The side-effects of different doses of iron sulfate on women of reproductive age: a randomized double-blind, placebo-controlled study

Abstract

OBJECTIVES: to identify side effects of the use of different doses of iron sulfate (IS). METHODS: an eight-week randomized, double blind, placebo-controlled trial was carried out involving 727 women aged 20-49 years between October 2005 and October 2006. The women were randomly allocated into eight groups with daily or twice-weekly doses administered during or in between meals. The information was obtained by weekly telephone contact. Analysis involved comparison of the proportion of complaints from the different groups. RESULTS: of 726 women initially selected, 74.2% completed eight weeks of follow up. In the regimens containing IS 95.2% of women reported gastrointestinal complaints. More complaints were reported for daily doses than for ones (p <0.001). Those taken between meals were associated with more nausea than those taken during meals (p<0.001). Of the 95 women who withdrew from the experiment, 88.4% belonged to the IS group and diarrhea was the main complaint (29.8%). CONCLUSIONS: the use of iron sulfate was associated with gastrointestinal side effects, especially when taken daily and diarrhea was the main complaint associated with IS.