Iron deficiency anemia (IDA) is still a major global health problem. The prevalence was highest among children under five years, 39.7%, with the most contributing cause being dietary iron deficiency (ID). Reticulocyte hemoglobin equivalent (Ret-He) assesses the amount of hemoglobin in reticulocytes. Ret-He is an easy, inexpensive, and applicable diagnostic parameter of iron deficiency. This study aims to determine the role of Ret-He as a diagnostic parameter of ID and IDA in infants 1-4 months old.

Material and methods:
The study was conducted prospectively at 10 Community Health Centers in Banjarbaru, South Kalimantan, from August 2020 to August 2021. Total 403 infants aged 1, 2, 3, and 4 months met the inclusion and exclusion criteria. Venous blood samples were checked for Ret-He, complete blood count, and peripheral blood smears.

The incidence of ID and IDA in infants 1-4 months were 10,9% and 58,6%. Ret-He cut-off values for iron deficiency and IDA at 1, 2, 3 and 4 months were 22,25 pg, 20,3 pg, 19,05 pg and 17,55 pg; with sensitivity 7,8%, 2,5%, 7,4%, 8,2%; specificity 94,4%, 95,0%, 96,9%, 98,1%; positive predictive value 85,7%, 66,7%, 83,3%, 80,0%, and negative predictive value 18,1%, 19,6%, 33,0%, 53,6%.

Ret-He can detect iron deficiency and IDA in 1-4 months baby with high specificity and positive predictive value.