Efficacy and trial effectiveness of weekly and daily iron supplementation among pregnant women in rural Bangladesh: disentangling the issues

Background According to our current understanding, iron absorption with weekly iron supplements is not higher than that with daily supplements (ie, there is no mucosal block). However, community-based trials have repeatedly shown that a weekly regimen is as effective as a daily one. Furthermore, when differences in absorption are found, they are commonly smaller than would be expected on the basis of differences in the amount of iron provided. The possibility of differential compliance between the regimens needs to be evaluated to explain these findings. Objective Taking compliance into account, we compared the efficacy and trial effectiveness of weekly and daily iron supplementation during pregnancy. Design In Bangladesh, 50 antenatal centers were randomly assigned to prescribe either 2 doses of…