Cord Blood 25(OH)-Vitamin D Deficiency and Childhood Asthma, Allergy and Eczema: The COPSAC2000 Birth Cohort Study

Abstract

BackgroundEpidemiological studies have suggested an association between maternal vitamin D dietary intake during pregnancy and risk of asthma and allergy in the offspring. However, prospective clinical studies on vitamin D measured in cord blood and development of clinical end-points are sparse.ObjectiveTo investigate the interdependence of cord blood 25-hydroxyvitamin D (25(OH)-Vitamin D) level and investigator-diagnosed asthma- and allergy-related conditions during preschool-age.MethodsCord blood 25(OH)-Vitamin D level was measured in 257 children from the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2000) at-risk mother-child cohort. Troublesome lung symptoms (TROLS), asthma, respiratory infections, allergic rhinitis, and eczema, at age 0–7 yrs were diagnosed exclusively by the COPSAC pediatricians strictly adhering to predefined algorithms. Objective assessments of lung function and sensitization were performed repeatedly from birth.ResultsAfter adjusting for season of birth, deficient cord blood 25(OH)-Vitamin D level (<50 nmol/L) was associated with a 2.7-fold increased risk of recurrent TROLS (HR = 2.65; 95% CI = 1.02–6.86), but showed no association with respiratory infections or asthma. We saw no association between cord blood 25(OH)-Vitamin D level and lung function, sensitization, rhinitis or eczema. The effects were unaffected from adjusting for multiple lifestyle factors.ConclusionCord blood 25(OH)-Vitamin D deficiency associated with increased risk of recurrent TROLS till age 7 years. Randomized controlled trials of vitamin D supplementation during pregnancy are needed to prove causality.

Maternal and cord blood vitamin D status and childhood infection and allergic disease: a systematic review

“…33,47,48 The 9 studies with nonsignificant results used a variety of 25(OH)D thresholds. 29,30,32,[40][41][42][43][44]46 None of the 6 studies looking at the association between 25(OH)D and allergic rhinitis reported significant associations. 29,30,41,43,44,48 One study mentioned collecting data but did not report on the outcome.…”

“…Most cohorts excluded women with prior serious medical issues, problems during pregnancy, congenital defects, or premature delivery, except as follows: 2 studies (same cohort) included women with prior HIV infection, 26,27 4 studies preferentially recruited parents with a history of allergic disease, [28][29][30][31] and 3 studies included all expectant mothers who presented to the study sites, regardless of health status.…”

“…The remaining 6 studies showed no association between maternal or cord blood 25(OH)D and atopic dermatitis. 30,35,41,43,45,50 One study did not report on the outcome. 37 While 7 studies listed clinician-diagnosed food allergies as one of their measured outcomes, 2 did not report data on this outcome, 35,37 and another was unable to assess allergies because of a small sample size.…”

Maternal antibiotic use and child asthma: is the association causal?

“…The authors also conjectured that maternal vitamin D deficiency could explain the association. Vitamin D is involved in development of the fetal immune system and lungs, and low vitamin D has been associated with higher risk of infections in pregnancy [26] and offspring asthma [27]. Vitamin D supplementation has been shown to reduce risk of infections and, nonsignificantly, antibiotic use [28].…”

Vitamin D and Allergy

“…Cord blood vitamin D level and multi-trigger wheezing, wheezing and risk of troublesome lung symptoms development have been reported to be reversely correlated in three different studies [35,36]. However, recent two different birth cohort studies showed that cord blood vitamin D concentrations were unrelated to atopy and wheeze [37].…”