ESPE Abstracts

Background: It is not an uncommon situation that newborns have normal serum Ca, P, Mg, ALP, and PTH levels despite low vitamin D. Serum vitamin D binding protein (VDBG) may play a role for this situation. However, there is no any study investigated the relationship between serum vitamin D and VDBP in postnatal period.

Objective and hypotheses: The aim of this study is to examine the relationship between serum vitamin D level and VDBP in neonates who have normal serum Ca, P, Mg, ALP, and PTH levels despite low vitamin D and investigate the effect on serum vitamin D level of prophylactic vitamin D dose (400 unite/day).

Method: Mothers and their newborn, whose serum Ca, P, Mg, ALP, and PTH levels were normal, were separated into two groups by their serum vitamin D level (group A, low vitamin D; group B, normal vitamin D). VDBP level was measured in both group. Mothers and their newborn in group A were given 400 unite/day vitamin D. Serum Ca, P, ALP, Mg, PTH, vitamin D, and DVBP levels in group A were re-measured on the postnatal 45–60th days.

Results: Both group A and group B had 30 mother-newborn pairs. There was no difference between group A and B in terms of serum Ca, P, Mg, ALP, and PTH levels of mothers and their newborn, whereas mothers and their newborn in group A had significantly lower vitamin D (P=0.000 and P=0.000, respectively) and higher VDBP (P=0.04 and P=0.004, respectively). On the 45–60th days, mothers’ serum Ca and vitamin D levels significantly increased (P=0.000; P=0.000, respectively), whereas there was no difference in DVBP level. Newborns’ vitamin D level significantly increased (P=0.000), however DVBP level significantly decreased (P=0.004). A negative correlation was found between serum vitamin D level and VDBP in both mothers and newborns (P<0.048, r=−0.239 and P<0.002, r=−0.401, respectively).

Conclusion: Serum Ca, P, Mg, ALP, PTH, and vitamin D levels should be evaluated in both mother and their newborn. If serum vitamin D level is inconsistent with other parameters, this situation may be related to high VDBP level. In that case, prophylactic vitamin D dose should be preferred instead of high dose vitamin D therapy.