The primary care nurse practitioner performs a well-baby examination on a 4-month-old infant who is exclusively breastfed, and whose mother plans to introduce only small amounts of fruits and vegetables in addition to breastfeeding. To ensure that the infant receives adequate iron, what will the practitioner recommend?

Choice A reason: Routine monitoring of hemoglobin and hematocrit is not sufficient to prevent iron deficiency. It is a reactive measure and does not address the need for proactive supplementation in exclusively breastfed infants. Choice B reason: A dose of 3 mg/kg/day is excessive for routine prophylaxis in healthy, term, breastfed infants. This dosage is typically reserved for treatment of confirmed iron-deficiency anemia. Choice C reason: Iron-fortified formula is an alternative for infants not exclusively breastfed. However, in this case, the mother plans to continue breastfeeding, so supplementation is preferred over formula substitution. Choice D reason: The recommended prophylactic dose for exclusively breastfed infants starting at 4 months is 1 mg/kg/day of elemental iron until iron-rich complementary foods (like cereals) are introduced. This ensures adequate iron stores during a critical growth period.