Iron supplements intake acutely elevates hepcidin levels, decreasing the subsequent iron absorption with lower dosages and alternate day supplementation maximizing absorption.
In the methodology, a total of 54 nonanemic young women having plasma ferritin ≤20 µg/L were selected. There were two studies: the first study had 25 participants who were given varying doses of iron ranging from 40mg to 240mg at 8:00 am while fasting for one or two consecutive days. In the second study, 16 participants were given similar iron doses. A third study involving 13 participants entailed ingestion of three 60mg Fe doses within a span of 24 hours.
In the results discussion, it was found that doses above 60mg led to a rise in serum hepcidin levels after 24 hours, causing a decline in fractional iron absorption by 35% to 45%. As the dosage increased, absorption fraction decreased but absolute absorption increased. For instance, a sixfold increase in iron dose resulted only in a threefold increase in amount of iron absorbed. Furthermore, the total iron absorbed from three doses was not considerably greater than from two morning doses.
