Intake of iron through groundwater and iron status of women in rural Bangladesh

Background. Groundwater has long provided domestic water needs in Bangladesh. This water source is known to have elevated and variable dissolved iron. The objective of this thesis is to estimate the influence of iron consumed through groundwater on iron status of women in rural Bangladesh and to investigate the epidemiology of anemia under conditions of apparent iron sufficiency with a focus on the possible roles of nutritional status, thalassemia, and groundwater arsenic.;Methods. Subjects for this study were 321 women who participated 2 to 5 years earlier in a vitamin A supplementation field trial. Women were visited during two seasons in 2008 to collect information on groundwater use from local tubewells, 7-day dietary intakes, including rice consumption in the previous 24 hours, and recent morbidity. Anthropometric status (height, weight, mid-upper arm circumference, and tricipital and subscapular skinfolds) was measured in round 1. Blood was collected in round 2 to assess iron (hemoglobin (Hb), plasma ferritin, and transferrin receptor), infection (C-reactive protein >5.0 mg/L), and thalassemia (beta thalassemia, Hb E) status. Water from all tubewells was analyzed in the field in both rounds for iron and arsenic concentration, pH, temperature, and oxidation reduction potential.;Results. Iron deficiency (ferritin < 12 microg/L) was nonexistent (0%) although anemia (Hb < 120 g/L in non-pregnant women) was common (57%). Groundwater iron was elevated (median (IQR) mg/L: 16.7 (7.2, 28.3)) contributing a median (IQR) daily iron intake of 41.6 (16.1, 71.4) mg/day. For every 10 mg/day increase in iron intake through water, plasma ferritin increased 6% (3%, 8%) in adjusted analyses. Thalassemia (27% prevalent) was associated with 2.54 (95% CI: 1.28, 5.08, p<0.01) higher odds of anemia in adjusted analyses but was unassociated with iron status (p=0.35). Low body mass index (< 18.5 kg/m2) and parity (≥2 offspring vs 1) were associated with increased odds of anemia (odds ratio (95% CI): 1.98 (1.09, 3.61), 2.64 (1.22, 5.73), respectively).;Conclusion. Groundwater provides a currently underappreciated dietary source of iron; the consumption of which may improve human iron status. Iron intake through groundwater should be included in dietary assessments in environments where it is used for drinking purposes.