Phytate Effect and Nutrient Levels in Whole Grain Flours

Abstract

SUMMARY Iron and several B vitamins have been added to refined wheat flour in North America and the United Kingdom since the 1940s to improve public health (2). Now more than 70 countries fortify wheat flour with at least iron or folic acid (11). Folic acid, a form of vitamin B9, has been added to flour since 1996. This has resulted in a 30–70% decline of neural tube defects (12). These birth defects such as spina bifida are permanently disabling or fatal, but they can be mostly prevented if women consume 400 micrograms of folic acid daily at least a month before conception and in the first few weeks of pregnancy. Many countries which fortify wheat flour do not require fortification of whole grain flour. In some places, whole grain flours are not fortified to give consumers a choice between fortified and unfortified grain products. In other countries, whole grain flours are not fortified because whole grain flour retains more of the wheat’s original vitamins and minerals and is thereby considered adequately nutritious without fortification. However, whole grain flours have a high phytate content which inhibits absorption of iron, zinc, and calcium (4). Also, wheat’s naturally occurring vitamins may not be enough to have a desired public health impact. As consumers are encouraged to eat more whole grains, it may be necessary to consider fortification of these flours.