Recommended Dose for Vitamin K2 (MK-7)
For general adult supplementation, 100–200 µg of menaquinone-7 (MK-7) daily is the evidence-based dose that improves vitamin K-dependent protein carboxylation without affecting coagulation. 1
General Adult Supplementation
Daily intake of 100 µg MK-7 significantly improves osteocalcin γ-carboxylation and reduces undercarboxylated osteocalcin in healthy adults aged 20–69 years. 1
Doses of 50 µg daily are insufficient to improve vitamin K status markers, while both 100 µg and 200 µg doses produce significant dose-dependent improvements in carboxylated osteocalcin/undercarboxylated osteocalcin ratios. 1
MK-7 at 90 µg daily for 30 days does not alter coagulation factor activity (factors II, VII, IX, X) or prothrombin time in healthy individuals, confirming safety at recommended doses. 2
MK-7 has superior bioavailability compared to MK-4: a single 420 µg dose of MK-7 reaches peak serum levels at 6 hours and remains detectable for 48 hours, whereas MK-4 is not detectable in serum even after consecutive daily dosing. 3
The half-life of MK-7 is very long, with peak plasma concentrations occurring approximately 6 hours after a 1 mg dose under fasting conditions. 4
Special Populations: Hemodialysis Patients
For chronic hemodialysis patients, 360 µg of MK-7 three times weekly (thrice weekly) reduces inactive matrix Gla protein (dp-uc-MGP) by 17%, while 720 µg reduces it by 33%, and 1080 µg by 46% over 8 weeks. 5
Higher doses (720–1080 µg thrice weekly) may be needed in hemodialysis patients due to their markedly elevated baseline levels of inactive MGP and accelerated vascular calcification risk. 5
However, multiple large randomized trials in CKD patients showed no benefit: doses ranging from 200 µg daily to 375 µg daily for 6–24 months failed to reduce coronary artery calcification, aortic valve calcification, or pulse wave velocity progression despite reducing dp-uc-MGP levels. 6
The VitaVasK pilot trial using vitamin K1 (not MK-7) at 5 mg three times weekly showed promise in reducing thoracic aorta calcification in hemodialysis patients, though coronary calcification differences did not reach significance due to small sample size. 6
Parenteral Nutrition Context
For adults on parenteral nutrition, provide 250–500 µg (0.25–0.5 mg) of phylloquinone weekly via lipid emulsions for maintenance. 6
Standard multivitamin preparations add approximately 150 µg, which is more effective at maintaining carboxylation status of non-coagulation Gla proteins. 6
Avoid exceeding 150 µg in patients on warfarin, as higher doses may cause vitamin K antagonist resistance. 6
Important Caveats
MK-4 supplementation is ineffective for raising serum vitamin K levels: even consecutive daily dosing of 60 µg MK-4 for 7 days does not increase serum MK-4 concentrations, whereas MK-7 at the same dose significantly raises serum levels. 3
Gastrointestinal side effects (unpleasant smell/taste) are the main limitation of high-dose MK-7 supplementation, particularly at doses ≥360 µg thrice weekly. 5
Dietary menaquinone intake inversely correlates with dp-uc-MGP levels (P = 0.023), whereas phylloquinone (vitamin K1) intake does not (P = 0.92), suggesting MK-7 is more relevant for extrahepatic tissue vitamin K status. 5
Despite biochemical improvements in vitamin K status markers, clinical trials have not demonstrated cardiovascular benefit in CKD populations, raising questions about whether correcting vitamin K deficiency alone is sufficient to prevent vascular calcification in advanced kidney disease. 6