Hen's egg allergy is a risk factor for zinc deficiency.

Background: Insufficient zinc intake causes zinc deficiency. We hypothesized that dietary restrictions due to food allergy (FA) may be a zinc deficiency risk. Thus, we evaluated the relationship between serum zinc levels and FA in children.

Methods: Children aged 10 months to 6 years were prospectively enrolled; the FA group comprised 73 children with IgE-dependent allergies to hen's egg, cow's milk, or wheat; the control group comprised 49 children without FA. Clinical data and serum zinc, hemoglobin, iron, and 25-hydroxy vitamin D levels were measured and statistically analyzed. The risk factors for zinc deficiency (zinc < 70 μg/dL) were analyzed.

Results: The median age was 2.3 years for both the FA and control groups (p > 0.05). Serum zinc levels were significantly lower in the FA group than in the control group (median [interquartile range]: 70 [64-76] μg/dL vs. 77 [71-85] μg/dL; p < 0.001). Regarding other blood test results, only serum iron levels were significantly lower in the FA group. In the multivariate analysis, hen's egg allergy was the only significant risk factor for zinc deficiency, other FA and atopic dermatitis history were not. In patients with hen's egg allergy, the zinc levels in those with severe dietary restrictions were significantly lower than in the others.

Conclusions: Serum zinc levels were significantly low in the FA group. Notably, hen's egg allergy was a significant risk factor for zinc deficiency. For patients with severe dietary restrictions due to hen's egg allergy, zinc levels should be assessed and appropriate nutritional advice provided.