Form Comparison

Vitamin K1 vs Vitamin K2 MK-7

How vitamin K1 and vitamin K2 MK-7 differ in potency, absorption, tolerance, and cost.

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Quick verdict. K1 clears within hours and goes mainly to the liver for clotting factors; MK-7 has a half-life of about 3 days (Schurgers 2007), giving stable blood levels from 90-180 mcg once daily and more reaching tissues outside the liver, such as bone. Choose MK-7 for a bone-oriented supplement alongside vitamin D, knowing that fracture and arterial calcification evidence is mixed. Anyone on warfarin should take neither without the prescriber's agreement and INR monitoring.

Side by Side

Vitamin K1 (Phylloquinone) Vitamin K2 as MK-7
Absorption Moderate High
How it is absorbed Fat-soluble, absorbed with dietary fat. Taken up mainly by the liver for clotting factor carboxylation; short plasma half-life of a few hours. Long-chain menaquinone, well absorbed with fat and carried in LDL. Half-life of about 3 days (Schurgers 2007) produces stable blood levels with once-daily microgram doses.
Typical dose 90-120 mcg daily (AI for total vitamin K) 90-180 mcg daily
Common uses dietary vitamin K, warfarin reversal (prescription), newborn prophylaxis bone health, paired with vitamin D3
Side effects Antagonizes warfarin; intake must be kept consistent. Even low doses can disturb warfarin anticoagulation; avoid unless the prescriber agrees and INR is monitored.
Cost Low Moderate
Also called phylloquinone, phytonadione menaquinone-7, MenaQ7
Labels in index 19 734

When to Choose Vitamin K1 (Phylloquinone)

Choose vitamin K1 when the goal is meeting vitamin K needs for clotting. Listed here as the reference form for comparison with K2. Leafy greens are the main dietary source.

Vitamin K1 (Phylloquinone)

Choose vitamin K1 when the goal is meeting vitamin K needs for clotting.

What to look for: Vitamin K1 named on the Supplement Facts panel, with the amount per serving stated.

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When to Choose Vitamin K2 as MK-7

Choose vitamin K2 MK-7 when you want once-daily microgram dosing with stable blood levels. Naturally abundant in natto. Outcome evidence for fracture and arterial calcification is mixed.

Vitamin K2 as MK-7

Long half-life, and the form used in the Dutch bone and artery-stiffness trials. Fracture benefit is unproven.

What to look for: 90-180 mcg all-trans MK-7 (MenaQ7 is the trial raw material). Not with warfarin unless the prescriber agrees.

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Products on Titrate

In Titrate's index of NIH label data, 19 labels named as vitamin K2 products list vitamin K1 and 734 list vitamin K2 MK-7.

Open supplement search

Vitamin K2 does not have its own search category yet. Each product above links to its full label in the NIH database.

Related

References

NIH Office of Dietary Supplements. Vitamin K: Fact Sheet for Health Professionals.

Geleijnse JM, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004;134(11):3100-3105.

Cockayne S, et al. Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2006;166(12):1256-1261.

Schurgers LJ, et al. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood. 2007;109(8):3279-3283.

Sato T, et al. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012;11:93.

Theuwissen E, et al. Effect of low-dose supplements of menaquinone-7 (vitamin K2) on the stability of oral anticoagulant treatment: dose-response relationship in healthy volunteers. J Thromb Haemost. 2013;11(6):1085-1092.

Knapen MH, et al. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013;24(9):2499-2507.

Diederichsen ACP, et al. Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial. Circulation. 2022;145(18):1387-1397.