Effect of food on iron absorption in patients with iron deficiency anemia treated with ferric citrate hydrate

Iron absorption after the administration of oral iron preparations following a meal is generally reduced compared with fasting. The aim of this study was to investigate the effect of food on iron absorption following ferric citrate hydrate administration in patients with iron deficiency anemia. A randomized, open-label, two-cohort, two-period, single-dose crossover study was conducted to assess the effect of food on iron absorption when 500 mg ferric citrate hydrate (approximately 120 mg of ferric iron) was administered under fasted and fed (immediately after a meal) conditions. Twelve patients aged 20-45 years with iron deficiency anemia (hemoglobin: male 8.0-13.0 g/dL, female 8.0-12.0 g/dL; serum ferritin < 12 ng/mL; transferrin saturation ≤ 16%), participated. The maximum serum iron concentration change was defined as ΔC_max, and the area under the serum iron concentration change versus time curve from baseline to 24 h after administration as ΔAUC_0-24. Serum iron levels increased regardless of fasting or fed conditions, and the ΔC_max and ΔAUC_0-24 values were 39% and 29% higher, respectively, under fed versus fasting conditions. No adverse events were reported. In conclusion, food had no notable effect on iron absorption following ferric citrate hydrate administration in patients with iron deficiency anemia.