Thalassemia carrier status and groundwater iron: Implication for iron supplementation program for children in Bangladesh.

Background: Thalassemia, a congenital disorder of hemoglobin synthesis is characterized by low hemoglobin and high iron status, is prevalent in Bangladesh. Iron, consumed through drinking groundwater also increases the population iron status in Bangladesh. The study examined the effect of iron containing micronutrient powder (MNP) on the hemoglobin and ferritin status in Bangladeshi children with thalassemia and their non-thalassemia peers exposed to a high concentration of iron from drinking groundwater. Design and methods: Three hundred twenty-seven children aged 2-5 years were recruited for an MNP efficacy trial. A sub sample (n = 222) were screened for thalassemia. Hemoglobin and ferritin levels were measured in children with and without thalassemia. Intake of iron from the key sources-diet, groundwater and MNP was measured. Mann Whitney and t-test were employed to compare the groups. Results: Hemoglobin concentration of the children with thalassemia at the endpoint remained unchanged relative to the baseline; 11.56 ± 0.59 g/dL (Endpoint) versus 11.6 ± 0.54 g/dL (Baseline), p = 0.83. In children without thalassemia hemoglobin tended to increase; 12.54 ± 0.72 g/dL (Endpoint) versus 12.41 ± 0.72 g/dL (baseline), p = 0.06. Baseline reserve of body iron was significantly (p = 0.03) higher in thalassemia carriers (594 gm) compared to their non-carrier peers (558 gm). The increase of the infection-adjusted ferritin from baseline to the endpoint was 7.37% (p = 0.7) and 10.17% (p = 0.009) in the carrier and non-carrier groups respectively. Conclusions: In Bangladesh, the coexistence of thalassemia and the exposure to a high concentration of iron from drinking groundwater renders anemia prevention program with a low iron MNP potentially lesser hazardous to the thalassemia carriers.