Background: Iron deficiency, which remains the most common cause of anemia, affects at least a third of the world’s population. Iron supplementation is widely used to treat IDA in children. However, there were limitations in the therapeutic trials, and the trials have not been systematically reviewed. Objectives: To assess the limitations of the trials about iron supplementation for IDA in children. Methods: We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, et al. Randomized controlled trials (RCTs) comparing different forms of iron supplementation to placebo, or other current regimens used to treat IDA, and comparisons between different forms of iron supplementation were included and analyzed. Results: Sixteen claimed RCTs were identified, of which only two described randomization methods, two mentioned double blindness without details, three described identical placebo used, and none mentioned allocation concealment. Iron supplementation showed some benefits for IDA in children. The methodological quality of RCTs might be poor in several aspects: 1. compared to prevention and therapeutic trials for general anemia, the number of trials investigating iron therapy for IDA specifically was much smaller; 2. some claimed RCTs were found to perform false randomization by telephone interviewing the original authors; 3. pooled analysis was not performed due to diversity of iron forms, administration ways and dosage; 4. few studies performed health economic analysis (important issue for developing countries where IDA is prevalent), adverse effects and health related life quality; 5. a large proportion of studies did not perform strict quality control on items such as sample size calculating and inclusion criteria explanation; 6. some potential RCTs were unable to be assessed owing to the difficulty to obtain full texts in China. Conclusions: High quality RCTs are stilled needed for assessing the therapeutic effects, adverse events, health economic outcomes and health related life quality of iron therapy for IDA specifically. Besides, we suggest investigating the original authors of articles in order to avoid false information influencing the quality of systematic reviews.