Iron is an essential mineral that plays a vital role in numerous essential biochemical pathways. The bulk of ingested iron is excreted in the faeces.
Iron is not actively excreted from the body in urine or in the intestines. Iron is only lost with cells from the skin and the interior surfaces of the body – intestines, urinary tract and airways.
In normal adult male, daily iron losses are approximately between 0.9 and 1.0 mg/d (12 to 14 ug/kg/day). Most of these losses are via the gastrointestinal tract, with about 0.45 due to blood loss, which occurs even in healthy individual.
About 0.2 to 0.3 mg iron is lost by desquamated of surface cells from the skin. Urinary excretion is so small as to be negligible with means values of approximately 0.1 mg or less per day.
Under normal condition, the largest loss of iron is through bleeding in menstruating women; although considerably greater than other channel, these iron losses vary widely from individual to individual.
The mean loss is estimated to be between 0.6 and 0.7 mg/day, which translates into a loss of 17.5 mg iron per period.
The studies of the loss of radioisotope iron by men living in several countries suggest that the combined losses by all routes are of the order of 1 mg per day or less.
A storage pool maintains the remaining 25% in a form that is readily available for use if metabolically active iron is depleted for any reason. It is approximately 10 mg/kg in men and around 5 mg/kg in menstruating women.
Excretion of iron from human body
