The Relationship between Marrow Iron Stores, Plasma Ferritin Concentrations and Iron Absorption

The percentage absorption from a 3 mg dose of ferrous iron was measured in 50 subjects with iron stores that varied over a wide range. Iron status was assessed by a number of measurements, including the haemoglobin concentration, the plasma iron concentration, the total iron‐binding capacity, the plasma ferritin concentration and the concentration of non‐haem iron in the bone marrow. There were good inverse correlations between the log percentage iron absorption and both the log marrow non‐haem iron concentration (r —0.94; P < 0.001) and the log plasma ferritin concentration (r —0.78; P < 0.001). In addition, there was a positive correlation between the marrow non‐haem iron concentration and the plasma ferritin concentration (r +0.84; P <0.001). These results suggest that reticuloendothelial iron stores represent an important determinant of iron absorption and that their size can be guaged from the plasma ferritin concentration. © Munksgaard 1979