Submitted to: International Journal for Vitamin and Nutrition Research
Publication Type: Review Article
Publication Acceptance Date: May 18, 2005
Publication Date: November 1, 2005
Citation: Hunt, J.R. 2005. Dietary and physiological factors that affect absorption and bioavailability of iron. International Journal for Vitamin and Nutrition Research. 75(6):375-384. Technical Abstract: Iron deficiency, a global health problem, impairs reproductive performance, cognitive development, and work capacity. Addressing this problem will require improvements in dietary iron bioavailability. Knowledge of the molecular mechanisms of iron absorption is growing rapidly, with identification of mucosal iron transport and regulatory proteins. Both body iron status and dietary bioavailability substantially influence iron absorption, with minimal interaction between these two factors. Iron bioavailability can be regarded mainly as a characteristic of the diet, but comparisons between human studies of iron absorption require normalization for the iron status of the subjects. The dietary characteristics that enhance or inhibit iron absorption from foods have been sensitively and quantitatively determined in human studies employing iron isotopes. People with low iron status can substantially increase their iron absorption from diets with moderate to high bioavailability. But while iron supplementation and fortification trials can effectively increase blood indices of iron status, improvements in dietary bioavailability alone have had minimal influence on such indices within several weeks or months. Plentiful, varied diets are the ultimate resolution to iron deficiency. Without these, dietary bioavailability approaches to human iron deficiency likely will need to be augmented by dietary iron fortification.