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What’s the Harm in High-Iron Baby Formula?

New research shows iron-fortified formula may be harmful to nonanemic infants

When it comes to babies’ iron levels, how much is too much?

Iron is a critical nutrient for normal brain development and a common supplement in baby formula for infants 6 to 12 months of age. But in adults, excess iron in the brain has been associated with motor and cognitive impairments. Once accumulated, iron cannot be easily eliminated from the body.

In babies with iron deficiencies, high-iron formula is vital for preventing the effects of anemia. But if a baby shows satisfactory iron levels, could iron supplements be unnecessary or even harmful?

To explore this, an international team of researchers led by faculty at University of California San Diego School of Medicine conducted a long-term study monitoring 562 healthy infants who were randomly assigned to an iron-fortified formula or a no-added-iron formula from the ages of 6 to 12 months. This was the first study to gauge the effects of iron supplementation in nonanemic infants.

Sixteen years later, the results showed that adolescents who consumed the high-iron formula as infants had poorer problem-solving, information processing and quantitative reasoning skills and worse visual-motor integration than adolescents who were fed regular formula. In fact, the more iron-fortified formula a child consumed in infancy, the lower their arithmetic and calculating abilities were in adolescence.

The new findings suggest that both low and high levels of iron can be detrimental to an infant’s brain development. First author Patricia East, PhD, professor at UC San Diego School of Medicine, recommends closely monitoring an infant’s iron status before deciding whether or not to supplement their iron intake.

Read more about the study, published in Nutritional Neuroscience.

— Nicole Mlynaryk