Folic acid fortification: what does it mean for patients and physicians?

• Published in: Canadian Medical Association journal (CMAJ) 1998-03, Vol.158 (6), p.773-774
• Main Authors: Turner, L A, McCourt, C
• Format: Article
• Language: English
• Subjects: Canada; Edible Grain; Female; Folic Acid - administration & dosage; Folic Acid - adverse effects; Food additives; Food, Fortified - adverse effects; Humans; Infant, Newborn; Neural Tube Defects - prevention & control; Pregnancy; Public Health; Risk Factors; United States; Vitamins & minerals
• ISSN: 0820-3946; 1488-2329

Mulinare J, Cordero JF, Erickson JD, Berry RJ. Periconceptional use of multivitamins and the occurrence of neural tube defects. JAMA 1988;260:3141-5. Milunsky A, Jick H, Jick S, Bruell CL, MacLaughlin DS, Rothman KJ, et al. Multivitamin/folic acid supplementation in early pregnancy reduces the prevalence of neural tube defects. JAMA 1989;262:2847-52. Werler MM, Shapiro S, Mitchell AA. Periconceptional folic acid exposure and risk of occurrent neural tube defects. JAMA 1993;269:1257-61. Czeizel AE, Dudas I. Prevention of first occurrence of neural-tube defects by periconceptional vitamin supplementation. N Engl7 Med 1992;327:1832-5. MRC Vitamin Research Study Group. Prevention of neural tube defects: results of the Medical Research Council vitamin study. Lancet 1991;338:131-7. Herbert V, Biagaouette J. Call for endorsement of a petition to the Food and Drug Administration to always add vitamin B-12 to any folate fortification or supplement. Am J Clin Nutr 1997;65:572-3. It is unknown whether increasing the intake of folic acid by fortification of foods will have the protective effect that has been shown in studies completed to date. In 1 of the 2 randomized controlled trials a much higher dose (4000 (mu)g/day) of folic acid alone, taken as an oral supplement, was shown to prevent neural tube defects in subsequent pregnancies in women whose fetuses had had this problem in an earlier pregnancy.7 In the other study, the risk of a first occurrence of neural tube defect was significantly reduced for women who took a daily multivitamin and multimineral supplement containing 800 pg of folic acid.6 Observational studies have shown that supplements containing about 400 gg folic acid appear to be beneficial,1-6 although the lower limit of effectiveness is unknown. Health Canada has therefore initiated a study to determine whether food fortification is accompanied by a reduction in the detectable incidence of neural tube defects (among live births stillbirths and terminated affected pregnancies) and also whether food fortification leads to an improvement in the blood folate status of women of reproductive age who do not take oral supplements.