Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Well below target. Risk of deficiency symptoms tied to coagulation · bone.
Below the recommended daily target. Long-term adequacy not assured.
Daily target met. Standard nutritional support for coagulation · bone.
Common for specific health goals. Check the evidence for your situation before sustaining this level.
Past the point where extra intake typically helps. Evidence for further benefit is thin.
You're at 0% of your vitamin k target. The biggest single-serving sources to top it off:
Essential cofactor for gamma-carboxylation of glutamate residues on proteins involved in coagulation (factors II, VII, IX, X) and calcium handling (osteocalcin, matrix Gla protein). Two main families: K1 (phylloquinone) from green plants, K2 (menaquinones MK-4 through MK-13) from fermented foods and animal tissues.
GGCX enzyme uses vitamin K hydroquinone as cofactor to carboxylate glutamate residues, creating Gla residues that chelate calcium. Carboxylation oxidises K to its epoxide; VKORC1 recycles it. Warfarin inhibits VKORC1, depleting active K and inactivating clotting factors — the basis for its anticoagulant action.
Overt deficiency causing bleeding is rare in adults due to gut bacterial K2 production and recycling. Subclinical insufficiency for extra-hepatic Gla proteins (osteocalcin, MGP) is more common.
No established UL; toxicity from natural K1/K2 has not been reported. Synthetic menadione (K3) is hepatotoxic and not used in human supplements.
K2 as MK-7 has a much longer half-life (~3 days) than MK-4 (~1 hour) — once-daily MK-7 dosing is practical; MK-4 needs split doses to maintain levels. K1 is well-covered if you eat cooked greens regularly. Typical MK-7 dose: 90–180 mcg/day with a fat-containing meal.
K1 from leafy greens is poorly absorbed (~10%); cooking with fat triples uptake. K2 from natto is the most bioavailable food form. All forms require bile and dietary fat for absorption.
The Rotterdam Study found dietary K2 (not K1) inversely associated with coronary calcification, CHD mortality, and all-cause mortality. Mechanism likely via MGP activation preventing vascular calcium deposition. K1 still matters for clotting but the longevity signal is concentrated on K2.
Blood clotting and bone matrix protein activation.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.
★ = load-bearing / primary cofactor. Track these in My Journey.
Whole foods that contribute meaningfully (≥10% DV per 100 g serving). Click any food to see its full nutrient profile and what else it brings to the table.
See all foods high in Vitamin K, ranked →