Iron supplementation does not affect mucus production.

<p>Periodic acid-Schiff (PAS)-stained formalin-fixed, paraffin-embedded lung sections show allergen-induced goblet cell differentiation in the large airways of mice on both 8 ppm (<b>A</b> = saline-challenged, <b>B</b> = OVA-challenged) and 200 ppm diets (<b>C</b> = saline-challenged, <b>D</b> = OVA-challenged). Expression of Muc5AC mRNA in the lungs was similar for both diet groups (<b>E</b>).