Plasma levels of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 in maternal,cord and neonatal blood.

Publisher Website
Google Scholar
Abstract
A high-performance liquid chromatographic method for simultaneous assay of 25-hydroxyvitamin D2 (25-OH-D2) and 25-hydroxyvitamin D3 (25-OH-D3) proposed in a previous paper was applied to determine the plasma levels of the metabolites in perinatal and postnatal periods. The plasma samples of maternal, cord and neonatal blood were collected in summer and winter seasons. 25-OH-D3 was detected in all the samples. The plasma levels of the metabolite in mothers, cords and newborn infants (within 24 h of birth) in summer were 33.9 .+-. 12.5, 18.9 .+-. 8.4 and 16.6 .+-. 6.4 (mean .+-. SD) ng/ml, while those in winter were 15.8 .+-. 6.6, 8.8 .+-. 3.4 and 7.7 .+-. 3.2 ng/ml. The data in summer was significantly higher than the respective data in winter and there were high significant correlations between mothers and cords and between mothers and newborns. In both seasons, the plasma levels of mothers were about 2 times higher than the respective data of cords and newborns which were nearly identical with one another. A similar tendency was always observed in the individual data of mothers-cords-newborns pair samples. Many plasma samples from mothers, cords and newborns were examined, but 25-OH-D2 was detected in only few samples (6/41 for mothers, 3/36 for cords and 2/34 for newborns). The metabolite began to appear in all the samples during nursing with vitamin D2-fortified dry milk to show 4.6 .+-. 1.3 and 4.8 .+-. 1.2 ng/ml in the summer and winter samples of neonates 5-6 days old, respectively. When the variation of plasma 25-OH-D2 and 25-OH-D3 levels was examined in postnatal periods up to 1 mo., the levels of exogenous 25-OH-D2 were increased while those of endogenous 25-OH-D3 were decreased. The amount of vitamin D2 intake from fortified dry milk was highly significantly correlated with the plasma levels of 25-OH-D2, which indicates that daily intake of exogenous vitamin D2 is very important in nutrition during postnatal periods of bottle-fed infants.