Vitamin D and iron status in children with food allergy.

Background: Children with food allergy are at specific risk for nutritional deficiencies.

Objective: To retrospectively determine prevalence of vitamin D and iron deficiencies in children with or without food allergy (FA).

Methods: We compared the markers of vitamin D and iron status of 0 to 17-year-olds with cow's milk allergy (CMA) (n = 77), those with other FAs (n = 70), and those with atopy without FA (n = 87) at an academic pediatric allergy practice. Multiple linear regression analyses were performed to determine the impact of CMA and other FAs on vitamin D levels and iron markers.

Results: Vitamin D deficiency was detected in one-fourth and insufficiency in one-third of children with CMA and other FAs and in those with atopic diseases but no FA, respectively. Vitamin D levels were associated with vitamin D supplementation and consumption of breast milk, cow's milk, infant formula, or plant-based milk beverage, but not with CMA or other FAs. Older children with FA who did not consume any cow's milk or alternative milk beverage were at highest risk for vitamin D insufficiency. Children with CMA have a higher rate of iron deficiency anemia (8%) than children with other FAs (1%) or those with no FA (5%, P < .001); however, suboptimal levels of transferrin saturation and iron were detected in up to one-third of children with CMA or other FAs.

Conclusion: Vitamin D deficiency and insufficiency is common in children with atopy overall, but children with CMA are at higher risk for iron deficiency anemia. Intensive nutritional counseling and nutrient intake monitoring, specifically for vitamin D and iron in those avoiding cow's milk, are necessary to optimize nutritional status.