PURPOSE OF THE STUDY.
To investigate the relationship of maternal and cord blood vitamin D levels on atopic outcomes in early childhood.
A total of 378 mother-infant pairs from Leipzig, Germany, a subgroup of the LINA (Lifestyle and environmental factors and their Influence on Newborns Allergy risk) cohort study, were included. Mothers with immune or infectious disease concerns during the pregnancy were excluded.
Blood samples were collected from expectant mothers at the 34th week of gestation and from infant cord blood at delivery for measurement of vitamin D (25[OH]D3). Regulatory T cells were also quantified from cord blood samples. Total IgE and allergen-specific IgE measurements were determined at birth (cord blood) and at 1 and 2 years of age in participating children. During pregnancy and at the children’s first and second birthdays, parents completed questionnaires regarding family history of atopy, housing and environmental conditions, and atopic outcomes of their children (doctor-diagnosed atopic dermatitis and/or food allergy or parental report of symptoms consistent with atopic dermatitis).
A high correlation was observed between maternal and cord blood 25(OH)D3 levels (R = 0.812, P ≤ .001). Most pregnant women included in the study were either 25(OH)D3 deficient (<20 ng/mL; 44%) or insufficient (20–29.9 ng/mL; 25.7%), and few received vitamin D supplementation during pregnancy. Maternal 25(OH)D3 levels were positively associated with children’s risk of diagnosis of food allergy (adjusted odds ratio [aOR]: 3.66; 95% confidence interval [CI]: 1.36–9.87) in the second year of life or within the 2-year lifetime period (aOR: 1.91; 95% CI: 1.09–3.37), and with sensitization to food allergens (aOR: 1.59; 95% CI: 1.04–2.45) in the second year of life. Cord blood 25(OH)D3 levels were associated with diagnosis of food allergy in the second year of life (aOR: 4.65; 95% CI: 1.50–14.48) and negatively correlated with regulatory T-cell numbers (R = −0.168, P = .031).
Higher vitamin D levels in pregnancy and at birth were associated with a higher risk of food allergy and lower numbers of regulatory T cells.
The role of vitamin D in the development of atopic disease remains unclear. Whereas some previous studies have suggested that maternal vitamin D deficiency may increase the risk of developing allergy, and may even be a key reason behind the rapidly rising prevalence of food allergy, this study suggests the complete opposite. Although vitamin D supplementation may be advised for many reasons, the prevention of allergy is not yet one of them.
- Copyright © 2013 by the American Academy of Pediatrics