Current methods for estimating dietary iron bioavailability do not work inChina

Three current equations for estimating iron bioavailability were evaluated, and adjustments were proposed that would allow us to most effectively stud y iron bioavailability in China. Dietary intake data were obtained from 24- h dietary recalls taken over three consecutive days as part of the third Ch inese National Nutrition Survey. Hemoglobin status was measured for 42,606 Chinese adults aged 18-60 y. The mean iron intake was 24.4 mg per capita pe r day, which was 177% of the Chinese RDA (209% of U.S. RDA). About 18% of t he sample was classified as being anemic, indicating a large iron deficienc y anemia and iron bioavailability problem in China. A number of methods pro posed by World Health Organization and U.S. scholars were examined for adju sting iron bioavailability. Even the methods that consider several iron enh ancers and inhibitors did not work adequately for the Chinese diet. The sta tistical assessment of the fit between iron bioavailability and hemoglobin status provided direction for adjusting the best of these predictive equati ons. We propose a new predictive approach for iron bioavailability which is more predictive of Chinese iron status. Consideration of additional dietar y elements such as rice and bean consumption patterns are important. Our fi ndings provide insight into additional factors which may influence iron bio availability as well as possible improved methods for estimating the combin ed effect of multiple dietary factors on iron bioavailability, particularly in a vegetarian diet.