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 μg 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 μg dietary folate equivalents/d. Increased voluntary bread fortification led to a marginal increase in folate intakes (394 μg dietary folate equivalents/d) and a decline in inadequacy from 37 % to 29 %. Mandatory fortification resulted in an increase of 89 μg folic acid/d, which substantially shifted both the proportion of women with folic acid intakes above 100 μg/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.