Patients with iron deficiency anemia (IDA) are given vitamin C with oral iron supplements. But their efficacy in alleviating the deficiency of iron is not certain. This study aims to assess the safety of oral iron supplements with vitamin C, along with comparing the equivalence of oral iron supplements with or without vitamin C.

This open-label, single-center, equivalence randomized clinical trial included a total of 440 patients with newly diagnosed IDA. The patients were randomly assigned in a 1:1 ratio to receive oral iron supplements plus vitamin C (n=220) or oral iron supplements alone (n=220). The primary outcome of the study was the change in hemoglobin level from baseline to 2 weeks of treatment.

A total of 432 patients of 440 patients initially included completed the trial (98.2%). At a two-week follow-up, the mean change in hemoglobin level was 2.00 g/dL in the oral iron supplements-vitamin C group and 1.84 g/dL in the iron supplements-only group. The criterion for equivalence was, therefore, met. The mean change from baseline in serum ferritin level was 35.15 in the combination group and 34.48 in the supplement-only group.

The research concluded that oral supplements alone had equivalent efficacy to iron supplements plus vitamin C in patients with IDA.