A mathematical model for the hemoglobin response to iron intake, based on iron absorption measurements from habitually consumed Indian meals.

BACKGROUND/OBJECTIVES: The prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) is high in India and appear unchanging over decades. To understand the persistence of these disorders, it is critical to measure iron (Fe) absorption from cereal-based Indian meals, its modulation by ID and the time-course of the response of hemoglobin (Hb) to Fe intake. SUBJESTS/METHODS: Fe absorption from rice-based meals was measured by the erythrocyte incorporation of the stable isotope label at 14 days in IDA (N=15) and Fe replete (IR) women (N=15). Hb level was used as surrogate for Fe status, and a response curve for Fe absorption versus the Hb level for a rice-based meal was constructed from measured data. This relationship was used as input for a mathematical model that examined the Hb response to different Fe intakes in normal and anemic women.

RESULTS

The mean fractional Fe absorption from a rice-based meal in IR and IDA women was 2.7% and 8.3%, respectively. The model predicted that Fe intakes between 20 and 55 mg/day in low-bioavailability diets would result in stable, non-anemic levels of Hb in women over a 1-year period.

CONCLUSION

This mathematical model suggests that with a Fe intake of 20-30 mg/day and a dietary bioavailability of 3-5%, Hb concentration would hover around 12 g/dl with a variability of 0.5 g/dl in pre-menopausal adult women.