Iron consumed through groundwater is associated with iron status of women of reproductive age in rural Bangladesh

Background: Rates of iron deficiency (ID, plasma ferritin < 12 µg/l) and resultant anemia (IDA, ID plus low Hb) were very low among women of reproductive age (n=1198) participating in a field trial in rural Bangladesh from 2002 – 2006, both being < 7% at 1st and 3rd trimester and 3 months postpartum assessments. Intakes of iron sources (heme foods and supplements) were infrequent suggesting consumption of unconventional iron sources was enabling the maintenance of sufficient iron stores through pregnancy and lactation.

Methods: In 2008 during 2 follow-up examinations, 287 participants randomly selected from the original field trial were re-visited to explore the influence of exposure to groundwater, as a source of iron, on chronic iron status.

Results: Heme and iron supplement intake remained low (meat, fish, and poultry intakes (median (IQR)): 5 (3-9) times/wk, any supplement use ≤ 4% of participants). Iron deficiency was non-existent (n=222, median (IQR) plasma ferritin (µg/L) at follow-up: 66.8 (41.8, 100.4), 0% ID and IDA). Accounting for tubewell iron concentration (median (IQR): 16.5 mg/L (7.2, 28.3)) and daily tubewell water consumption (median (IQR): 2.6 L/day (2.1, 3.3)), participants (n=278) chronically consumed 42.3 mg iron/day (17.8, 71.8) through drinking water. Current iron status was significantly associated with amount of iron consumed daily through drinking groundwater (n=214, Spearman rho=0.34, p value<0.00).

Discussion: Natural groundwater iron consumed through drinking may provide a sustainable dietary source of iron. Funded by The Bill and Melinda Gates Foundation, Procter and Gamble, Inc, and USAID.