Fig. (1) Serum levels of vitamin K1 in post-menopausal women distributed according to their bone mineral density. (OSP): osteoporotic women group (n = 23). (nOSP): normal bone mineral density group (n =15). The mean serum vitamin K1 level in (OSP) was significantly lower than in (nOSP) (p-value <0.0001 by Mann-Whitney U test).