S-25-hydroxyvitamin D and C3-epimers in pregnancy and infancy: An Odense Child Cohort study.

Background: Analysis of serum 25-hydroxyvitamin D (s-25(OH)D) may be complicated by the less active or in-active vitamin D metabolite C3-epi-25(OH)D (C3-epimer). We aimed to explore the relationship between s-C3-epimer and s-25(OH)D and other determinants and describe the longitudinal course of the C3-epimer fraction in paired mother-child samples.

Method: S-25(OH)D and s-C3-epimer were estimated by liquid chromatography mass spectrometry in 290 mother-infant pairs from the population-based Odense Child Cohort.