Folate intake from food is not associated with any health risk. The risk of toxicity from folic acid intake from supplements and/or fortified foods is also low.1 It is a water soluble vitamin, so any excess intake is usually lost in the urine. There is some evidence that high levels of folic acid can provoke seizures in patients taking anti-convulsant medications.2 Anyone taking such medications should consult with a medical doctor before taking a folic acid supplement.
The Institute of Medicine has established a tolerable upper intake level (UL) for folate from fortified foods or supplements (i.e. folic acid) for ages one and above. Intakes above this level increase the risk of adverse health effects. In adults, supplemental folic acid should not exceed the UL to prevent folic acid from triggering symptoms of vitamin B12 deficiency.3 It is important to recognize that the UL refers to the amount of synthetic folate (i.e. folic acid) being consumed per day from fortified foods and/or supplements. There is no health risk, and no UL, for natural sources of folate found in food. Table 4 lists the Upper Intake Levels (UL) for folate, in micrograms (μg), for children and adults.
Table 4: Tolerable Upper Intake Levels for Folate for Children and Adults4
| Age (years) |
Males and Females (μg/day) |
Pregnancy (μg/day) |
Lactation (μg/day) |
|---|---|---|---|
| 1-3 | 300 | N/A | N/A |
| 4-8 | 400 | N/A | N/A |
| 9-13 | 600 | N/A | N/A |
| 14-18 | 800 | 800 | 800 |
| 19 + | 1000 | 1000 | 1000 |
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Disclaimer
Reasonable care has been taken in preparing this document and the information provided herein is believed to be accurate. However, this information is not intended to constitute an "authoritative statement" under Food and Drug Administration rules and regulations.
About Source: ODS
The mission of the Office of Dietary Supplements (ODS) is to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, stimulating and supporting research, disseminating research results, and educating the public to foster an enhanced quality of life and health for the U.S. population.
General Safety Advisory
Health professionals and consumers need credible information to make thoughtful decisions about eating a healthful diet and using vitamin and mineral supplements. These Fact Sheets provide responsible information about the role of vitamins and minerals in health and disease. Each Fact Sheet in this series received extensive review by recognized experts from the academic and research communities.
The information is not intended to be a substitute for professional medical advice. It is important to seek the advice of a physician about any medical condition or symptom. It is also important to seek the advice of a physician, registered dietitian, pharmacist, or other qualified health professional about the appropriateness of taking dietary supplements and their potential interactions with medications.
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Footnotes
- Hathcock JN. Vitamins and minerals: Efficacy and safety. Am J Clin Nutr 1997;66:427-37. [↩]
- Herbert V. Folic Acid. In: Shils M, Olson J, Shike M, Ross AC, ed. Nutrition in Health and Disease. Baltimore: Williams & Wilkins, 1999. [↩]
- Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. National Academy Press. Washington, DC, 1998. [↩]
- Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. National Academy Press. Washington, DC, 1998. [↩]