Ireland has traditionally operated a liberal policy of voluntary fortification, but little is known about how this practice, along with supplement use, affects population intakes and status of folate and vitamin B-12. The aim was to examine the relative impact of voluntary fortification and supplement use on dietary intakes and biomarker status of folate and vitamin B-12 in Irish adults. Folic acid and vitamin B-12 from fortified foods and supplements were estimated by using brand information for participants from the cross-sectional National Adult Nutrition Survey 2008-2010. Dietary and biomarker values were compared between 6 mutually exclusive consumption groups formed on the basis of folic acid intake. The consumption of folic acid through fortified foods at low, medium, and high levels of exposure [median (IQR) intakes of 22 (13, 32), 69 (56, 84), and 180 (137, 248) μg/d, respectively]; from supplements [203 (150, 400) μg/d]; or from both sources [287 (220, 438) μg/d] was associated with significantly higher folate intakes and status compared with nonconsumption of folic acid (18% of the population). Median (IQR) red blood cell (RBC) folate increased significantly from 699 (538, 934) nmol/L in nonconsumers to 1040 (83, 1390) nmol/L in consumers with a high intake of fortified foods (P < 0.001), with further nonsignificant increases in supplement users. Supplement use but not fortification was associated with significantly higher serum vitamin B-12 concentrations relative to nonconsumers (P < 0.001). Two-thirds of young women had suboptimal RBC folate for protection against neural tube defects (NTDs); among nonconsumers of folic acid, only 16% attained optimal RBC folate. The consumption of voluntarily fortified foods and/or supplement use was associated with significantly higher dietary intakes and biomarker status of folate in Irish adults. Of concern, the majority of young women remain suboptimally protected against NTDs.
University College Cork ->