Iron deficiency is more common in babies who were breast-fed longest

THE QUESTION Though breast-feeding promises a host of benefits for babies, might it also harbor risks, such as an increased chance of being iron-deficient?

THIS STUDY analyzed data on 1,647 healthy children who were about 3 years old. Nearly all had been breast-fed at some point, either exclusively or along with other fluids and foods — most for about 10 months and 27 percent for more than a year. Blood tests showed that about 9 percent were iron-deficient. The longer babies had been breast-fed, the more likely they were to have iron deficiency, with the risk increasing by 5 percent for each additional month of breast-feeding. Children who had been breast-fed for a year or more were 70 percent more likely to be iron-deficient than were children breast-fed for less than a year.

WHO MAY BE AFFECTED? Children who were breast-fed. Recommendations vary on how long a baby should be breast-fed. The American Academy of Pediatrics suggests that it extend beyond the child’s first birthday, and the U.S. Surgeon General and the World Health Organization urge exclusive breast-feeding for up to six months, with WHO also recommending that other foods be added but that breast-feeding continue for up to two years or more.

CAVEATS Data on breast-feeding duration came from the mothers’ responses on questionnaires. One of the study’s nine primary authors had received fees from several pharmaceutical companies that make iron supplements.

FIND THIS STUDY April 15 online issue of Pediatrics.

LEARN MORE ABOUT breast-feeding at and (Click on “For Patients” and scroll to “Labor, Delivery and Postpartum Care.”)

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.