Effect of folic acid fortification of foods on folate intake in female smokers with cervical dysplasia

Objective We investigated the effect of folic acid fortification of enriched cereal grains on folate intake in women of predominantly childbearing age at high risk for cervical cancer. Methods Subjects in this cross-sectional study were 77 women randomized between November 1999 and December 2000 in the Womenʹs Intervention to Stay Healthy (WISH), a clinical trial evaluating the effect of a tobacco control intervention on the progression of cervical dysplasia. All subjects were cigarette smokers, had a previously abnormal Papanicolaou test, and were positive for high-risk human papillomavirus at entry. Dietary intake was assessed with food-frequency questionnaires completed at the baseline visit for WISH. The effect of folic acid fortification on folate intake was assessed by using pre- and postfortification folate databases to estimate folate intake. Results Mean folate intake assessed with the postfortification database was 63% higher than intake assessed with the prefortification database: 417 versus 256 μg/d of dietary folate equivalents (P < 0.0001). The proportion of subjects below the estimated average requirement for folate was smaller after fortification than before fortification: 40.3% versus 75.3% (P < 0.0001). Several foods, including white bread, cheese dishes, spaghetti, and rice, became major sources of folate as a result of fortification. Conclusions Folic acid fortification resulted in an increased intake of folate in these subjects. However, even with fortification, folate intake in a large proportion of these women remained below recommended levels. These results should be considered before decisions regarding future levels of folic acid fortification are made.