Vitamin D status and tooth enamel hypomineralization are not associated in 4-y-old children: An Odense Child Cohort study.

Early fetal stages of tooth development are vitamin D-dependent, suggesting an impact of vitamin D status in pregnancy on tooth mineralization in human populations. We examined the association between pregnancy and cord serum 25-hydroxyvitamin D (s-25(OH)D) and hypomineralization of the second primary molars (HSPM) in the 4-year-old children in the prospective, population-based Odense Child Cohort, Denmark. S-25(OH)D was measured in early pregnancy (<20 weeks, n = 753); late pregnancy (≥20 weeks, n = 841); and in umbilical cord blood (n = 1,241) using liquid chromatography-tandem mass spectrometry. HSPM was scored using modified European Academy of Paediatric Dentistry judgment criteria. The median [Q1;Q3] s-25(OH)D was 65.0 [49.4;78.0], 79.2 [60.4;95.8], and 45.1 [31.2;60.5] nmol/L in early pregnancy, late pregnancy, and cord blood, respectively. The prevalence of HSPM was 54.7%; creamy/white demarcated opacities 79.5%; yellowish/brownish demarcated opacities 14.9%; post-eruptive breakdown 5.2%; atypical restoration 0.4%. No univariate or adjusted associations with HSPM were detected for pregnancy or cord s-25(OH)D as a continuous variable or categorized into quartiles or routine clinical cut-offs, or when classifying HSPM by severity. In exploratory multiple regression analysis, HSPM was inversely associated with the length of gestation, adjusted odds ratio (aOR) 0.82 (95% C.I 0.74-0.92, p < 0.001), and directly associated with maternal education, aOR 1.57 (95% C.I 1.18-2.08, p = 0.002). In a population with relatively high s-25(OH)D concentrations and generally healthy mothers and children, pregnancy and cord blood vitamin D status was not associated with HSPM. The associations between HSPM and shorter gestational length and higher maternal education warrant further study.