Integrating the issues of folate bioavailability, intake and metabolism in the era of fortification

The addition of folic acid to foods in the United State Canada and several other countries has yielded improve folate nutritional status and reduced the incidence of neural tube defects. In spite of this success, a number of question remain regarding the bioavailability of natural and added folates and the level of folate intake from dietary sources needed to meet nutritional requirements. Many aspects current folate requirements are being expressed in terms dietary folate equivalents, in which an adjustment employed to account for differences in mean bioavailability of natural and added forms of folate. In this review, we discuss the scientific rationale behind such assumptions and research needs in the broad area of folate bioavailability. We also consider the merits of fortification strategies, including the biofortification of foods.