Related Experiment Video
Updated: Jun 11, 2026

Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes
Published on: May 10, 2022
Iron intake and iron status in breastfed infants during the first year of life
Katharina Dube1, Jana Schwartz, Manfred J Mueller
1Research Institute of Child Nutrition, Rheinische Friedrich-Wilhelms University of Bonn, Heinstueck 11, D-44225 Dortmund, Germany.
Insights
Fully breastfed infants are at risk for iron deficiency. Early iron supplementation via complementary foods is recommended to prevent iron deficiency (ID) and iron deficiency anemia (IDA) in infants.
Area of Science:
- Pediatric Nutrition
- Infant Health
- Iron Metabolism
Background:
- Breast milk is low in iron, potentially increasing risk for iron deficiency in exclusively breastfed infants.
- This study examines iron status in breastfed infants compared to formula-fed infants.
Purpose of the Study:
- To assess iron status indicators in fully breastfed infants compared to formula-fed infants.
- To determine the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) in these groups during infancy.
Main Methods:
- Retrospective analysis of a randomized controlled trial comparing breastfed (BM) and formula-fed (F) infants.
- Iron intake and iron status indicators analyzed at 4, 7, and 10 months of age.
Main Results:
- Breastfed infants had low iron intake and higher rates of ID (21%) and IDA (up to 6%) by 7-10 months.
- Formula-fed infants maintained adequate iron status throughout the study period.
- No infant developed iron deficiency anemia at 4 months.
Conclusions:
- Fully breastfed infants are at significant risk for iron deficiency and anemia later in infancy.
- Early introduction of iron-rich complementary foods (4-6 months) is crucial for preventing ID and IDA.
Background & Aims:
Breastfed infants may be at particular risk for iron deficiency because breast milk is low in iron. In a secondary analysis of data from a complementary feeding trial, indicators of iron status were examined, with particular focus on the development of iron status in those infants who were fully breastfed during the first 4 months of life.
Methods:
In this retrospective analysis of data from a randomized controlled trial infants were stratified according to their predominant milk diet during the first 4 months of life, a subgroup of breastfed infants (group BM, n=53) were compared with a subgroup of infants fed (iron-fortified) formula (group F, n=23). Dietary iron intake and indicators of iron status were analysed at 4 months of age (during the full milk feeding period), and during the complementary feeding period at 7 and 10 months of age.
Results:
Iron intake was low in the BM group, ranging below the Dietary Reference Intakes throughout the complementary feeding period, with the (estimated) bioavailable iron intake only just achieving the reference requirements. At 4 months, iron deficiency (ID, Ferritin <12.0 ng/mL) was observed in 3 infants in the BM group and in 1 infant in the F group; no infant developed iron deficiency anaemia (IDA, ID and Hb <10.5 g/dl). At 7 and at 10 months of age, iron status was adequate in all infants of the F group. In the BM group, at 7 (10) months of age, ID was diagnosed in 10 (11) infants and IDA was found in 2 (1) infants.
Conclusions:
Healthy infants, fully breastfed at 4 months of age, demonstrated ID in about 21% and IDA in up to 6% during the second half of infancy while fed according to the paediatric dietary guidelines. This finding supports the recommendation that supplementation with bioavailable iron via complementary foods should be started early (4-6 months of age) in order to prevent iron deficiency during infancy.
Related Concept Videos
Development of Immunocompetence
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
Anatomy of the Intestines
Small Intestines
The small intestine is an ~7 meter-long tube with an inner diameter of just 2.5 cm. Since most nutrients are absorbed here, the inner lining of the small...
Development of the Oral Microbiota
Development of Human Microbiota
The Early Endosome: Endocytosis of Transferrin
Environmental Influences on Intelligence

