The association between diagnosed food allergies and health outcomes in children.

The outcomes were vitamin B12 levels (with deficiency defined as less than 300 nanograms per liter), hemoglobin levels (with anemia defined as less than 11 grams per deciliter), eosinophil counts (higher levels can indicate a higher risk of allergic conditions), breastfeeding duration, formula use, child delivery method (i.e., cesarean or vaginal), child weight percentile, child height percentile, and family history of atopy (having conditions like eczema or asthma).

Food allergies and the risk of vitamin B12 deficiency in children Original paper