Vitamin K2 MK-4

How strong is the research?

1 paper read, 1 supporting.

Tested as: Vitamin K2 (MK-7)

Who was studied: Said to be Japanese adults with osteoarthritis at a high dose, but the cited paper cannot be found.

The research we could find tested Vitamin K2 (MK-7). That is a different preparation, and a result for one form is not a result for another.

How much to take

daily

15–45 mg

MK-4 requires higher doses than MK-7 due to shorter half-life. Divide into 3 doses.

Before you take it

• NIH ODS (FNB/IOM): No Tolerable Upper Intake Level (UL) has been established for vitamin K in any form, including MK-4 (menatetrenone); no adverse effects from high vitamin K intake have been demonstrated in healthy adults.
• Vitamin K2 antagonizes vitamin K antagonist anticoagulants (warfarin, acenocoumarol, phenprocoumon); patients stabilized on these drugs must not begin, stop, or substantially change K2 supplementation without medical supervision, as INR destabilization can cause dangerous thrombotic or hemorrhagic events.
• Bile acid sequestrants (cholestyramine, colestipol) and fat-absorption inhibitors (orlistat) reduce intestinal absorption of fat-soluble vitamin K and may lower K2 status in long-term users.
• Certain antibiotics, particularly cephalosporins, can inhibit gut bacterial vitamin K synthesis; broad-spectrum antibiotic courses may transiently lower vitamin K status.
• Clinical trial evidence for bone effects uses 45 mg/day of pharmaceutical menatetrenone (Glakay, approved in Japan as a drug); typical consumer supplement doses of MK-4 range from 1–15 mg/day, and efficacy data from 45 mg/day trials does not establish equivalent efficacy at lower supplement doses.

When to take it

Best taken: with food

What we make of it

The identifier does not lead to a joint pain study.