Despite the introduction of mandatory folic acid fortification of grains as much as a third of women of childbearing age are not getting the recommended amounts, says a study from Canada.
The new study, published in the current issue of The Journal of Nutrition (Vol. 136, pp. 2820-2826), looked at the effects of fortification on the folate intake of 61 university-educated women (average age 32) during pregnancy (recruited at week 36) and lactation (four and 16 weeks of lactation) based on weighed food records.
The researchers, led by Kelly Sherwood and Deborah O’Connor from the University of Toronto found that the average dietary folate intake during pregnancy was 562 micrograms per day, while average intake during lactation was 498 micrograms per day.
Summary —
Many women are advised to consume a folic acid?containing prenatal supplement for the duration of pregnancy and lactation. Whether this remains necessary after folic acid fortification of the food supply in North America has yet to be determined. Our objective was to assess the dietary folate intake of a sample of pregnant and lactating women at mandated and predicted folic acid?fortification levels and determine the prevalence of inadequate and excessive intakes. Weighed food records (for 3 d) were collected from predominantly university-educated women (32 ? 4 y of age) at 36 wk of pregnancy (n = 61) and at 4 and 16 wk of lactation (n = 60). Dietary folate intakes during pregnancy and lactation, assuming fortification at mandated levels (140?150 ?g/100g), were 562 ? 106 and 498 ? 99 ?g/d dietary folate equivalents (DFE), respectively. The prevalence of inadequacy for folate, or the proportion of individuals with usual folate intakes less than their nutrient requirement, was 36% for women during pregnancy (estimated average requirement of 520 ?g/d DFE), and 32% during lactation (estimated average requirement of 450 ?g/d DFE). Assuming fortification at twice the mandated level, mean dietary intakes during pregnancy and lactation were 786 ? 132 and 716 ? 150 ?g/d DFE, respectively, producing only a 3% prevalence of folate inadequacy. Grains contributed 41% of total folate intake followed by fruits and vegetables (21%). To conclude, at mandated levels of fortification many pregnant and lactating women are unlikely to meet their folate requirements from dietary sources alone; however, the actual level of inadequacy cannot be determined until the level of folic acid in the food supply is known with greater precision.