Tiêu thụ axit folic liều cao phải được dưới sự giám sát của bác sĩ bởi vì vẫn còn có ít thông tin về lâu dài các hiệu ứng và triệu chứng của thiếu máu ác tính có thể được che khuất, với tiềm năng dẫn đến thiệt hại thần kinh nghiêm trọng. 4. Bởi vì 4 mg acid folic không ngăn chặn tất cả các NTDs | 3. Consumption of high-dose folic acid must be under a physician s supervision because there is still little information regarding its long-term effects and symptoms of pernicious anemia may be obscured with the potential to result in serious neurologic damage. 4. Because 4 mg of folic acid did not prevent all NTDs in the MRC study patients should be cautioned that folic acid supplementation does not preclude the need for counseling or consideration of prenatal testing for NTDs. C. The American Academy of Pediatrics Committee on Genetics has endorsed the . Department of Health and Human Services 1992 recommendation as follows 1. All women of childbearing age 15-44 years in the United States who are capable of becoming pregnant should consume mg of folic acid per day for the purpose of reducing their risk of having a pregnancy affected by spina bifida or other NTDs. This amount of folic acid is estimated to reduce the NTD risk by 50-70 . This amount mg is also the US Recommended Daily Allowance of folic acid. 2. An intake of 1 mg is not generally recommended. 3. Folic acid should ideally be taken at least 1 month before conception and at least through the first month of gestation. D. Sources of folic acid 1. Dietary. The average diet in the United States contains mg of folate which is less bioavailable than folic acid. Folate intake of mg day can be achieved through careful selection of folate-rich foods spinach and other leafy green vegetables dried beans peas liver and citrus fruits . Some breakfast cereals are fortified with folic acid. Since January 1998 enriched foods including flour cornmeal pasta and rice are fortified in folic acid by order of the US Food and Drug Administration. 2. Supplementation. Folic acid is available over the counter in dosages up to mg. Folic acid is also available by prescription in 1-mg tablets. Prenatal vitamins contain or 1 mg of folic acid. A survey by the March of Dimes revealed that only 27 of .
