Stable iron isotope techniques are essential for evaluating iron kinetics from oral supplements and fortificants, as well as for studying the effects of diseases and genetic disorders on iron absorption and excretion.

The appearance of a stable iron isotope in plasma after oral administration can be used to immediately assess the rate, quantity, and pattern of iron absorption. In contrast, the erythrocyte iron incorporation method measures both the absorption and subsequent utilization of iron by erythrocytes, measured 14 days after administration.

The iron isotope dilution method employs naturally occurring iron as a tracer, which dilutes an enriched isotopic signature previously introduced and equilibrated with the body’s iron stores. This innovative new technique enables long-term studies of iron absorption, loss, and gain.