Intestinal regulation of body iron.

A significant proportion of the world's population suffers from iron deficiency or iron overload. These disorders arise primarily from defects in the gastrointestinal absorption of iron. The intestinal mucosal cell plays a key role in this process because it lies at the interface between the gastrointestinal lumen which supplies its iron and body compartments which control its behaviour. The concentration of mucosal ferritin is closely linked to absorption, but it is still not clear whether it plays an active or a passive role. Transferrin also has been detected in the mucosal cell, but firm evidence that it participates in the absorptive process is lacking. Deficiencies in the luminal phase are responsible for the high global prevalence of iron deficiency which is predominantly dietary in origin. Much information has accumulated in recent years on dietary factors that enhance or impair iron absorption but their quantitative importance as determinants of iron status remains to be determined.