Alternate day versus daily oral iron for treatment of iron deficiency anemia: a randomized controlled trial

Oral iron is the mainstay of treating iron deficiency anemia. Recent studies indicate better fractional iron absorption with alternate day supplementation. However, the optimal supplementation strategy is unclear. We compared effectiveness of daily versus alternate day supplementation of oral iron for treatment of iron deficiency anemia. This double blind, active control, randomized controlled trial was conducted on two hundred adults having hemoglobin 10 g/dL or less with microcytic hypochromic anemia and/or serum ferritin below 50 ng/mL. They were randomized to receive either two Ferrous sulfate tablets containing 60 mg elemental iron (120 mg total) on alternate days or single tablet of 60 mg elemental iron daily for 8 weeks. Primary outcome was mean change in hemoglobin at week 8 from baseline. Mean hemoglobin was 6.53 (± 1.89) and 6.68 (± 1.89) g/dL in the alternate day and daily arms respectively. Mean change in hemoglobin was + 1.05 ± 1.34 g/dL in alternate day arm and + 1.36 ± 1.51 g/dL in daily arm (p = 0.47) at week 8. There were no statistically significant differences between the arms with respect to any secondary outcome. There is no significant difference between alternate day and daily iron administration in improving hemoglobin. Randomized controlled trials enrolling more participants for longer periods of supplementation and evaluating clinically relevant outcomes like change in hemoglobin may be useful in identifying the ideal dosing strategy.Trial Registration: Clinical Trial Registry of India (CTRI/2019/01/017169).