Relations of plasma 25-hydroxyvitamin D levels in mothers, cord blood and newborn infants, and postnatal changes in plasma 25-hydroxyvitamin D levels

Abstract

The plasma levels of 25-hydroxyvitamin D (25-OH-D) were determined in 27 healthy mothers and their infants as well as in the cord blood at the time of delivery, and in another 95 children of different ages. The plasma 25-OH-D levels in the infants, cord blood and mothers at the time of delivery were 11.4±8.6 ng/ml (mean±SD, n=27), 12.8±8.2 ng/ml (mean±SD, n=25) and 16, 3±8.1 ng/ml (mean±SD, n=27), respectively. These values are significantly lower (p<0.01) than the value of 21.6±10.1 ng/ml (mean±SD, n=17) in normal children (1-15 years of age). Significant correlations were found between the plasma 25-OH-D levels of the infants and the mothers, and between those of the mothers and cord bloods, with correlation coefficients of r=0.62 (p<0.01, n=27) and r=0.78 (p<0.01, n=25), respectively. The plasma 25-OH-D concentration was normally maintained at a low level for 1-2 months after birth and then rose. No significant correlation was found between the plasma 25-OH-D and plasma Ca levels. The above findings suggest that 25-OH-D is transferred from the mother to the infant through the placenta, but that the blood 25-OH-D level is low for a few months after birth, possibly owing to a low rate of 25-hydroxylation of vitamin D during this period. © 1979, Center for Academic Publications Japan. All rights reserved.