What do systematic reviews say?

Oral iron vs inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 402 participants
  Very low

Parenteral iron vs oral iron

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 769 participants
  Low

Intravenous iron vs oral iron

Intravenous iron therapy may leads to higher haemoglobin levels at end of preoperative treatment (g/dL) compared with oral iron therapy (low certainty).

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  MD 1.23 [0.8, 1.65]
  2 studies · 172 participants
  Low
• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found