Je SH, et al. • Vitamin K Supplement and BMD, UcOC Changes to induce responses in related biochemical markers and total BMD. Moreover, we did not measure and compare the dietary vitamin K intake. Also, bone quality was not measured, which might be only a minor limitation. A previous study (6) suggest- ed that UcOC concentration is inversely associated with age, with higher UcOC concentrations in younger women. This sug- gests that the effect of the vitamin K on osteocalcin may also be age-related. Given the advanced age of our study subjects (mean age 68 yr) and relatively short treatment period, the study may have not been able to discern an increase all part of BMD. How- ever, it is noteworthy that changes in UcOC concentration among older women have been reported, with UcOC concentration in women in their 50 sec being higher than that in women in their 60 sec and 70 sec (6). Therefore, vitamin K may be more effec- tive in preventing bone loss or improving BMD in women aged 50-59 yr, especially in perimenopausal women or women with few years of menopause. A study testing the influence of vitamin K supplementation to perimenopausal women or women with few years of menopause for more than 6 months is needed. In addition, inconsistent findings from different countries suggest that a comparison of Korean data with data from other coun- tries is warranted. A study design involving a longer duration of vitamin K supplementation and with postmenopausal women having a short duration of menopause may prove valuable. Fi- nally, physical activity was not measured. In conclusion, in this randomized study, supplementation with vitamin K, D and calcium for 6 months improves L3 BMD and reduces UcOC concentration in Korean postmenopausal women over sixty. REFERENCES 1. Rowe SM, Song EK, Kim JS, Lee JY, Park YB, Bae BH, Hur CI. 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