Figure 1. Box plot graph comparing sleep duration* in infants with and without iron deficiency anemia².

*Sleep duration refers to the average time (hours) at 3, 6, and 12 months of age; ^†Anemia groups were defined as follows: with anemia group: hemoglobin <11 g/dL at birth and/or at 6 months of age and without anemia group: hemoglobin ≥11 g/dL at birth and at 6 months of age. p-value (0.02) is derived from the Student’s t-test.