Pregnancy or cord 25-hydroxyvitamin D is not associated with measures of body fat or adiposity in children from three months to three years of age. An Odense Child Cohort study.

Background & Aims: The susceptibility to overweight in adults born during winter season may suggest foetal programming of prenatal vitamin D levels on adiposity. We investigated whether cord or pregnancy serum 25-hydroxyvitamin D (s-25OHD) was associated with infant and child body fat measures in a Danish population-based prospective cohort.

Methods: In the Odense Child Cohort, 1905 singletons had cord s-25OHD and data on waist circumference (WC), weight, body mass index (BMI), and sum of skin folds (SSF) at median 3.7 months, 18.9 months and three years' age. Early and late pregnancy samples of s-25OHD (mean gestational age 12 and 29 weeks) were chosen as secondary exposures. Multiple linear and logistic regression as well as linear mixed models was applied testing the relation between cord and pregnancy s-25OHD and body fat outcomes and their Z-scores by use of updated national reference populations. Models were adjusted for maternal educational level, maternal ethnicity, pre-gestational BMI and season of birth, a priori stratified by sex.

Results: The median [IQR] cord s-25OHD was 45.5 [31.1; 60.9] nmol/L. Cord s-25OHD <50 nmol/L was found in 57.5%; values < 25 nmol/L in 16.3%. The mean Z-scores of body fat measures at all ages were in the range of -0.32 to +0.42. No consistent associations were found between s-25OHD in cord, early pregnancy or late pregnancy and WC, weight, BMI, SSF, or their Z-scores at ages 3.7 months, 18.9 months, or 3 years. Neither did a computed composite outcome (WC, SSF, BMI, or weight >90th vs. ≤90 percentile) associate with cord or pregnancy s-25OHD.

Conclusion: Cord or pregnancy s-25OHD was not associated with measures of body fat or adiposity in children up to three years of age. Our data suggested no programming effect of maternal s-25OHD on offspring obesity in a relatively lean and healthy population of mothers.