Amino acid chelated iron (bisglycinate chelate iron, Ferrochel) has been developed and used as a food fortifier to prevent and treat iron deficiency anemia. However, its long-term use has not been described and reports of iron overload are unavailable. We report a case of a mother and daughter who were diagnosed with iron overload based on blood sampling. Serum analysis revealed elevated ferritin levels and increased transferrin saturation (TSAT). MRI of the daughter showed iron accumulation in the liver, spleen, and bone marrow with normal inflammatory response and no findings suggestive of collagen disease or tumor, and she was diagnosed with secondary iron overload due to oral administration of an amino acid chelated iron preparation. After discontinuing over-the-counter medications and approximately two years of phlebotomy, the women showed a trend toward improvement in their hematologic profiles. Although amino acid chelated iron supplements can be easily administered without side effects such as nausea, ferritin levels should be checked if they are administered for more than a year. Even asymptomatic patients may suffer from iron overload, which can be very dangerous if left untreated. Therefore, amino acid chelated iron should be considered as medicine rather than as a supplement, and immediate action is needed in these cases. This report highlights the importance of careful medication review of over-the-counter amino acid chelated iron supplements.