It is produced via conversion of vitamin K1 in the body, specifically in the testes, pancreas and arterial walls.
[7] Menatetrenone is approved in Japan for second-line treatment of postmenopausal osteoporosis.
Evidence is restricted to small-scale RCTs; the minimum effective dose (for bone mass parameters) is 45 mg, much higher than the Daily Value for vitamin K (80 μg).
[8] 420 μg of oral MK-4, in a single-dose or spread out over 7 days, does not cause detectable changes in serum MK-4 level in healthy women, whereas MK-7 produces the expected increases in MK-7 levels.
[1] The minimum effective oral dose to change serum osteocalcin levels is 1500 μg/d, where as oral MK-7 is effective on this parameter at 45 μg/d, a level more in line with nutritional intake.