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Hart, Rachel. Folic Acid. KNH 413 – Medical Nutrition Therapy II. Miami University, Oxford, Ohio, Spring 2013. Folic Acid (Folate or Vitamin B9) 1. What is the nutrient? Folic acid is a B vitamin that helps the body make new, healthy cells, convert food into energy, maintain proper brain finction, aids in RNA and DNA synthesis, and works with vitamin B12 to help make red blood cells and help iron work properly in the body (National Institutes of Health [NIH], 2013). Folic acid also is extremely important in pregnancy and reduces major birth defects in the fetus. It is a water-soluble vitamin that is not stored in the body and is excreted through the urine. Folic acid is the synthetic form of the vitamin found in fortified foods and dietary supplements, while folate is the naturally occurring form of the vitamin (National Institutes of Health [NIH], 2013). 2. What is the RDA/DRI for the nutrient? Recommended Dietary Allowances (RDA) for Folic Acid Age Birth to 6 months* 7–12 months* 1–3 years Male 65 mcg DFE* 80 mcg DFE* 150 mcg DFE Female Pregnant Lactating 65 mcg DFE* 80 mcg DFE* 150 mcg DFE 4–8 years 200 mcg DFE 200 mcg DFE 9–13 years 300 mcg DFE 300 mcg DFE 14–18 years 400 mcg DFE 400 mcg DFE 19+ years 400 mcg DFE 400 mcg DFE * Adequate Intake (AI) (National Institutes of Health [NIH], 2013) 600 mcg DFE 600 mcg DFE 500 mcg DFE 500 mcg DFE 3. How is the nutrient metabolized? Folic acid is itself not biologically active, but its biological importance is due to tetrahydrofolate and other derivatives after its conversion to dihydrofolic acid in the liver. Folic acid coenzymes play a vital role in DNA metabolism through the synthesis of DNA from its precursors (thymidine and purines), and the synthesis of the amino acid methionine, which is required for the synthesis of a methyl group donor used in many biological reactions. The addition of a methyl (-CH3) group (methylation) to a number of sites within DNA may be important in cancer prevention. Folic acid coenzymes are required for the metabolism of several important amino acids, such as the synthesis of methionine from homocysteine. Folic acid deficiency can therefore result in decreased synthesis of methionine and a buildup of 1 homocysteine; a risk factor for heart disease as well as several other chronic diseases (National Institutes of Health [NIH], 2013). 4. What are food sources of the nutrient? Leafy green vegetables Fruits Dried beans Peas Nuts Enriched breads Enriched cereals Other grain products (National Institutes of Health [NIH], 2013) 5. What disease states alter the nutrients metabolism? Although it is fairly common to have low levels of folic acid, alcoholism, inflammatory bowel disease, and celiac disease can also cause folic acid deficiency (University of Maryland Medical Center [UMMC], 2013). 6. What are the tests or procedures to assess the nutrient level in the body? Folic acid can be measured two ways by a folic acid test. The first test measures the amount of folic acid in the liquid portion of the blood called the plasma. This reflects a person's recent intake of folic acid in the diet. The second measures the amount of folic acid in the red blood cells. This test may be a better way than the plasma test because the amount of folic acid in red blood cells measures the level when the cell was made, as much as 2 months earlier. This level is not usually affected by the amount of folic acid in a person’s diet each day and is the more accurate way to measure the body's level of folic acid (National Institutes of Health [NIH], 2013). 7. What are the drug-nutrient interactions? 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 be taken at different times from tetracycline. Phenytoin (Dilantin) -- Phenytoin, an anti-seizure medication, may lower levels of folate in the body. However, folic acid may interfere with the way phenytoin works, raising the risk of seizures. Pyrimethamine (Daraprim) -- Folic acid may make pyrimethamine, a drug used to prevent and treat malaria and to treat toxoplasmosis, less effective. 2 Chemotherapy medications -- Folic acid may raise the amounts of 5fluorouracil and capecitabine (Xeloda) to dangerous levels in the body. Methotrexate -- Methotrexate, a medication used to treat cancer, rheumatoid arthritis (RA), and psoriasis, reduces the amount of folic acid in the body. Drugs That Lower Levels of Folic Acid -- These drugs may interfere with the body's absorption of folate, and may mean that patients need to take a folic acid supplement. o Antacids o H2 blockers o Proton pump inhibitors o Bile acid sequestrants o Anti-seizure medications o Nonsteroidal anti-inflammatory drugs (NSAIDs) o Sulfasalazine (Azulfidine) o Triamterene (Dyrenium) o Cycloserine o Pyrimethamine (Daraprim) o Trimethoprim (University of Maryland Medical Center [UMMC], 2013) 8. How is the nutrient measured? Folic acid is measured in micrograms per day (mcg/day) (National Institutes of Health [NIH], 2013). 9. What is the UTL? Tolerable Upper Intake Levels (UL) for Folic Acid Age Birth to 6 months 7–12 months 1–3 years Male Not possible to establish* Not possible to establish* 300 mcg Female Pregnancy Lactation Not possible to establish* Not possible to establish* 300 mcg 4– 8 years 400 mcg 400 mcg 9–13 years 600 mcg 600 mcg 14–18 years 800 mcg 800 mcg 800 mcg 800 mcg 19+ years 1,000 mcg 1,000 mcg 1,000 mcg 1,000 mcg *Breast milk, formula, and food should be the only sources of folic acid for infants (National Institutes of Health [NIH], 2013) 3 10. What are the physical signs of deficiency? Folic acid deficiency can cause anemia, poor growth, tongue inflammation, gingivitis, loss of appetite, shortness of breath, diarrhea, irritability, forgetfulness, and mental sluggishness (University of Maryland Medical Center [UMMC], 2013). If pregnant women do not get enough folic acid, their children may suffer from neural tube birth defects, including cleft palate, spina bifida, and brain damage (University of Maryland Medical Center [UMMC], 2013). 11. What are the physical signs of toxicity? At the recommended daily allowance, side effects from folic acid are rare. Very high doses can cause stomach problems, sleep problems, skin reactions, and seizures. People should talk to their doctor before taking more than 800 micrograms of folic acid. Folic acid can hide the symptoms of an underlying vitamin B12 deficiency, which can cause permanent damage to the nervous system. Taking any one of the B vitamins for a long period of time can result in an imbalance of other important B vitamins. For this reason, it is suggested to take a B complex vitamin, which includes all the B vitamins (University of Maryland Medical Center [UMMC], 2013). References 4 Folic acid. (2013). National Institutes of Health [NIH]. Retrieved from http://ods. od.nih.gov/factsheets/Folate-HealthProfessional/ Vitamin B9 (Folic acid). (2013). University of Maryland Medical Center [UMMC]. Retrieved from http://www.umm.edu/altmed/articles/vitamin-b9000338.htm 5