Iron stores and haemoglobin iron deficits in menstruating women. Calculations based on variations in iron requirements and bioavailability of dietaryiron

Background: Iron stores and haemoglobin iron deficits in menstruating women can be calculated from body iron losses and absorption of dietary iron usi ng recently developed methods. Objective: To examine iron balance (iron status) expressed as body iron sto res or haemoglobin iron deficites in menstruating women from amounts of iro n lost (iron requirements) and amounts of dietary iron absorbed. Calculatio ns are made both of stationary stales and of the rate of changes in iron st ores (iron Status) when any of the two main factors determining iron balanc e are changed. Design: The study is based on (1) previous and new equations describing rel ationships between iron absorption, iron requirements (losses), iron stores and/or haemoglobin deficits and (2) published data on iron requirements an d their variation in menstruating adult women. Results: Both iron stores and haemoglobin iron deficits are strongly relate d to iron requirements and absorption of dietary iron and follow the same e quations during states of iron repletion and iron deficiency. When, for exa mple, increasing or decreasing the bioavailability of the dietary iron, abo ut 90% of the change in iron stores will occur within 1 y. Conclusions: There are strong relationships between iron requirements, bioa vailability of dietary iron and amounts of stored iron. The observations th at a reduction in iron stores and a calculated de crease of haemoglobin iro n had the same increasing effect on iron absorption suggest that the contro l of iron absorption is mediated from a common cell, that may register both size of iron stores and hemoglobin iron deficit, eg the hepatocyte.