutritional supplement with added folic acid and possibly vitamin B12 does not seem to prevent infections in the lungs in children at risk of malnutrition.
  • Weak bones (osteoporosis). In elderly individuals with osteoporosis, taking folic acid with vitamin B12 and possibly vitamin B6 (pyridoxine) does not seem to prevent broken bones.
  • Performance in older people. Taking folic acid with vitamin B-12 doesn’t seem to help older people walk better or have stronger hands.

Likely Ineffective for…

  • Growths in the large intestine and rectum (colorectal adenoma).Taking folic acid supplements does not seem to prevent growths in the large intestine or rectum.
  • Inherited disease called Fragile-X syndrome.Taking folic acid by mouth does not improve symptoms of fragile-X-syndrome.
  • Premature infants. Taking folic acid during pregnancy does not decrease the risk of having a premature baby.

Insufficient Evidence to Rate Effectiveness for…

  • Acne. Limited evidence suggests that taking a specific nutritional supplement, containing vitamin B3 (nicotinamide), a compound isolated from grains (azelaic acid), zinc, vitamin B6 (pyridoxine), copper, and folic acid (NicAzel, Elorac Inc., Vernon Hills, IL) appears to reduce inflammation associated with pimples on the face.
  • Alzheimer’s disease. Limited evidence suggests that elderly people who consume more folic acid than the recommended dietary allowance (RDA) appear to have a lower risk of developing Alzheimer’s disease than people who consume less folic acid.
  • Autism. Limited research suggests taking folic acid during pregnancy might reduce the risk of autism in the child.
  • Beta-thalassemia. Beta-thalassemia is a disorder of the blood that results in the production of less hemoglobin, the protein that carries oxygen in the blood. Patients with beta-thalassemia usually have bone and muscle pain and have less strength. In children with this disorder, limited research suggests taking folic acid by itself, or with L-carnitine a compound similar to an amino acid from protein, might reduce bone pain and help increase strength.
  • Bipolar disorder. Taking folic acid does not appear to improve the antidepressant effects of lithium in people with bipolar disorder. However, taking folate with the medication valproate improves the effects of valproate.
  • Cervical cancer. There is some evidence that increasing folic acid and folate intake from dietary and supplement sources, along with thiamine, riboflavin, and vitamin B12, might help to prevent cervical cancer.
  • Long-term kidney disease (chronic kidney disease, CKD). Taking folic acid might help slow kidney function decline in people with CKD. But it is not beneficial when used along with vitamin B12 (cyanocobalamin). In fact, the combination might make kidney disease worse.
  • Colon cancer, rectal cancer. Research suggests that taking folic acid or eating folate in the diet can reduce the risk of developing colon or rectal cancer. However, there is some research that does not suggest that taking folic acid or folate in the diet offers the same benefit. It is possible that folic acid may be more helpful for preventing colon cancer than rectal cancer or it may be more helpful for specific kinds of colon cancer.
  • Diabetes. Taking folic acid supplements does not seem to benefit people with diabetes.
  • Epilepsy. Taking folic acid does not reduce seizures in people with epilepsy.
  • Esophageal cancer. Research suggests that consuming more folate in the diet lowers the risk for developing esophageal cancer.
  • High amounts of homocysteine in the blood caused by the drug fenofibrate. Taking folic acid every other day might lower levels of homocysteine in the blood caused by the drug fenofibrate.
  • Stomach cancer. Research suggests that taking folic acid reduces the risk of developing some types of stomach cancer.
  • Gout. Early research suggests that folate might reduce the risk of gout.
  • Head and neck cancer. Getting more folic acid from the diet has been linked to a lower risk of head and neck cancer.
  • Hearing loss. Low levels of folate in the blood seem to be related to the risk for sudden hearing loss in adults. Some evidence suggests that taking folic acid daily for 3 years slows the decline of hearing loss in older people who have low folate levels. It is not clear if folic acid supplementation reduces hearing loss in people with normal folate levels.
  • Male infertility. Some research suggests that taking folic acid plus zinc sulfate daily can increase sperm count in men with low sperm counts.
  • Low birth weight. Taking folic acid during pregnancy does not prevent some babies from being born at a low birth weight but it does seem to increase the overall average of birth weights. However, some early research suggests that taking folic acid before getting pregnant might reduce the risk of having a baby that is too small even when born full term. Although this risk is not reduced in mothers that start supplementation after the baby is conceived.
  • Lung cancer. There does not appear to be a relationship between low levels of folic acid and lung cancer in most people.
  • A type of skin cancer called melanoma. Early research shows that taking folic acid might reduce the risk of melanoma.
  • Helping medicines used for chest pain work longer. Some evidence suggests that taking folic acid does not help medications for chest pain (nitrates) work longer.
  • Cleft lip. Some research suggests that taking folic acid during pregnancy lowers the risk of left lip. However, other research shows no effect.
  • Pancreatic cancer. Eating more than 280 mcg of folate in the diet daily is linked to a lower risk of developing pancreatic cancer. However, other research suggests that folate intake is not linked to pancreatic cancer risk.
  • Nerve pain (peripheral neuropathy). There is conflicting evidence about the role of folic acid in nerve pain for people with diabetes (diabetic neuropathy). Some research suggests that taking folic acid with vitamin B6 (pyridoxine) and vitamin B12 improves some symptoms of nerve pain so that people feel happier. However, the nerves do not seem to function any better.
  • Cancer of the throat. Limited research suggests folic acid and folate from dietary and sources and supplements may protect against oropharyngeal cancer, a specific type of throat cancer.
  • Pre-eclampsia. Pre-eclampsia is marked by high blood pressure and protein in the urine during pregnancy. Limited research suggests taking folic acid supplements during pregnancy does not reduce the risk of pre-eclampsia.
  • Pregnancy-induced high blood pressure. Limited research suggests that taking folic acid during pregnancy does not reduce the risk of high blood pressure (gestational hypertension).
  • A disorder that causes a strong urge to move ones legs (restless legs syndrome; RLS). Taking folic acid seems to reduce symptoms of restless legs syndrome. Researchers are studying whether folic acid deficiency causes restless legs syndrome.
  • Schizophrenia. Taking a combination of folic acid and vitamin B12 may reduce some of the negative symptoms associated with schizophrenia, but only in some patients with a specific genetic make-up. In most people, folic acid does not help with these symptoms.
  • Sickle-cell disease. Taking folic acid might lower homocysteine levels. However, it is not known if this will benefit people with sickle-cell disease.
  • Alcoholism.
  • Liver disease.
  • Other conditions.

More evidence is needed to rate folic acid for these uses.

Folate is needed for the proper development of the human body. It is involved in producing the genetic material called DNA and in numerous other bodily functions.

Folic acid is LIKELY SAFE for most people when taken by mouth or injected into the body. Most adults do not experience any side effects when used in doses less than 1 mg daily.

Folic acid is POSSIBLY UNSAFE when taken by mouth in large doses, long-term. High doses of folic acid might cause abdominal cramps, diarrhea, rash, sleep disorders, irritability, confusion, nausea, stomach upset, behavior changes, skin reactions, seizures, gas, excitability, and other side effects.

There is some concern that taking too much folic acid for a long period of time might cause serious side effects. Some research suggests that taking folic acid in doses of 800 mcg to 1.2 mg might increase the risk of heart attack in people who have heart problems. Other research suggests that taking these high doses might also increase the risk of cancer such as lung or prostate cancer.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Folic acid is LIKELY SAFE when taken by mouth appropriately during pregnancy and breast-feeing. Taking 300-400 mcg of folic acid daily is commonly used during pregnancy to prevent birth defects.

Procedures to widen narrowed arteries (angioplasty): Using folic acid, vitamin B6, and vitamin B12 intravenously (by IV) or by mouth might worsen narrowed arteries. Folic acid should not be used by people recovering from this procedure.

Cancer: Early research suggests that taking 800 mcg to 1 mg of folic acid daily might increase the risk of cancer. Until more is known, people with a history of cancer should avoid high doses of folic acid.

Heart disease: Early research suggests that taking folic acid plus vitamin B6 might increase the risk for heart attack in people with a history of heart disease.

Malaria: Early research suggests that taking folic acid plus iron might increase the risk of death or need for treatment in hospital in areas of the world where malaria is common.

Anemia caused by vitamin B12 deficiency: Taking folic acid might mask anemia caused by vitamin B12 deficiency and delay appropriate treatment.

Seizure disorder: Taking folic acid supplements might make seizures worse in people with seizure disorders, particularly in high doses.

5-Fluorouracil

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

There is some concern that taking large amounts of folic acid with 5-fluorouracil might increase some side effects of 5-fluorouracil, especially stomach problems. Talk with your healthcare provider before taking folic acid.

Capecitabine (Xeloda)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

There is some concern that taking large amounts of folic acid might increase the side effects of capecitabine, especially stomach problems like diarrhea and vomiting. Talk with your healthcare provider before taking folic acid.

Fosphenytoin (Cerebyx)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Fosphenytoin (Cerebyx) is used for seizures. The body breaks down fosphenytoin (Cerebyx) to get rid of it. Folic acid can increase how quickly the body breaks down fosphenytoin (Cerebyx). Taking folic acid along with fosphenytoin (Cerebyx) might decrease the effectiveness of fosphenytoin (Cerebyx) for preventing seizures.

Methotrexate (MTX, Rheumatrex)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Methotrexate (MTX, Rheumatrex) works by decreasing the effects of folic acid in the body’s cells. Taking folic acid pills along with methotrexate might decrease the effectiveness of methotrexate (MTX, Rheumatrex).

Phenobarbital (Luminal)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Phenobarbital (Luminal) is used for seizures. Taking folic acid can decrease how well phenobarbital (Luminal) works for preventing seizures.

Phenytoin (Dilantin)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

The body breaks down phenytoin (Dilantin) to get rid of it. Folic acid might increase how quickly the body breaks down phenytoin (Dilantin). Taking folic acid and taking phenytoin (Dilantin) might decrease the effectiveness of phenytoin (Dilantin) and increase the possibility of seizures.

Phenytoin (Dilantin)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

The body breaks down phenytoin (Dilantin) to get rid of it. Folic acid might increase how quickly the body breaks down phenytoin (Dilantin). Taking folic acid and taking phenytoin (Dilantin) might decrease the effectiveness of phenytoin (Dilantin) and increase the possibility of seizures.

Primidone (Mysoline)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Primidone (Mysoline) is used for seizures. Folic acid might cause seizures in some people. Taking folic acid along with primidone (Mysoline) might decrease how well primidone works for preventing seizures.

Pyrimethamine (Daraprim)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Pyrimethamine (Daraprim) is used to treat parasite infections. Folic acid might decrease the effectiveness of pyrimethamine (Daraprim) for treating parasite infections.

Green tea

There is some concern that green tea might keep folic acid from working the way it should in the body. This might lead to a condition that is similar to folic acid deficiency.

Food

Taking folic acid with food reduces its absorption slightly, but probably not enough to be important.

Zinc

Researchers don’t agree on whether or not folic acid interferes with zinc absorption. But for people who get enough zinc in their diet, the effect of folic acid probably isn’t important.

5′-methyltetrahydrofolate, 5′-MTHF, Acide Folique, Acide Ptéroylglutamique, Acide Ptéroylmonoglutamique, Acido Folico, B Complex Vitamin, Complexe de Vitamines B, Complexe Vitaminique B, Dihydrofolate, Folacin, Folacine, Folate, Folinic Acid, L-methylfolate, Methylfolate, Méthylfolate, Pteroylglutamic Acid, Pteroylmonoglutamic Acid, Pteroylpolyglutamate, Tetrahydrofolate, Tétrahydrofolate, Vitamin B9, Vitamine B9.


 

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