Longitudinal vitamin D deficiency is inversely related to mite sensitization in early childhood.

Abstract: Background: There are few studies addressing the longitudinal analysis of vitamin D deficiency and its impact on the development of atopic diseases in early childhood. Methods: We investigated 155 children who regularly followed up at our clinic for 5 years as subjects enrolled in a birth cohort study. The pattern of vitamin D levels from birth to 5 years of age was clustered using <italic>K</italic>‐means method in R software. Absolute eosinophil count (AEC), and total serum and specific immunoglobulin E antibodies against food (egg white, milk, and wheat) and inhalant allergens (<italic>Dermatophagoides pteronyssinus, Dermatophagoides farina</italic>, and <italic>Cladosporium herbarum</italic>) were measured at 1.5, 3, 4 and 5 years of age. Results: A total of 137 children with serum samples obtained over at least 3 time points during the follow‐up period were recruited. Using <italic>K</italic>‐means clustering, the dynamic changes in vitamin D levels were significantly stratified into 3 clusters (cluster A, ≥30 ng/mL, n = 61; cluster B, 20‐29.9 ng/mL, n = 53; cluster C, <20 ng/mL, n = 23). Despite no statistical association with atopic diseases, a persistent vitamin D deficiency appeared to be associated with eosinophilia at age 3, and total serum and mite‐specific immunoglobulin E (IgE) levels at age 4. Furthermore, an associated higher prevalence of mite sensitization at age 4 was significantly associated with the risk of allergic rhinitis and asthma. Conclusions: Vitamin D deficiency is inversely associated with AEC and mite‐specific IgE levels, which may potentially increase susceptibility to develop allergies including rhinitis and asthma in early childhood. [ABSTRACT FROM AUTHOR]