Comparative Study of Ferrous Fumarate, Ferrous Ascorbate, and Polysaccharide Iron for Treating Iron Deficiency Anemia in Adults

Iron deficiency anemia (IDA) is a highly prevalent condition encountered in clinical practice and represents a major global health concern, affecting an estimated 1.92 billion individuals worldwide. Despite its prevalence and the availability of various oral iron formulations with wide cost variations, comparative data on their efficacy and tolerability remain limited. This randomized, open-label trial conducted across two centres evaluated the efficacy, tolerability, and adherence of three oral iron supplements in improving hemoglobin and ferritin levels in adults with IDA. The study compared ferrous fumarate (Eurofer, 100 mg elemental iron, $15.87 for 90 tablets), ferrous ascorbate (EBMfer, 100 mg elemental iron, $68.97 for 90 tablets), and polysaccharide iron (FeraMAX, 150 mg elemental iron, $77.97 for 90 tablets). A total of 111 participants aged ≥18 years were randomly assigned into one of three treatment groups and monitored over a 12-week period. Both ferrous fumarate (p=0.001) and ferrous ascorbate (p<0.001) demonstrated significantly greater hemoglobin and ferritin levels compared to polysaccharide iron. Specifically, ferrous fumarate led to mean increases in hemoglobin and ferritin of 11.59 g/L (95% confidence interval [CI]: 7.87–15.3, standard deviation [SD]: 10.7) and 19.21 µg/L (95% CI: 7.82–28.6, SD: 29.8), respectively. Ferrous ascorbate showed mean increases in hemoglobin and ferritin levels of 17.14 g/L (95% CI: 13.5–20.8, SD: 10.7) and 23.51 µg/L (95% CI: 16.5–30.5, SD: 20.3), respectively. Polysaccharide iron showed mean increases in hemoglobin and ferritin of 3.56 g/L (95% CI: -0.06–7.18, SD: 10.4) and 3.21 µg/L (95% CI: -0.07–6.48, SD: 9.39), respectively. Adverse events occurred more frequently with ferrous fumarate (13 events) compared with ferrous ascorbate (8 events) and polysaccharide iron (6 events). The most commonly reported side effects across all groups were constipation and bloating, well-documented side effects of iron supplements. These findings demonstrate that ferrous fumarate and ferrous ascorbate significantly outperformed polysaccharide iron in improving hemoglobin and ferritin levels. Given its lower cost and comparable efficacy, ferrous fumarate may be the most cost-effective option and warrants consideration in updates to Canadian treatment guidelines.