 Undercarboxylated ucOC and carboxylated cOC fractions of osteocalcin will be measured by enzyme-linked immunosorbent assay ELISA. Both the ucOC fraction and the ucOCcOC ratio UCR are sensitive indicators for the vitamin K status of bone. Elevated levels of UCR are indicative of an inferior vitamin K status of bone. The main study parameters are the mean percentages of change in serum undercarboxylated osteocalcin ucOC and UCR from baseline t0 to endpoint t8 weeks in both treatment groups. 