Cord Blood 25-Hydroxyvitamin D Level is Correlated with a Risk for Atopic Dermatitis: Systematic Review and Meta-Analysis

Although Indonesia is located in an equatorial region with adequate year-round sun exposure, the prevalence of 25-hydroxyvitamin D (25[OH]D) deficiency is as high as 90%. Mothers are especially vulnerable to deficiencies due to changes in their gastrointestinal system. Previous studies have reported a correlation between the 25[OH]D status of mothers with atopic dermatitis (AD) and their offspring. However, studies investigating maternal cord blood 25[OH]D levels and the incidence of AD have yielded controversial results due to its variability. As such, this systematic review and meta-analysis aimed to evaluate the correlation between maternal cord blood 25[OH]D levels and the risk for AD. In accordance with Preferred Reporting System for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Cochrane Library and ScienceDirect databases were searched for relevant observational studies and a meta-analysis was performed to obtain odds ratios (OR) and corresponding 95% confidence intervals (CI). Nine studies were included in the qualitative synthesis, five of which were included in the quantitative synthesis. Meta-analysis revealed that cord blood 25[OH]D levels < 50 nmol/L were associated with a 60% higher risk for the development of AD (OR = 1.60; 95% CI: 1.15, 2.22; I-2 = 0%; P < 0.05). However, qualitative synthesis revealed a variety of cord blood 25[OH]D measurements and different methods of diagnosing AD in each study. Based on the current analysis, maternal cord blood 25[OH]D levels were significantly correlated with the risk for AD. Therefore, studies investigating 25[OH]D supplementation in pregnant women and its efficacy in decreasing the risk for AD are needed, especially in tropical and equatorial countries. This study also serves as a proof of concept that cord blood 25[OH]D levels can be used as a more affordable predictive parameter for AD.