Iron is an essential trace metal in the human diet playing a crucial role in a number of physiological and biochemical functions. Iron homeostasis is maintained by matching dietary absorption to the body's iron requirements (for haemoglobin synthesis, cellular metabolism etc). However, diseases associated with imbalances in body iron status are relatively common - up to 2 billion people worldwide suffer from iron deficiency anaemia while 1:10 people of northern European decent carry a defect in the hfe gene that predisposes them to the iron loading disease haemochromatosis. Clearly therefore body iron status needs to be carefully controlled to maintain optimum human health. Work in my laboratory investigates both the dietary and humoral regulation of duodenal iron absorption with a particular emphasis on diet-gene interactions.