What Foods Are High in Vitamin K2? Natto, Cheese, Eggs and the Rest

The food highest in vitamin K2 is natto, the Japanese fermented soya bean, at roughly 1,000 to 1,100 micrograms per 100 g, more than ten times anything else. Then come hard cheeses at about 25 to 75 micrograms per 100 g, soft cheeses 12 to 68, egg yolk, chicken, liver and butter in the tens of micrograms or below, and sauerkraut in traces.^{1, 2} The UK sets no separate K2 requirement: K1 and K2 count towards the same intake of about 1 microgram per kilogram of body weight a day, and vitamin K contributes to the maintenance of normal bones and to normal blood clotting in either form.³

• Richest by far: natto (MK-7); one 40 g pack supplies about 400 micrograms
• Everyday sources: hard and soft cheese, egg yolk, chicken, liver, butter
• Not sources: bananas, almonds, fruit and vegetables generally; sauerkraut only traces
• Warfarin: keep intake steady rather than avoiding it; tell your anticoagulant clinic before adding natto or a supplement

Vitamin K1 or K2: what is the difference?

Vitamin K1, phylloquinone, is the plant form in kale, spinach and broccoli, and supplies most of the vitamin K the UK eats. Vitamin K2 is a family of menaquinones, MK-4 to MK-13. MK-4 is made by animals, including us, from a little of the K1 we eat, and sits in egg yolk, meat and dairy fat; MK-7 and the longer forms are made by bacteria, so they turn up where bacteria have been at work, in natto and in ripened cheese.^{1, 2} MK-7 stays in the blood longer than K1 or MK-4, which is why most supplements use it.

Vitamin K2 foods table

Composition data for K2 is thin and varies by cheese, animal feed and batch, so every figure is approximate.^{1, 2}

Natto: the richest source

Natto is soya beans fermented with a bacterium that makes MK-7 as it grows, and one 40 g pack carries more K2 than a fortnight of cheese. It is sticky, strong-smelling and an acquired taste, sold frozen in Japanese and Korean grocers in the UK. The MK-7 bone trials used 180 to 360 micrograms a day, roughly half a pack to a pack.^{4, 5}

Cheese, dairy, eggs, meat and liver

Cheese is the everyday K2 source in a British diet. A 2018 analysis of 35 cheeses found most K2 in aged hard cheeses and some soft ripened ones, least in fresh curd, Parmesan and feta; 30 g of Cheddar gives about 7 micrograms and 30 g of Gouda about 20, a tenth to just over a quarter of a day's vitamin K for a 70 kg adult.² Egg yolk carries MK-4 at about 30 micrograms per 100 g, which is about 5 micrograms a yolk, so "free-range yolks are a rich K2 boost" overstates it.¹ Chicken thigh and leg hold about 10 micrograms per 100 g, liver varies from about 2 micrograms in pig liver and 11 in beef liver to hundreds in goose liver paste, and butter contributes a little through its fat.

Vegan sources of vitamin K2

Natto is the only plant food with a meaningful amount of vitamin K2; sauerkraut, kimchi, tempeh and miso hold a few micrograms at most. A vegan diet is rich in K1 from greens, which meets the UK intake and partly converts to MK-4, so vegans are not short of vitamin K, only of K2. A vegan K2 supplement supplies MK-7, the natto form, often at 75 micrograms, the UK nutrient reference value for vitamin K, and usually paired with vitamin D3; vitamin K contributes to the maintenance of normal bones and to normal blood clotting, and vitamin D contributes to the maintenance of normal bones and to the normal absorption of calcium. The bone trials below used 180 to 360 micrograms.

How much vitamin K do you need?

About 1 microgram a day per kilogram of body weight, so 70 micrograms for a 70 kg adult, according to the NHS; any diet with green vegetables meets that, and 1 mg or less a day from supplements is unlikely to cause harm.³ No UK or European body sets a separate K2 intake. Vitamin K deficiency is rare in adults who absorb food normally and shows as easy bruising and bleeding.

What does vitamin K2 do, and does it route calcium to bones?

Vitamin K contributes to the maintenance of normal bones and to normal blood clotting, because liver and bone use it to activate proteins, including osteocalcin in bone. The popular extension, that K2 "sends calcium to the bones and keeps it out of the arteries", is a hypothesis built on a real protein, matrix Gla protein, which needs vitamin K to inhibit calcification, and on Dutch cohorts in which people eating the most K2 had fewer heart deaths.⁶ The trials have not borne it out. In Japan, MK-4 at 45 mg a day, a prescription dose six hundred times the reference value, reduced fractures in small trials but not in the 4,378-woman trial run to confirm them.⁷ In Western women taking 180 to 360 micrograms of MK-7 for one to three years, one trial found slower bone loss, another found no difference in bone density, and the latest systematic review found no evidence that vitamin K affects bone density or spinal fractures and only uncertain evidence on other fractures.^{4, 5, 8} On arteries, 360 micrograms of MK-7 a day for six months did not slow calcification in people with diabetes, and 720 micrograms with vitamin D for two years did not slow aortic valve calcification.^{9, 10} An attractive mechanism, supportive observational data, null or mixed trials; no artery or calcium-routing claim is authorised in Great Britain.

Do you need K2 with D3?

No. Vitamin D3 does its work on calcium absorption and bone whether or not K2 is alongside, and vitamin D's authorised wording stands on its own; vitamin K has its own bone wording for its own reasons. Taking the two together is convenient and harmless, but D3 does not "need" K2. Vitamin D3 and K2 covers the pairing and the vitamin D upper limit; do you need a calcium supplement covers the calcium side.

Vitamin K2 foods and warfarin

Warfarin works by blocking vitamin K, so a sudden change in intake, up or down, moves the INR the anticoagulant clinic monitors. The advice is consistency, not avoidance: eat the greens and cheese you normally eat in the amounts you normally eat them, and tell the clinic before adding or dropping a big source.¹¹ Natto can swing an INR on its own, because one pack carries several times a day's vitamin K as long-lasting MK-7, and so can any K2 supplement, which is why the D3 and K2 gummies carry an anticoagulant warning. Apixaban, rivaroxaban, edoxaban and dabigatran do not work through vitamin K. Your clinic sets any adjustment.

Frequently asked questions

What food is highest in vitamin K2?

Natto, at roughly 1,000 to 1,100 micrograms per 100 g; a 40 g pack gives about 400 micrograms. Hard cheese, the next tier, holds about 25 to 75 micrograms per 100 g.^{1, 2}

Which foods are naturally high in vitamin K2?

Natto, aged cheeses, egg yolk, chicken, liver and butter.

Do bananas or almonds have vitamin K2?

No. Bananas have almost no vitamin K of any kind, almonds a trace of K1 and no K2; among plant foods only natto has K2 in quantity.

What are the signs of vitamin K2 deficiency?

There is no recognised K2 deficiency syndrome; vitamin K deficiency as a whole shows as easy bruising and bleeding, is rare in adults who absorb food normally, and is a reason to see a GP.³

Is it safe to take vitamin K2 every day?

For most people yes; the NHS says 1 mg or less a day from supplements is unlikely to cause harm.³ Anyone on warfarin or a related anticoagulant should not start one without their clinic's agreement.

Who should avoid vitamin K2?

People taking warfarin or another coumarin anticoagulant, unless their clinic has agreed and will monitor the INR, and anyone a doctor has told to limit vitamin K.¹¹

Should seniors take vitamin K2?

Not as a rule: older adults need the same vitamin K per kilogram as everyone else, most get it from food, and the MK-7 bone trials were mixed. Can you rebuild bone density sets out what moves bone density in later life; the Wellgard joint health guide covers the joints.

Sources

1. Schurgers LJ, Vermeer C. Determination of phylloquinone and menaquinones in food: effect of food matrix on circulating vitamin K concentrations. Haemostasis, 2000. PubMed 11356998.
2. Vermeer C, et al. Menaquinone content of cheese. Nutrients, 2018. PubMed 29617314.
3. NHS. Vitamin K: vitamins and minerals. nhs.uk; Great Britain nutrition and health claims register. gov.uk.
4. Knapen MH, et al. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporosis International, 2013. PubMed 23525894.
5. Emaus N, et al. Vitamin K2 supplementation does not influence bone loss in early menopausal women: a randomised double-blind placebo-controlled trial. Osteoporosis International, 2010. PubMed 19937427.
6. Geleijnse JM, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Journal of Nutrition, 2004. PubMed 15514282.
7. Inoue T, et al. Randomized controlled study on the prevention of osteoporotic fractures (OF study): a phase IV clinical study of 15-mg menatetrenone capsules. Journal of Bone and Mineral Metabolism, 2009. PubMed 19082528.
8. Mott A, et al. Effect of vitamin K on bone mineral density and fractures in adults: an updated systematic review and meta-analysis of randomised controlled trials. Osteoporosis International, 2019. PubMed 31076817.
9. Zwakenberg SR, et al. The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial. American Journal of Clinical Nutrition, 2019. PubMed 31387121.
10. Diederichsen ACP, et al. Vitamin K2 and D in patients with aortic valve calcification: a randomized double-blinded clinical trial. Circulation, 2022. PubMed 35465686.
11. NHS. Warfarin. nhs.uk.

This article is general information, not medical advice. If you take warfarin or another anticoagulant, speak to your anticoagulant clinic before changing how much natto, cheese or green vegetables you eat or before starting a vitamin K supplement.