**7. The association of maternal vitamin D status and child vitamin D status**

Several lines of evidence suggest that there is a strong association between maternal 25(OH)D levels during pregnancy and newborn 25(OH)D concentrations at birth or in the early neonatal period [238–242]. Novakovic et al. reported that maternal circulating 25(OH)D levels were the most significant regulator of neonatal circulating vitamin D concentrations, even over the impact of genetic factors [243]. In another study, maternal characteristics explained 12.2%, and maternal 25(OH)D concentrations explained 32.1% of the neonatal vitamin D variance [13]. These results were confirmed in a systematic review reporting the range of correlation coefficients between maternal and newborn 25(OH)D concentrations, by region: European 0.42–0.95, America 0.68–0.97, Western Pacific 0.19–0.85, South-East Asian 0.78–0.81, and Mediterranean 0.03–0.88 [106]. Therefore, since maternal vitamin D status in pregnancy is an important determinant of neonatal 25(OH)D concentrations, attention should be given not only to vitamin D-deficient pregnant women, but also to their newborns, especially if they are exclusively breast-fed [244].
