Iron deficiency is prevalent worldwide, and iron supplementation is a promising strategy to address iron needs of the body. However, traditional oral supplements such as ferrous sulfate, ferrous succinate, and ferrous gluconate are absorbed in the form of ferrous ions, leading to lipid peroxidation and side effects due to other reasons. In recent years, saccharide-iron (III) complexes (SICs) as novel iron supplements have aroused attention for the high iron absorption rate and no gastrointestinal irritation at oral doses. In addition, research on the biological activities of SICs revealed that they also exhibited good abilities in treating anemia, eliminating free radicals, and regulating the immune response. This review focused on the preparation, structural characterization, and bioactivities of these new iron supplements, as promising candidates for the prevention and treatment of iron deficiency.