Vitamin D deficiency in children and adolescents with food allergy

Our objective was to describe the serum vitamin D concentrations of children and adolescents with food allergy (FA) and to verify the association between the number of food allergens involved, length of sun exposure, and nutritional status. Through a cross-sectional study, 79 patients with FA, from ages 2 to 15 years, were assessed and followed up in a reference out-patient clinic, in Sao Paulo, Brazil. Clinical and biochemical data were collected for analysis of 25(OH)D, calcium, phosphorus, phosphatase, parathyroid hormone (PTH), and high-sensitivity C-reactive protein (hs-CRP). The cut-off point used for vitamin D deficiency was 25(OH)D ≤ 20 ng/mL. Vitamin D deficiency was detected in 45.6% of patients with a median age of 6.9 years (Interquartile range [IQR] 4.7; 10.2). The median serum 25(OH)D concentration was 21.1 ng/ mL (IQR 17.8; 26.0). Multivariate linear regression was performed considering serum vitamin D level as a dependent variable. Allergy to multiple foods (inverse) and length of sun exposure (direct), but not nutritional status, were independently associated with serum 25(OH)D levels (P = 0.034 and P = 0.014, respectively). Patients with cow’s milk allergy also showed lower vitamin D concentrations in comparison with other FA (19.1 ng/mL [IQR 16.6; 24.4] vs 22.2 ng/mL [IQR 18.1; 27.1] [P = 0.056]). Vitamin D deficiency affected about half of individuals with FA. Multiple food allergy was associated with lower vitamin D concentrations, reinforcing the importance of monitoring vitamin D status in patients with FA.