Which child is at greatest risk for iron deficiency anemia?

• A. 4 month-old term infant exclusively fed human milk
• B. 4 month corrected gestational age, former preemie on a transitional formula
• C. 17 month-old "picky eater"
• D. 10 month-old switched from formula to whole milk

Answer: (D)

Iron intake during infancy is crucial because daily iron needs rise as infants grow, and iron-rich sources become essential after the first few months. Whole cow’s milk provides little iron and can displace iron-containing foods, so introducing it before 12 months dramatically increases the risk of iron deficiency anemia. The child who switched from formula to whole milk is therefore at greatest risk, since formula is typically iron-fortified and supports adequate iron intake, whereas whole milk does not and can crowd out other iron sources. The other scenarios carry risk as well—exclusive breastfeeding without iron supplementation can lead to iron deficiency as stores dwindle around 4–6 months, and a former preemie on transitional formula may still be getting iron, while a picky eater may have limited iron intake—but none rise to the same level of immediate risk as early cow’s-milk introduction.