Vitamin K

Does vitamin K2 stop calcium building up in the arteries?

Updated 3 Nov 2026

Short answer

Not consistently. A 2020 review of 9 trials found that vitamin K did not reliably slow calcium build-up, plaque or stiffening of the arteries.[1] A 2023 review found no slowing in 5 trials of vitamin K in people without kidney disease.[2] A 2026 trial found slower build-up with 360 µg of MK-7 a day for 2 years in people with coronary artery disease.[3]

Why the idea exists

  1. Matrix Gla protein (MGP) is found in the muscle of blood vessel walls, in bone and in cartilage.[4]
  2. MGP needs vitamin K to become active, and it may help stop calcium from settling in the vessel wall.[4]
  3. Calcium in the arteries makes them less elastic, and it is one of the risk factors for coronary heart disease.[4]
  4. In a Dutch study of 4,807 adults aged 55 and older, people who ate the most vitamin K2 had a 57% lower risk of dying of coronary heart disease. Vitamin K1 from food showed no such link. Studies of this kind show a link, not a cause.[4]

What the reviews found

  • A 2019 meta-analysis of 13 trials with 2,162 people found 9.1% less calcium build-up with vitamin K, but no clear effect on the stiffness of the arteries. Its authors said that the trials were few and their results varied a lot.[5]
  • A 2020 review of 9 trials found that vitamin K did not consistently slow calcium build-up, plaque or stiffening. There may be some benefit in people who already had calcium in their arteries.[1]
  • A 2023 review of 49 trials of many treatments, in people without kidney disease, found that the 5 trials of vitamin K consistently showed no slowing of calcium build-up.[2]

Single trials

  • Vitamin K1 in older adults. 388 healthy older adults took a multivitamin with or without 500 µg of vitamin K1 a day for 3 years. Calcium build-up in the coronary arteries did not differ overall. In those who already had calcium there, it grew 6% less with vitamin K1.[6]
  • MK-7 and stiff arteries. 244 healthy women after menopause took 180 µg of MK-7 or a placebo every day for 3 years. Their arteries became less stiff, most of all in women with stiff arteries at the start.[7]
  • MK-7 and the aortic valve. 365 men, aged 71 on average, with calcium in the aortic valve took 720 µg of MK-7 with 25 µg of vitamin D, or a placebo, for 2 years. Calcium in the valve rose by 275 units with MK-7 and by 292 units with placebo, a difference that could be due to chance. Calcium in the coronary arteries also did not differ.[8]
  • MK-7 in diabetes. 68 people with type 2 diabetes and heart or vessel disease took 360 µg of MK-7 or a placebo for 6 months. Calcium on CT scans did not change differently.[9]
  • MK-7 in coronary artery disease. 180 patients in the Netherlands with symptoms and some calcium in the coronary arteries took 360 µg of MK-7 or a placebo for 2 years. The median calcium score rose from 135 to 184 with MK-7 and from 145 to 214 with placebo, a significant difference. Whether this makes plaques more stable is not known yet.[3]

Heart attacks and strokes

A Cochrane review looked for trials of vitamin K alone to prevent heart disease. It found only 1 small trial of 60 people over 3 months, which did not count heart attacks or strokes. The review concluded that there is not enough evidence to say whether vitamin K prevents heart disease.[10] In the aortic valve trial, heart and vessel events were the same in both groups: 10 in each.[8]

Who should be careful

Vitamin K changes the effect of warfarin and similar blood thinners. People who take them should ask a doctor or pharmacist before they start vitamin K.[4] The authors of one study warned that 50 µg of MK-7 a day or more may change the effect of these medicines.[11]

Sources (11)

  1. Vitamin K Supplementation for the Prevention of Cardiovascular Disease: Where Is the Evidence? A Systematic Review of Controlled Trials. Vlasschaert C, Goss CJ, Pilkey NG, McKeown S, Holden RM Nutrients, 2020. PMID 32977548
  2. Interventions to Attenuate Cardiovascular Calcification Progression: A Systematic Review of Randomized Clinical Trials. Murali S, Smith ER, Tiong MK, Tan SJ, Toussaint ND J Am Heart Assoc, 2023. PMID 38014685
  3. Two Years of Menaquinone-7 Supplementation and Coronary Artery Calcification: A Randomized Clinical Trial. Vossen LM, de Leeuw PW, Schurgers LJ, Heuts S, Adriaans BP, de Haan C, et al. JAMA Cardiol, 2026. PMID 42268593
  4. Vitamin K: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  5. Vitamin K status, supplementation and vascular disease: a systematic review and meta-analysis. Lees JS, Chapman FA, Witham MD, Jardine AG, Mark PB Heart, 2019. PMID 30514729
  6. Vitamin K supplementation and progression of coronary artery calcium in older men and women. Shea MK, O'Donnell CJ, Hoffmann U, Dallal GE, Dawson-Hughes B, Ordovas JM, et al. Am J Clin Nutr, 2009. PMID 19386744
  7. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Knapen MH, Braam LA, Drummen NE, Bekers O, Hoeks AP, Vermeer C Thromb Haemost, 2015. PMID 25694037
  8. Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial. Diederichsen ACP, Lindholt JS, Möller S, Øvrehus KA, Auscher S, Lambrechtsen J, et al. Circulation, 2022. PMID 35465686
  9. The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial. Zwakenberg SR, de Jong PA, Bartstra JW, van Asperen R, Westerink J, de Valk H, et al. Am J Clin Nutr, 2019. PMID 31387121
  10. Vitamin K for the primary prevention of cardiovascular disease. Hartley L, Clar C, Ghannam O, Flowers N, Stranges S, Rees K Cochrane Database Syst Rev, 2015. PMID 26389791
  11. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Schurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C Blood, 2007. PMID 17158229

More about vitamin k

What is vitamin K?Which foods contain vitamin K?What is vitamin K used for?Who is at risk of vitamin K deficiency?Is vitamin K safe?Why do newborn babies get vitamin K?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.