sentences:  Bioavailability studies have shown that small oral doses are not detected in the blood – for example 420 mcg of menatetrenone or less tested over minutes and hours are not detectable, and larger doses in the order of milligrams are required, unlike vitamin K2 MK-7 which is detectable in the blood in mcg doses.Furthermore, "administered daily doses of 15, 45, 90, and 135 mg revealed that 45 mg was the minimum effective dose for improving bone mass parameters evaluated by microdensitometry and/or single photon absorptiometry in postmenopausal women with osteoporosis".The study referenced is also available in Japanese.