Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

Sato T, Schurgers LJ, Uenishi K · Nutrition Journal

MK-4 was undetectable in serum at every time point at nutritional doses, while MK-7 was well absorbed (serum peak ~6 h) and accumulated with daily dosing — the key pharmacokinetic argument for MK-7 over MK-4 at supplement-label doses.

Population

Ten healthy Japanese women aged 20-21, randomised to two groups of five in each of two studies: a single 420 microgram dose, or 60 micrograms a day for 7 days

Intervention

Menaquinone-4 (MK-4) vs menaquinone-7 (MK-7), single-dose and 7-day dosing

Comparator

MK-4 vs MK-7 head-to-head

Limitations

Five per group; the first author is employed by J-Oil Mills, which prepared the capsules (competing-interests statement; no funding source is stated); measures serum levels, not joint outcomes; high-dose MK-4 (45 mg/day) regimens not tested.