Effect of increasing voluntary folic acid food fortification on dietary folate intakes and adequacy of reproductive-age women in New Zealand

Objective: Mandatory folic acid fortification of breads in New Zealand was put on hold in 2009. At this time, bread manufacturers were requested to adopt greater voluntary fortification and agreed to add folic acid to approximately one-third of their bread range. We sought to evaluate the impact of increased voluntary fortification of bread and the proposed mandatory fortification programme on folate intake adequacy of reproductive-age women. Design: Cross-sectional study conducted in 2008. Dietary data were collected using 3 d weighed food records and usual folate intakes were generated by modifying the food composition table as follows: (i) voluntary fortification of bread as of 2008 (six breads); (ii) increased voluntary fortification of bread as of 2011 (thirty-four breads); and (iii) mandatory fortification of all breads. The prevalence of inadequate folate intake was calculated for all three scenarios using the Estimated Average Requirement (320 mu g dietary folate equivalents/d) cut-point method. Setting: New Zealand. Subjects: Healthy non-pregnant women (n 125) aged 18-40 years. Results: Usual folate intake in 2008 was 362 mu g dietary folate equivalents/d. Increased voluntary bread fortification led to a marginal increase in folate intakes (394 mu g dietary folate equivalents/d) and a decline in inadequacy from 37 % to 29 %. Mandatory fortification resulted in an increase of 89 mu g folic acid/d, which substantially shifted both the proportion of women with folic acid intakes above 100 mu g/d and the distribution of overall folate intakes, producing a marked reduction in inadequacy to 5%. Conclusions: Increased voluntary bread fortification efforts are far inferior to mandatory fortification as a reliable public health intervention.