A new mother notices that her 6-month-old son has a yellow-orange complexion. Fearful that the child may have jaundice (a condition caused by bilirubin, a toxic yellow-orange pigment produced during...

A new mother notices that her 6-month-old son has a yellow-orange complexion. Fearful that the child may have jaundice (a condition caused by bilirubin, a toxic yellow-orange pigment produced during the destruction of red blood cells), she takes him to her pediatrician. After examining the child, the pediatrician declares him perfectly healthy and advises the mother to watch the child’s diet. Why?