Role of Cadmium and Folate Levels in Risks of Allergic and Respiratory Diseases of Early Childhood: The Mothers and Children's Environmental Health Study

Rationale: Maternal diet affects offspring DNA methylation. However, the results for the effect of cadmium and folate status during pregnancy or childhood on development of allergic or respiratory disease are still unknown. 

Methods: In total, 917 mother–child pairs from a prospective birth cohort in South Korea were studied. Data regarding the children’s allergic and respiratory outcomes were obtained from questionnaires by the mothers at postnatal months 6, 12, and 24. Serum cadmium and folate levels were measured in the mothers at mid- and late pregnancy, and in their children at 24 months of age. Atopic biomarkers were measured in the cord blood (CB) and at 24 months after birth. At 24 months data of 462 children were available.

Results: We compared the individuals of high folate with those of low folate. Individuals of high folate during  had lower levels of cadmium (1.51 µg/L vs 1.44 µg/L, p<0.05 at mid pregnancy: 1.59 µg/L vs 1.56 µg/L, p<0.01 at late pregnancy). Higher folate (≥9.5ng/ml) with lower cadmium (<1.5 µg/L) levels during mid pregnancy were associated with increased risk of AD at 24months of age (adjusted odds ratio [aOR] 0.36, 95% CI (0.14 to 0.95), p=0.04. However there was no relationship between cadmium or folate levels at 24 months of age and risk of allergic or respiratory diseases.

Conclusions: Higher folate with lower cadmium levels during pregnancy may contribute to increase the risk of AD in early childhood.