What Is the Best Test for Iron Deficiency?

In Reply.— Dine raises a very important question which is continuously posed by the pediatrician in practice-what is the best (simple, inexpensive, and sensitive) test to determine whether an infant or child has iron deficiency? If there were an easy answer, this question would not be repeatedly asked. No single laboratory test is sufficiently sensitive and specific to detect all patients with iron deficiency or even iron deficiency anemia.1 For example, it has been demonstrated that close to one third of infants with hemoglobin in the low-normal range (11.0 to 11.4 g/dL) will display a significant increase in hemoglobin following a therapeutic trial of iron.2