Accumulation and efficacy of K vitamins during long-term daily administration. Participants received in a crossover design either K₁ (○) or MK-7 (•) or placebo; in the latter case only K₁ (▴) could be detected. Points are means of 18 values; error bars represent SD. (A) Circulating levels of vitamin K; baseline levels for K₁ were subtracted; no MK-7 could be detected at baseline. (B) Ratio between circulating carboxylated and undercarboxylated osteocalcin (cOC/ucOC); at baseline the ratio was 1.74 for MK-7, 1.8 for K₁, and 1.7 for the placebo group.