Study Finds Need to Reevaluate Routine Iron Fortification of Infant Formulas
Iron-Deficiency Anemia was once a major problem in the United States, but has become much less common with the introduction of iron-fortified infant formulas and cereals within the past 30 years. But the amount of iron that infant formulas contain is still a matter of debate within the medical and research community. Some studies have shown that supplementing iron into the diet of a non-deficient child can actually do more harm than good, including the most recent trial published in the JAMA journal Archives of Pediatrics and Adolescent Medicine.
Iron deficiency remains the world’s single most common nutrient deficiency with about 25% of the world’s babies affected. Causes include insufficient iron in the diet and poor absorption of iron by the body. Poverty is often a contributing factor, because these families may not have adequate access to iron-rich foods.
Infants younger than 12 months are at risk for iron deficiency anemia because rapid growth also increases the need for the mineral. Most need to receive 8-10 mg or iron per day. Breastfed babies need less, because iron is absorbed 3 times better when it is in breast milk. But those solely on formula may be at risk for not receiving adequate levels, hence the reasoning for supplementation to commercially made infant formulas.
U.S. infant formulas typically come fortified with 12 mg/L of iron to prevent iron-deficiency anemia. Europe generally uses a lower amount.
In hopes of finding more answers to the question about the optimal amount of iron in infant formula, Dr. Betsy Lozoff, a behavioral pediatrician at the University of Michigan Health System and research professor at the University of Michigan Center for Human Growth and Development, led a 10-year study of 835 healthy, full-term infants living in urban areas around Santiago (Chile). The babies were randomized at 6 months of age to receive formula with or without iron. Less than 10% of the infants in the iron-fortified group met criteria for iron deficiency.
Overall, there were no statistically significant differences found in iron status at 10 years. Only one child was diagnosed with iron deficiency anemia.
Out of the original cohort, 473 children were included in the follow-up assessment which included measurements of IQ, spatial memory, arithmetic achievement, visual-motor integration (VMI), visual perception and motor functioning. Compared to the group that received the low-iron formula, the iron-fortified group scored lower on every outcome measured. Out of the seven tests administered, statistically-significant differences were seen for spatial memory and VMI.
Breaking down the iron-fortified group further, those children with the highest hemoglobin levels at 6 months of age had lower 10-year scores than those with the lowest hemoglobin levels indicating that those with sufficient iron stores had poorer outcomes when supplemented with the mineral.
“The high prevalence of iron deficiency in infancy has led to routine iron fortification of infant formula and foods in many countries,” says Dr. Lozoff. “These interventions help reduce iron-deficiency anemia and iron deficiency without anemia. However, the optimal amount of iron in such products, especially infant formula, is debated,” she says.
However, “this study indicates poorer long-term developmental outcome in infants with high hemoglobin concentrations who received formula fortified with iron at levels currently used in the United States. Optimal amounts of iron in infant formula warrant further study.”
B. Lozoff, M. Castillo, K. M. Clark, J. B. Smith. Iron-Fortified vs Low-Iron Infant Formula: Developmental Outcome at 10 Years. Archives of Pediatrics and Adolescent Medicine, 2011; DOI:10.1001/archpediatrics.2011.197
P. Christian. Iron in Infancy and Long-term Development. Archives of Pediatrics and Adolescent Medicine, 2011; DOI: 10.1001/archpediatrics.2011.203
University of Michigan (2008, May 5). Iron Supplements Might Harm Infants Who Have Enough, Study Suggests. ScienceDaily. Retrieved November 8, 2011
MedlinePlus (A service of the US National Library of Medicine and the National Institutes of Health): Iron Deficiency Anemia - Children