Randomized controlled trial of twice-daily versus alternate-day oral iron therapy in the treatment of iron-deficiency anemia

Ann Hematol. 2020 Jan;99(1):57-63. doi: 10.1007/s00277-019-03871-z. Epub 2019 Dec 6.


Recent studies in iron-depleted women have challenged the current approach of treating iron-deficiency anemia (IDA) with oral iron in divided daily doses. Alternate day dosing leads to more fractional absorption of iron. In this randomized controlled trial, we looked at the efficacy and safety of alternate-day (AD) versus twice-daily (BD) oral iron in all severity of IDA. Total of 62 patients were randomized, 31 patients in BD arm received 60 mg elemental iron twice daily while 31 patients in AD arm received 120 mg iron on alternate days. The primary endpoint of 2 g/dl rise in hemoglobin was met in significantly more patients in the BD arm at 3 weeks (32.3% vs. 6.5%, p < 0.0001) and 6 weeks (58% vs. 35.5%, p = 0.001). There was a significant rise in the median hemoglobin at 3 (1.6 vs. 1.1, p = 0.02) and 6 weeks (2.9 vs. 2.0 g/dl, p = 0.03) in the BD arm. However, the median hemoglobin rise in the AD arm at 6 weeks was not significantly different than the BD arm at 3 weeks. Alternate-day dosing for 6 weeks and twice-daily dosing for 3 weeks resulted in the provision of the same total amount of iron. There were more reports of nausea in the BD arm (p = 0.03). In conclusion, the choice of twice-daily or alternate-day oral iron therapy should depend on the severity of anemia, the rapidity of response desired, and patient preference to either regimen due to adverse events. Trial Registration: CTRI reg. no. CTRI/2018/07/015106 http://ctri.nic.in/Clinicaltrials/login.php.

Keywords: Alternate day; Daily; Hepcidin; Iron-deficiency anemia; Oral iron.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Aged
  • Anemia, Iron-Deficiency / blood
  • Anemia, Iron-Deficiency / drug therapy*
  • Female
  • Hemoglobins / metabolism
  • Humans
  • Iron / administration & dosage*
  • Iron / blood
  • Male
  • Middle Aged
  • Time Factors


  • Hemoglobins
  • Iron