2.3 Role of Early Life Vitamin D in Human Bone Health Term infants with 25(OH)D concentrations above 27.5 nmol/L have higher weight adjusted bone mass than those born with lower concentrations (6). The effects of higher maternal-fetal transfer of vitamin D are sustained long into childhood, as illustrated by a recent report from Southampton, UK (50N latitude): maternal vitamin D status in pregnancy, synonymous with fetal exposure to vitamin D in utero, was positively correlated with bone mass in the children measured as late as 9 years of age (3).