| Vitamin :: Folic Acid |
| Other Terms: | Folate | Folacin | Pteroylglutamic Acid | Vitamin B9 |
| Solubility: | Water soluble. A small amount can be stored in the liver, and excess is excreted in urine. |
| On this Page: | What is Folic Acid · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity | Overdose |
What is Folic Acid ?
It is one of the B complex vitamins. It is also known as folate, or folacin, or vitamin B9.
It takes its name from the Latin word “folium” for leaf, as leafy vegetables were one of the earliest sources from which it was isolated.
Folate is the natural form of the vitamin found in food such as citrus fruits, dark green leafy vegetables, and beans. Folic acid is the synthetic form that is used in supplements and fortified foods.
While folic acid is well absorbed by the body, natural folate is only partly absorbed as its chemical structure requires the action of enzymes in the intestine to change it to the folic acid form that can be taken in. About 50% of folate in food is absorbed compared with 85% of supplemental folic acid when taken with some food.
Animal folate in organ meat is relatively stable to heat, but up to 40% of plant folate is lost during cooking. Processed grains lose up to 70% folate.
How Folic Acid Benefits Health
Folic acid is essential to sustain life and proper growth and development.
One vital function of folic acid is to maintain healthy blood circulation. It lowers levels of homocysteine in blood by converting the homocysteine to other useful substances.
High levels of homocysteine are associated with arteriosclerosis and risk of heart attacks, stroke, blood clot formation, and osteoporosis-related bone fractures. Daily intake of folic acid is often suggested as a way to reduce risk of cardiovascular disease by preventing build-up of homocysteine.
Research also shows a link between folic acid and neurological health. High homocysteine levels can cause deterioration of brain cells, that contribute to dementias such as Parkinson’s and Alzheimer’s disease.
In some recent case studies, patients with the lowest levels of folate were found to have 3 times the risk of cognitive impairment, and 4 times the risk of dementia.
Folic acid is especially important in pregnancy.
Adequate intake is needed to protect against neural tube birth defects in the fetus. Such defects can cause malformations of the skull, the spine (spina bifida), and the brain (anencephaly), which are among the most serious and frequently occurring birth defects.
Spina bifida happens when the spinal column does not close to protect the spinal cord. This closing should take place in the first weeks of pregnancy. If it does not, neurological problems, and often mental retardation, results.
In anencephaly, the fetus’ brain does not develop properly, and most of the brain tissue is missing. It results in stillbirth, or death soon after birth.
There is significant reduction in the risk of neural tube defects when folic acid is consumed in the month or two before conception, and during the first trimester of pregnancy.
Many women are unaware of the importance of folic acid, and that, to be effective folic acid must be present in the first weeks of pregnancy. Often deficiency is only diagnosed after a baby is born with a neural tube defect.
For that reason, the American Academy of Pediatrics and the U.S. Public Health Service (PHS) now advise all women capable of becoming pregnant to take 400 micrograms (µg) of folic acid as part of their diet every day. (Upon pregnancy, the RDA increases to 600 µg.)
The PHS also suggests daily use of folic acid supplements, in addition to a healthy diet, to ensure the proper level of the nutrient.
This list summarizes the main ways that folic acid benefits the body. Folic acid works best in combination with vitamin B12.
| :: | Folic acid Benefits & Functions |
| 1. | has been shown to be important for cardiovascular health by working with vitamins B6 and B12 to prevent build-up of homocysteine in the blood and so reduce risks of heart attacks, strokes, blood clot formation |
| 2. | lowers homocysteine level which decreases risk of dementias such as Alzheimer’s disease, and osteoporosis related bone fractures |
| 3. | considered a brain food |
| 4. | involved in production of neurotransmitters such as dopamine and serotonin that regulate the brain in areas like appetite, mood, sleep |
| 5. | needed for energy production |
| 6. | needed for metabolism of amino acids and synthesis of proteins |
| 7. | functions as a coenzyme in the synthesis of genetic DNA and RNA, and is needed for production of all body cells and healthy tissue growth |
| 8. | especially critical during stages of rapid cell replication and growth such as in pregnancy and infancy |
| 9. | essential for proper development of the skeleton, brain, and spinal cord of the fetus; reduces the risk of birth defects (such as spina bifida and anencephaly) but must be taken by the mother before conception and in early pregnancy |
| 10. | needed for formation of white and red blood cells, and prevention and treatment of folic acid anemia |
| 11. | promotes healthy skin and nails due to role in cell production |
| 12. | protects the linings in body cavities like the mouth and intestinal tract |
| 13. | supplements may be used to treat ulcers of the leg |
| 14. | studies suggest that folic acid supplements help prevent DNA damage linked to risk of breast, colon, cervical, lung, and pancreatic cancer |
| 15. | may improve symptoms of vitiligo (loss of skin pigment) when used with vitamin B12 |
Folic Acid Deficiency Symptoms and Causes
Folic acid deficiency is one of the most widespread deficiencies. It could be caused by a diet low in folate, or by malabsorption that prevents the body from using the folate in food.
Even where there is sufficient intake of folate itself, deficiency of other B vitamins such as B1, B2 and B3, which are needed for folate recycling, can contribute to folic acid deficiency symptoms.
Other factors can interfere with folate absorption or increase its excretion by the kidney and contribute to deficiency. These include viral infections, prolonged stress, excessive alcohol, smoking, and coffee. A higher folate intake through the diet or fortified foods, or from folic acid supplements, may help the health of those affected.
Other medical conditions that require higher folate intake :
- pregnancy and breastfeeding
- kidney dialysis or chronic liver disease, both of which increase excretion and loss of folic acid
- long term use of anti-convulsant drugs such as dilantin, phenytoin and primidone
- long term use of metformin to control blood sugar in type 2 diabetes
- prolonged use of barbiturates
- use of methotrexate, usually prescribed for cancer and ailments like rheumatoid arthritis and psoriasis
- anti-inflammatory medication for conditions like Crohn’s disease and ulcerative colitis
- long term use of estrogen or oral contraceptives
The elderly are at more risk of folate deficiency. In a study of men and women aged over 65, Canadian researchers found that over 50% of the men, and 60% of the women, were at risk of deficiency. This can cause or worsen the mental difficulties they face. Studies show a link between folate levels and mental function.
One of the classic folic acid deficiency symptoms is anemia. However, as red blood cells have a lifespan of 120 days, folic acid levels can be low for some time before anemia results. Checking for folic acid deficiency through anemia testing may therefore not be timely.
The main folic acid deficiency symptoms are summarized here.
| :: | Folic Acid Deficiency Symptoms |
| 1. | megaloblastic macrocytic anemia due to DNA defects, leading to red blood cells that are defective and carry less oxygen than normal, and characterized by breathlessness, heart palpitation, insomnia, irritability, forgetfulness, lethargy, stomach disorders, pallor and sensitivity to cold |
| 2. | chronic muscular fatigue or general weakness |
| 3. | affects production of neurotransmitters, leading to behavorial or mood disorders with symptoms of irritability, hostility, non-senile dementia, confusion, insomnia, mental fatigue, depression, and nervous system problems of the hands and legs such as restless leg syndrome |
| 4. | problems in cell creation especially those with short life spans such as skin cells, causing skin disorders like seborrheic dermatitis and vitiligo (loss of pigment leading to white patches on the skin) |
| 5. | problems in cell creation can cause protective linings of body cavities to be defective, leading to gastro-intestinal tract problems like periodontal disease, gingivitis, mouth and peptic ulcers, diarrhea, loss of appetite, digestive upsets, and reduced absorption of nutrients |
| 6. | swollen or sore or smooth red tongue (glossitis) |
| 7. | studies indicate that low levels of folic acid may contribute to cervical dysplasia in women, and put them at greater risk of cervical cancer from factors such as smoking and HPV infection |
| 8. | premature grey hair |
| 9. | studies have found correlation between low levels of folic acid with high levels of homocysteine and risk of death from coronary heart disease |
| 10. | deficiency can slow overall growth rate of infants and children |
| 11. | shortage of folic acid just before or in early pregnancy can cause low birth weight or premature infants, and neural tube defects resulting in severe brain or neurological disorders of the fetus |
Folic Acid Foods
Foods high in folic acid · organ meat like animal liver or kidney · legumes (peas and dried beans such as adzuki beans, black beans, cranberry beans, chickpeas or garbanzo beans, dal, kidney beans, lentils, mung beans, navy beans, pinto beans) · dark-green leafy vegetables including asparagus, beets, broccoli, collard greens, cauliflower, mustard greens, parsley, romaine lettuce, spinach, turnip greens.
Other folic acid foods
· avocadoes · bananas · cantaloupe · citrus fruits like oranges and lemons · dates · egg · nuts · papaya · poultry and pork · root vegetables like okra · salmon · shellfish · tuna · wheat bran · wheat germ · whole grains like brown rice and whole wheat · yeast · vegetables such as cabbage, green peas, leeks, red bell peppers, squash, string beans, tomatoes.
Folic Acid Supplements
Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins. They work synergistically, which means that the effectiveness of any one nutrient requires or is enhanced, sometimes dramatically, by the presence of certain other nutrients.
For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs.
For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible.
Keep in mind, however, that while vitamin supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle.
Folic Acid RDA (Recommended Dietary Allowance)
The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Folic Acid as follows.
| Life Stage | Gender | Folic Acid Dosage | Day |
| Infants 0-6 mths | 65* µg |
| Infants 7-12 mths | 80* µg |
| Children 1-3 yrs | 150 µg |
| Children 4-8 yrs | 200 µg |
| Girls 9-13 Yrs | 300 µg |
| Boys 9-13 Yrs | 300 µg |
| Females 14-18 Yrs | 400 µg |
| Males 14-18 Yrs | 400 µg |
| Females 19-50 Yrs | 400 µg |
| Males 19-50 Yrs | 400 µg |
| Females older than 50 Yrs | 400 µg |
| Males older than 50 Yrs | 400 µg |
| Pregnant Women 14-18 Yrs | 600 µg |
| Pregnant Women 19-50 Yrs | 600 µg |
| Lactating Mothers 14-18 Yrs | 500 µg |
| Lactating Mothers 19-50 Yrs | 500 µg |
These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Folic Acid toxicity levels.
Legend
1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram
1 mg = 1 milligram = 1/1,000 of a gram
* Indicates AI figures based on Dietary Reference Intake (DRI) figures
Folic Acid Overdose Symptoms, Toxicity Level & Side Effects
Folic acid toxicity is rare. It is water soluble, so excess intake is normally excreted in urine. However folic acid side effects have been reported at doses above 2 mg.
Possible folic acid overdose symptoms include general ill-feeling, allergic skin reactions, insomnia, irritability, and intestinal problems like nausea, loss of appetite, flatulence and abdominal distension.
In its 1998 recommendations the Food and Nutrition Board of the Institute of Medicine set Tolerable Upper Intake Levels (ULs) for folate. These are the highest average daily intake levels above which there is risk of folic acid side effects.
| Life Stage | Tolerable Upper Intake Levels (UL) per Day |
| 0 to 12 months | *ND |
| 1 to 3 years | 300 µg |
| 4 to 8 years | 400 µg |
| 9 to 13 years | 600 µg |
| 14 to 18 years** | 800 µg |
| 19 years & above** | 1000 µg |
*ND : Not determinable. Intake should be from food/milk only.
**Includes pregnant and breastfeeding women.
The ULs apply to synthetic folic acid from supplements and fortified foods. There is no risk or UL for natural folate from food.
Intake of folic acid supplements should not exceed these ULs per day, as high doses can hide anemia symptoms of vitamin B12 deficiency. This can delay diagnosis of B12 deficiency, leading to permanent nerve damage.
Adults older than 50 need to be aware of this relationship between vitamin B12 and folic acid, as they are at greater risk of B12 deficiency. Those taking folic acid supplements should consider taking vitamin B12 too.
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References
| 1. | Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academy Press; 1998. |
| 2. | U.S. National Libary of Medicine [NLM] & National Institutes of Health [NIH]: MedlinePlus. NLM-NIH home page. <http://www.nlm.nih.gov/medlineplus>. Use the built-in search function to find specific data. Accessed 2009 March – June. |
| 3. | National Institutes of Health, NIH Clinical Center: Office of Dietary Supplements [ODS]. ODS home page. <http://ods.od.nih.gov>. Use the built-in search function to find specific data. Accessed 2009 Mar – Jun. |
| 4. | The George Mateljan Foundation: The world’s healthiest foods [WHFoods]. WHFoods home page. <http://www.whfoods.com>. Accessed 2009 March – June. |
| 5. | Mayo Foundation for Medical Education and Research. Mayo Clinic book of alternative medicine: The new approach to using the best of natural therapies and conventional medicine. New York, NY: Time Inc; 2007. p 67-75. |
| 6. | Balch JF, Balch PA. Prescription for nutritional healing: A practical A-Z reference to drug-free remedies using vitamins, minerals, herbs & food supplements. Garden City Park, New York: Avery Publishing; 1990. |
| 7. | Ulene A. Dr. Art Ulene’s complete guide to vitamins, minerals and herbs. New York, NY: Avery Publishing; 2000. |
| 8. | The Editors Of Prevention Health Books. Prevention’s healing with vitamins: The most effective vitamin and mineral treatments for everyday health problems and serious disease. Emmaus, Pennsylvania: Rodale Press; 1996. |
