Cord Blood Epimer Levels and Autism Traits at Age 10
Cord blood 3-epi-25(OH)D3 concentrations show a rank-based inverse association with parent-reported autism-related traits in children at age 10, according to an exploratory analysis published by MDPI. The investigation evaluated 87 mother-child pairs from the KLOTHO cohort, applying liquid chromatography-tandem mass spectrometry to isolate the vitamin D metabolite from conventional 25(OH)D3 measurements.
Metabolite Separation and Fetal-Placental Phenotypes
Chromatographic separation remains critical because the C3 epimer can otherwise inflate measured 25(OH)D3 concentrations during pregnancy and infancy. However, researchers emphasize that the epimer is not established as a neurodevelopmentally active ligand at the concentrations studied. Placental transport, maternal metabolic factors, and enzymatic activity shape the cord epimer pool, meaning the observed association may identify a fetal-placental metabolic phenotype rather than direct epimer neuroactivity.
Conflicting Domain Scores and Statistical Adjustments
Trait-domain results in the cohort diverged across behavioral categories. A higher cord epimer concentration correlated with lower cognitive-domain scores, yielding a Spearman correlation coefficient of negative 0.412. Conversely, the same epimer levels correlated with higher social and emotional scores at a coefficient of positive 0.302. Because higher scores on the Australian Scale for Asperger’s Syndrome denote more autism-related characteristics, these opposite directions of association preclude labeling higher epimer concentrations globally protective.
Furthermore, initial crude linear estimates weakened significantly after covariate adjustment, and a tertile analysis yielded non-significant results. The study did not measure placental or neural intermediates, and modest sample sizes for sex-stratified regressions left direct between-sex contrasts statistically non-significant.