Cord serum 25-hydroxyvitamin D correlates with early childhood viral-induced wheezing

Background: There are investigations concluding that reduced vitamin D status in pregnancy, may be a risk factor for the development of allergic outcomes in offspring. However, studies on the relationship between cord levels of 25-hydroxyvitamin D (25[OH]D) and risk of early childhood wheezing and early-onset atopic dermatitis/food allergy are very limited.

Objective: To assess the associations between cord blood concentration of 25[OH]D and occurrence of the incidence of wheezing, atopic dermatitis, food allergy, during the first two years of life.

Methods: We evaluated 240 children by the age of 2 years from the Polish Mother and Child Cohort Study. Women were interviewed during pregnancy to collect demographic and socioeconomic data, the medical and reproductive history. At delivery, umbilical cord blood plasma was sampled. The child's health status were examined at approximately 2 years. In the analyses multivariable model was used.

Results: Data from 190 participants were included into the analysis. The median value and quartile range of 25[OH]D in cord blood [ng/ml] were as follows: 6.33, 4.16-8.53. 25[OH]D in cord blood below lower quartile increases the risk of multi-triggered wheezing (MTW) in children during first 2 years of life (OR: 2.81; 95% CI: 1.13-7.00). Higher cord serum level of 25[OH]D reduces the risk of viral induced wheezing (VIW). The cord serum level of 25[OH]D below median value (OR: 6.06; 95% CI: 1.3-28.3) or below lower quartile (OR: 5.43; 95% CI: 1.66-17.7) increases the risk of VIW. All above effects of vitamin D level in cord blood were corrected for the effects other independent risk factors of wheezing and VIW in this cohort.

Conclusions: Cord serum 25[OH]D levels were inversely associated with the risk of multi-triggered wheezing, and especially viral-induced wheezing by the age of 2 years, but no association was found with food allergy, atopic dermatitis and frequencies of infections.