Summary
Osteocalcin (bone Gla-protein) is a vitamin K-dependent protein synthesized by osteoblasts.
Its hydroxylapatite binding capacity (HBC) is generally used to estimate the Gla-content
of circulating osteocalcin. Here we have used the HBC of serum osteocalcin as a marker
for the vitamin K-status in pregnant women and their offspring. For all cases investigated
the HBC values in the cord samples were substantially lower than in the corresponding
maternal ones. Babies from mothers who had been treated with vitamin K during the
last 6 weeks prior to delivery, had significantly higher HBC values than those from
a placebo group. The results presented in this paper are indicative for a generally
occurring vitamin K deficiency in newborns. At delivery the HBC in untreated women
was low as well. In both the placebo- and the vitamin K-group a good correlation was
found between the HBC values in paired samples from mother and child. Whether the
maternal HBC value may be used as a prenatal marker for estimating the fetal vitamin
K-status remains to be seen.
