Error bars represent SEMs Bone turnover markers BALP, a surrogate of bone formation, increased dramatically
from baseline MM-102 (repeated measures MANOVA; p < 0.001) (Fig. 3a), while TRACP concentration remained at the same level during the 14 months (Fig. 3b). At the 14-month visit, TRACP, BALP, or their ratio did not differ between the groups. There was no correlation between BALP and TRACP, but ΔTRACP correlated positively with Δ25-OHD (=25-OHD14 month − 25-OHDpregnancy mean) (r = 0.345, p = 0.012). Correspondingly, ΔBALP correlated inversely with Δ25-OHD (r = −0.213, p = 0.034). The correlations were similar in both groups. Fig. 3 Concentrations of BALP and TRACP in study groups from baseline to 14 months. Low D and High D are represented by circles and squares, respectively.
Error bars represent SEM. BALP increased from baseline (repeated-measures MANOVA; p < 0.001) (a) while TRACP concentration remained at the same level during the 14 months (b). There were no differences between the study groups Discussion This prospective study made three key findings. Firstly, distal tibia CSA remained larger at 14 months in infants with higher maternal vitamin D status during pregnancy than in infants with lower maternal vitamin D status. Secondly, the increment in tibial BMC from birth to 14 months was higher in those with inferior maternal vitamin D status during pregnancy. This resulted in similar BMC and BMD at 14 months in both study groups. Finally, 20% of the children had S-25-OHD below 50 nmol/l at 14 months of age, although their median total intake of vitamin Adavosertib clinical trial D was 12.2 (3.0) μg, which meets the Nordic recommendation for this age group . Other interesting findings related
to bone growth in this prospective cohort were that boys had higher BMC, and BMC increased more during the 14 months and resulted in higher volumetric BMD in distal tibia than in girls. Children in high vitamin D group learnt to walk with support later than children in low vitamin D group, although other ALOX15 developmental milestones were similar. We consider this as a random finding because it is unlikely that higher maternal vitamin D status would contribute to this and several studies have witnessed that vitamin D IWR-1 chemical structure deficiency is related to delayed age of walking [24, 25]. In this study, walking age without support was inversely related to tibia BMC and CSA, suggesting that earlier walking enhances bone development. Similarly jumping is shown increase the outer diameter of the tibia in a randomized controlled trial of 3- to 5-year-old children . Walking is one of the first weight-bearing exercises modifying the strength of the tibia, but it is unsure if the association between walking age and bone health will preserve in the future. Surprisingly, longer exclusive breastfeeding was linked to lower bone development, which might be a sum of prolonged growth rate  and possible lower intakes of nutrients.