Whole-body bone mass in the neonatal period according to gestational weight gain categories and maternal 25(OH)D status. Data are reported as mean ± SD and were analyzed using a mixed linear model accounting for the fixed effects of infant’s sex, age, and LAZ score and mother’s 25(OH)D categories, pre-pregnancy BMI categories, gestational weight gain categories, education, self-reported population group as well as family income (p < 0.05, post hoc adjustment). Abbreviations: 25(OH)D: 25-hydroxyvitamin D, WB BMC: whole-body bone mineral content, WB BMC/kg: whole-body bone mineral content per kilogram body weight.