nutrient

Vitamin K

A family of fat-soluble vitamins used in blood-clotting protein activation and bone-related protein function.

Phylloquinone (K1) is common in leafy plants; menaquinones (K2) include several forms. The forms share vitamin K activity but have different food sources and handling.

What it does

Vitamin K is required for gamma-carboxylation, a modification that activates several proteins involved in coagulation and bone metabolism.

Where it comes from

The AI is based on phylloquinone, not a summed conversion of every menaquinone. Leafy greens and some fermented foods provide different forms.

Food sources

Per 100 g
Food amounts and reference percentages, both per 100 g
FoodPer 100 gDaily reference
Spinach, raw (SR Legacy 2018)483 µg690%
Hummus, commercial17.2 µg24.57%
Carrots, frozen and unprepared15 µg21.43%
Grape tomatoes, raw4.2 µg6%
Ground flaxseed3.68 µg5.26%
Show 10 more foods
Food amounts and reference percentages, both per 100 g
FoodPer 100 gDaily reference
Atlantic sardines, canned in oil (SR Legacy 2018)2.6 µg3.71%
English walnuts, raw1.7 µg2.43%
Lentils, cooked and salted (SR Legacy 2018)1.7 µg2.43%
Russet potato, raw1.5 µg2.14%
Atlantic salmon, farmed, raw (SR Legacy 2018)0.5 µg0.71%
Oat milk, unsweetened and refrigerated0.4 µg0.57%
Plain whole-milk yogurt0.2 µg0.29%
Orange sweet potato, peeled and raw0.2 µg0.29%
Banana, ripe, raw0.1 µg0.14%
Atlantic salmon, farmed, cooked (SR Legacy 2018)0.1 µg0.14%

Compared with EFSA’s adult reference of 70 µg/day.

About these amounts

These values describe the named food and preparation. A 100 g comparison is not a suggested serving. Small amounts are rounded for display; an unreported amount is not zero.

Healthy European adults; phylloquinone. Adequate intake: 70 µg/day. These are population references, not individual targets.

Portions recorded by the source

  • Hummus, commercial: 2 tablespoon (33.9 g) — 5.83 µg, 8.33% of the daily reference.

The source records and EFSA guidance are linked in References below.

Forms

  • Vitamin K1 (phylloquinone) is a form of Vitamin K.

    Vitamin K1 (phylloquinone) is a named chemical form within its parent vitamin family.

  • Vitamin K2 (menaquinones) is a form of Vitamin K.

    Vitamin K2 (menaquinones) is a named chemical form within its parent vitamin family.

  • Menaquinone-4 (MK-4) is a form of Vitamin K.

    Menaquinone-4 (MK-4) is a named chemical form within its parent vitamin family.

  • Menaquinone-7 (MK-7) is a form of Vitamin K.

    Menaquinone-7 (MK-7) is a named chemical form within its parent vitamin family.

Roles and processes

  • Vitamin K supports protein activation in Bone

    Vitamin K activates proteins involved in bone metabolism through gamma-carboxylation.

Worth knowing

  • Form matters with anticoagulants. Vitamin K intake can be clinically relevant with vitamin-K-antagonist medicines. Changes should be discussed with the prescribing team before altering food or supplement intake.

  • Food tables do not show every K form. Food composition tables mainly report phylloquinone because measurements for menaquinones are limited. A missing K2 value can reflect the method used rather than proof that no menaquinone is present.

A closer look

Evidence remains form-specific

Research on menaquinones does not change the fact that EFSA’s AI is expressed for phylloquinone.

K2 is not one measured substance

Menaquinones include MK-4 through MK-13 and have different sources. Limited data on their food content and relative bioavailability mean a K2 label should keep the named menaquinone visible.

References

Source-checked local draft.
Human editorial review pending.

  1. NIH Office of Dietary SupplementsVitamin K: Fact Sheet for Health ProfessionalsChecked 2026-09-05
  2. European Food Safety AuthorityDietary Reference Values for nutrients: Summary reportChecked 2026-09-05
  3. U.S. Department of Agriculture, Agricultural Research ServiceFoodData Central Foundation Foods, April 2026 JSON releaseChecked 2026-09-05
  4. U.S. Department of Agriculture, Agricultural Research ServiceFoodData Central SR Legacy, April 2018 JSON releaseChecked 2026-09-05

Take it into the kitchen

Explore this nutrient in simple meals. Recipe pages show estimated amounts and missing data.

Banana & peanut oats · 8 min →

Berry yogurt oats · 5 min →

Apple & walnut porridge · 10 min →

All 40 easy meals →