RESUMO
BACKGROUND: Limited evidence supports the efficacy of iron-rich foods (IRFs) in improving iron status during pregnancy. OBJECTIVES: The study aims to evaluate the effect of IRFs on iron status and biomarkers of iron metabolism in the third trimester of pregnancy. METHODS: A total of 240 pregnant women at 11-13 wk of gestation without iron-deficiency anemia (IDA) in South China were recruited to this single-blind clinical trial [non-IDA referred to both hemoglobin (Hb) ≥110g/L and serum ferritin (SF) ≥15ng/mL], randomly assigned to 1) control, 2) IRFs containing 20 mg iron/d (IRF-20), or 3) IRFs containing 40 mg iron/d (IRF-40). The IRFs were consumed 3 days a week, including pork liver, chicken/duck blood, soybean, and agaric. The IRFs started at recruitment and ended in the predelivery room. Primary outcome included anemia (Hb <110 g/L), iron deficiency (ID, definition 1: SF <15 ng/mL; definition 2: SF <12 ng/mL), and IDA (ID and Hb <110 g/L). Secondary outcome was plasma Hb and iron indices, including SF, serum hepcidin, and iron. RESULTS: All participants who completed the trial with full data (n = 170) were included in the analysis. At the endline, both intervention groups showed lower ID and IDA rates than control. Specifically, IRF-40 showed a lower ID (SF <12 ng/mL) rate than control (9.0% compared with 22.8%, P = 0.022). For IDA by definition 1, the incidence in IRF-40 was lower than that in control (1.9% compared with 8.9%, P = 0.045). For IDA by definition 2, the incidence in IRF-20 was lower than that in control (3.9% compared with 17.9%, P = 0.049). Moreover, IRF-20 showed higher SF concentrations than control (P = 0.039). No effects of IRFs on anemia (P = 0.856), plasma Hb (P = 0.697), serum hepcidin (P = 0.311), and iron (P = 0.253) concentrations were observed. The assessed iron intakes were 22.2 mg/d in IRF-20 and 25.0 mg/d in IRF-40, respectively. CONCLUSIONS: Antenatal IRFs reduce the risk of ID and IDA in late pregnancy, although the present results are inadequate to confirm an ideal dosage (No. ChiCTR1800017574).