According to a recent study, maternal iron supplementation may increase the risk of celiac disease in children (Clin Gastroenterol Hepatol 2014; 12: 624-31).
Using the Norwegian Mother and Child cohort study (1999-2008) which included data for 78,846 children, the authors analyzed the risk of developing celiac disease by examining prospectively collected questionnaires regarding iron supplements, diet, and anemia. Questionnaires were obtained 3 times during pregnancy, then at age 18 months, 6 years, 7 years and 8 years.
Key Results:
- 4.65 of 1000 children whose mothers took iron supplements while pregnant developed celiac disease compared to 3.15 of 1000 whose mothers did not.
- After adjustment for multiple variables, the OR was 1.33 for children developing celiac disease if their mother took iron supplementation during pregnancy.
- The authors note that maternal anemia was not associated with celiac disease in offspring nor was iron supplementation in childhood.
While these findings are intriguing, the associated editorial (pg 632-35) notes that unmeasured confounding variables could explain the findings. For example, undiagnosed maternal celiac disease which could increase the likelihood of iron exposure could increase the risk of celiac disease in the offspring and account for the increased association with iron supplementation.
Take-home message (from the editorial): “it is premature to argue that iron supplementation during pregnancy should be avoided in individuals with celiac disease…the observed effect (an absolute risk increase of 0.15%) is modest in magnitude. This exposure is not driving the slow, ongoing epidemic of celiac disease.”
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