Scientists at Chang Gung University, Taoyuan, Taiwan, have conducted a study to explore the association between vitamin D serum level and allergen sensitization and their impact on the risk of atopic dermatitis in early childhood.
The study is published in the World Allergy Organization Journal.
Background
Vitamin D is a fat-soluble micronutrient that is crucial in modulating innate and adaptive immune responses. Serum levels of this vitamin are associated with many allergic diseases, including atopic dermatitis.
Existing evidence indicates that the risk of atopic dermatitis is inversely associated with the serum level of vitamin D. However, insufficient evidence is available to understand this association across various age groups during early childhood.
Sensitization to allergens is a strong trigger for atopic dermatitis. While food allergen sensitization typically occurs in infancy, aeroallergen sensitization occurs more commonly in childhood. Serum vitamin D levels exhibit an inverse association with specific allergen sensitization and total serum immunoglobulin E (IgE) levels in early childhood.
In this study, scientists have explored the association between serum vitamin D levels and childhood atopic dermatitis across different age groups. Moreover, they have explored the impact of vitamin D on allergen sensitization and atopic dermatitis during early childhood.
Study design
Children with clinically confirmed atopic dermatitis and age-matched healthy children without atopic dermatitis or other allergic diseases were separately enrolled for the study at 0.5, 2, and 4 years of age.
Among children aged 0.5 years, 59 had atopic dermatitis, and 36 were healthy controls. Among children aged two years, 37 had atopic dermatitis, and 29 were healthy controls. Among children aged four, 32 had atopic dermatitis, and 29 were healthy controls.
Serum samples collected from the participants were analyzed for vitamin D, total IgE levels, and allergen-specific IgE levels.
Important observations
The enrolled children were subdivided into three groups based on their serum vitamin D levels. In the 0.5-year and 4-year age categories, children with a vitamin D level of less than 20 ng/ml showed a significantly higher prevalence of exclusive breastfeeding and maternal atopy than those with a vitamin D level of more than 30 ng/ml.
Children with atopic dermatitis had significantly lower vitamin D levels at 2 and 4 years of age compared to healthy controls. However, a significantly higher vitamin D supplementation was observed in children with atopic dermatitis at 0.5 years of age compared to healthy controls.
The prevalence of food allergen sensitization was significantly higher in children with atopic dermatitis at 0.5 and 4 years of age. The prevalence of mite and IgE sensitization was significantly higher in children with atopic dermatitis at 2 and 4 years of age.
Association between vitamin D level and allergen sensitization
Children with less than 20 ng/ml of vitamin D showed a higher prevalence of food allergen sensitization at 0.5 years of age and mite allergen sensitization at 2 years of age compared to those with more than 30 ng/ml of vitamin D.
In contrast, a significantly higher prevalence of mite and IgE sensitization was observed only in children with less than 20 ng/ml of vitamin D at four years of age.
Atopic dermatitis and allergen sensitization risk factors
Food allergen sensitization and maternal atopy were identified as significant risk factors for the development of atopic dermatitis in children at 0.5 years of age. However, for children at 2 and 4 years of age, the strongest risk factors for atopic dermatitis were serum vitamin D levels and mite allergen sensitization.
Specifically, serum vitamin D level was identified as a significant risk factor for food allergen sensitization at two years of age and for mite allergen sensitization at both two and four years of age.
Study significance
The study finds a strong association between vitamin D deficiency and atopic dermatitis risk and a higher prevalence of allergen sensitization during early childhood.
As hypothesized by the researchers, vitamin D deficiency may alter immune reactions to allergens, which may contribute to atopic dermatitis development in early childhood.
Source：News-medical