Adherence, safety, bioavailability, and acceptability of amaranth grain flatbread during pregnancy: evidence from a cluster randomized trial in Sidama region, Ethiopia

Maternal anemia is a major public health concern in Ethiopia. Nutrient-dense local foods like amaranth may improve iron status during pregnancy. This study evaluated adherence, safety, bioavailability, and acceptability of amaranth grain flatbread during pregnancy in Sidama region, Ethiopia. Between September 2024 and February 2025, a two-arm parallel cluster randomized controlled trial was carried out in the Hawela Lida district, Ethiopia. A total of 306 pregnant women (< 12 weeks gestation) were randomized to amaranth (n = 153) and maize flatbread (n = 153) for six months. Primary outcomes: haemoglobin concentration and iron deficiency anemia (IDA). Secondary outcomes: adherence, safety, bioavailability biomarkers, and acceptability. Blood samples were analyzed using HemoCue and ELISA. Mixed-effects models accounted for clustering and baseline covariates. Of 306 participants, 293 (95.8%) completed the study. The amaranth group had higher mean haemoglobin concentration (adjusted β = + 2.67, 95% CI: 2.41–2.91) and lower IDA (ARR = 0.47, 95% CI: 0.26–0.84) than controls. Adherence was higher in amaranth arm (AOR = 1.25, 95% CI: 1.08–1.44) and no serious adverse events occurred. Acceptability was greater in the intervention arm (AOR = 1.72, 95% CI: 1.21–2.46). Qualitative results supported quantitative findings, with participants reporting enthusiasm and readiness to continue consuming. Daily amaranth flatbread is safe, highly acceptable, and improves maternal iron status, supporting its integration into maternal nutrition programs in low-resource settings. ClinicalTrials.gov, NCT06536153, registered on July 30, 2024.