Vitamin K2 (MK-4, MK-7)

Specialist

also menaquinones

What it isVitamin K2 is the bacterially-produced form of vitamin K, found in fermented foods and animal products. MK-4 is short-acting; MK-7 has a much longer half-life.

DoesActivates osteocalcin (which directs calcium into bone) and matrix Gla protein (which keeps calcium out of soft tissues including arteries).

GoodAdequate K2 directs calcium where it belongs and may reduce arterial calcification.

BadInadequate K2 contributes to soft-tissue calcification and bone fragility. Direct measurement is uncommon; undercarboxylated osteocalcin serves as a functional marker.

Standard

Rarely measured directly.

Optimal

No widely-accepted serum optimal

Modifiers

Antibiotics, gut dysbiosis reduce gut bacterial production.

How to optimize

Lifestyle: Resistance training for bone health.
Diet: Natto (MK-7), aged cheeses, butter from grass-fed cows, egg yolks, organ meats.
Supplements: Vitamin K2 MK-7 (180–360µg/day) alongside vitamin D3 — they work together to direct calcium.
Peptides: —
Drugs: —

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