Low maternal vitamin D status in pregnancy increases the risk of childhood obesity

Vitamin D may modulate adipogenesis. However, limited studies have investigated the effect of maternal vitamin D during pregnancy on offspring adiposity or cardiometabolic parameters with inconclusive results.

The objective of this study is to examine the association of maternal 25(OH)-vitamin D [25(OH)D] status with offspring obesity and cardiometabolic characteristics in 532 mother-child pairs from the prospective pregnancy cohort Rhea in Crete, Greece.

Maternal 25(OH)D concentrations were measured at the first prenatal visit (mean: 14 weeks, SD: 4). Child outcomes included body mass index standard deviation score, waist circumference, skin-fold thickness, blood pressure and serum lipids at ages 4 and 6 years. Body fat percentage was also measured at 6 years. Body mass index growth trajectories from birth to 6 years were estimated by mixed effects models with fractional polynomials of age. Adjusted associations were obtained via multivariable linear regression analyses.

About two-thirds of participating mothers had 25(OH)D concentrations <50 nmol L^-1 . Offspring of women in the low 25(OH)D tertile (<37.7 nmol L^-1 ) had higher body mass index standard deviation score (β 0.20, 95% CI: 0.03, 0.37), and waist circumference (β 0.87 95% CI: 0.12, 1.63) at preschool age, compared with the offspring of women with higher 25(OH)D measurements (≥37.7 nmol L^-1 ), on covariate-adjusted analyses. The observed relationships persisted at age 6 years. We found no association between maternal 25(OH)D concentrations and offspring blood pressure or serum lipids at both time points.

Exposure to very low 25(OH)D concentrations in utero may increase childhood adiposity indices. Given that vitamin D is a modifiable risk factor, our findings may have important public health implications.