Life Extension Magazine®
Man jogging for cardiovascular health with a boost with vitamin K2

Vitamin K2: Heart Health Benefits

Older adults with the high­est vitamin K2 intake had a sharply lower risk of death from coronary heart disease.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in May 2022. Written by: Anthony Payne, N.M.D., Ph.D., M.D. (honorary).

Vitamin K2 is best known for helping to build strong, healthy bones.

Some of the same skeletal benefits make it a powerful protector of the cardiovascular system.1

Cardiovascular disease is the leading killer in the U.S.2 Vitamin K2 may help to:1,3

  • Reduce arterial stiffness,
  • Slow the progression of arterial and valve calcification,
  • Lower the incidence of diabetes, and
  • Decrease cardiovascular mortality.

In one study, adults 55 and older were followed for up to 10 years. Those with the highest intake of vitamin K2, compared to the lowest, had a 57% lower risk of death from coronary heart disease—and a 26% lower risk of death from any cause.4

About Vitamin K

There are two main types of vitamin K.5

Vitamin K1 is primarily found in green leafy vegetables. It has long been used to promote healthy blood clotting and prevent abnormal bleeding.5

Vitamin K2 is also known as menaquinone. It is essential for the health of bones and the cardiovascular system. Emerging evidence indicates it may play a vital role in immune function and in the health of the nervous system.1

Vitamin K2 exists in several forms. Among these,menaquinone-4 (MK-4) and menaquinone-7 (MK-7) have been studied most extensively.6,7

MK-4 is found mainly in dairy foods. MK-7 is primarily found in fermented foods, such as kefir (fermented milk) and sauerkraut.5,8

Preventing Atherosclerosis

In the U.S., over 650,000 people die from heart disease each year. That’s roughly one in every four deaths.2

More than half of these deaths are from coronary artery disease, caused by a buildup of plaque (made of fats, calcium, and other substances) in the walls of arteries that restricts blood flow.2

This buildup is known as atherosclerosis. It can result in chest pain, heart attacks, and strokes.9,10

Daily oral intake of vitamin K2 may prevent atherosclerosis from progressing.

Last year, the American Heart Association released research showing that higher vitamin K intake was associated with significantly lower risk of hospitalizations resulting from atherosclerotic cardiovascular disease.11

Combating Arterial Stiffness

One of the most significant ways vitamin K2 protects against cardiovascular disease is by preventing arterial stiffness.

This physical stiffening of arteries contributes to cardiovascular disease.12

Vitamin K2 activates matrix Gla, a protein that helps prevent calcium from being incorporated into arterial tissue.1

It also activates another protein that binds calcium to bone. This strengthens bone while at the same time helping to prevent calcification of our arteries.

Protecting Endothelial Function

All blood vessels are lined with a very thin layer of cells called the endothelium. This tissue helps regulate the flow of calcium and other substances into and out of the bloodstream.13,14

A healthy endothelium is needed for optimal cardiovascular health.15

Endothelial dysfunction is a major contributor to aging, atherosclerosis, hypertension, and the complications of diabetes.15

It is characterized by an imbalance in the constriction and relaxation (dilation) of arteries, a decrease in nitric oxide bioavailability, and an increase in reactive oxygen species and pro-inflammatory factors.15

A hallmark of many types of cardiovascular disease is endothelial dysfunction.

When endothelial cells cannot function properly, plaque builds up and calcifies, and narrows the artery.16

Vitamin K provides cardiovascular protection thanks to its role in calcium homeostasis.

In a preclinical study, giving vitamin K2 to mice prone to developing atherosclerosis increased nitric oxide production. This improved the ability of arteries to dilate.17

A 2021 review published in Open Heart Journal stated that:

“Increased vitamin K2 intake may reduce arterial stiffness, slow progression of vascular and valvular calcification, lower the incidence of diabetes and coronary artery disease, and decrease cardiovascular mortality.”3

Real-World Results

The heart-protective effects of vitamin K2 have been demonstrated in multiple studies.

In observational studies, higher intakes of vitamin K2 were associated with lower rates of arterial calcification and death from coronary artery disease.18

In one study, women with the highest K2 intake were found to be at a 20% lower risk for coronary artery calcification than women who had the lowest intake.19

Researchers analyzing more than 16,000 Dutch women who were followed for an average of 8.1 years found that each 10 mcg/day increase in vitamin K2 intake was associated with a 9% reduction in coronary heart disease risk.20

In another study, researchers followed more than 4,800 adults over age 55 for up to 10 years.4

Overall, those with the highest K2 intake had a 57% lower rate of death due to coronary heart disease and a 26% lower rate of death from any cause.4

Safety of High-Dose Vitamin K2

Research suggests that higher doses of vitamin K2 intake are most likely to prevent the development or progression of cardiovascular disease.

In clinical studies involving daily K2 doses ranging from 10 mcg to 135 mg, there have been no reports of adverse side effects.21 (The vitamin K2 dose of 135 mg is very high by historic standards, yet no toxicity was observed.)

What you need to know

Protecting the Heart with Vitamin K2

  • Cardiovascular disease is the leading cause of death in the U.S. It is frequently driven by atherosclerosis, buildup of plaque in arteries.
  • Vitamin K2 can help prevent and reduce calcification in arteries. It also reduces endothelial dysfunction, further decreasing atherosclerosis risk.
  • In observational studies, those with the highest intake of vitamin K2 have lower rates of heart disease and as much as a 57% lower rate of death due to coronary heart disease.

Japanese doctors routinely prescribe 45 mg of vitamin K2 daily to women with osteoporosis.21,22

These amounts may also help prevent the progression of atherosclerosis.

Summary

Vitamin K2 helps prevent arterial stiffening, buildup of plaque in artery walls, and endothelial dysfunction.

These and other actions reduce the development and progression of atherosclerosis, a major cause of heart disease.

A Warning About Warfarin

Anyone taking the anticoagulant drug warfarin should consult a physician before taking any form of vitamin K.

That’s because warfarin interferes with the action of vitamin K in the body. Those taking newer anticoagulant drugs such as Eliquis®, Pradaxa®, and Xarelto® do not need to restrict vitamin K intake.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

References

  1. Halder M, Petsophonsakul P, Akbulut AC, et al. Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease. Int J Mol Sci. 2019 Feb 19;20(4):896.
  2. Available at: https://www.cdc.gov/heartdisease/facts.htm. Accessed April 12, 2022.
  3. Hariri E, Kassis N, Iskandar JP, et al. Vitamin K2-a neglected player in cardiovascular health: a narrative review. Open Heart. 2021 Nov;8(2):e001715.
  4. Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004 Nov;134(11):3100-5.
  5. Shioi A, Morioka T, Shoji T, et al. The Inhibitory Roles of Vitamin K in Progression of Vascular Calcification. Nutrients. 2020 Feb 23;12(2).
  6. Walther B, Karl JP, Booth SL, et al. Menaquinones, bacteria, and the food supply: the relevance of dairy and fermented food products to vitamin K requirements. Adv Nutr. 2013 Jul 1;4(4):463-73.
  7. Marles RJ, Roe AL, Oketch-Rabah HA. US Pharmacopeial Convention safety evaluation of menaquinone-7, a form of vitamin K. Nutr Rev. 2017 Jul 1;75(7):553-78.
  8. Schwalfenberg GK. Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health. J Nutr Metab. 2017;2017:6254836.
  9. Available at: https://www.ncbi.nlm.nih.gov/books/NBK507799/. Accessed April 12, 2022.
  10. Available at: https://www.cdc.gov/heartdisease/coronary_ad.htm. Accessed April 14, 2022.
  11. Bellinge JW, Dalgaard F, Murray K, et al. Vitamin K Intake and Atherosclerotic Cardiovascular Disease in the Danish Diet Cancer and Health Study. J Am Heart Assoc. 2021 Aug 17;10(16):e020551.
  12. Hansen L, Taylor WR. Is increased arterial stiffness a cause or consequence of atherosclerosis? Atherosclerosis. 2016 Jun;249:226-7.
  13. Rajendran P, Rengarajan T, Thangavel J, et al. The vascular endothelium and human diseases. Int J Biol Sci. 2013;9(10):1057-69.
  14. Plank MJ, Wall DJ, David T. Atherosclerosis and calcium signalling in endothelial cells. Prog Biophys Mol Biol. 2006 Jul;91(3):287-313.
  15. Sun HJ, Wu ZY, Nie XW, et al. Role of Endothelial Dysfunction in Cardiovascular Diseases: The Link Between Inflammation and Hydrogen Sulfide. Front Pharmacol. 2019 2020-January-21;10:1568.
  16. Xu S, Ilyas I, Little PJ, et al. Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies. Pharmacol Rev. 2021 Jul;73(3):924-67.
  17. Bar A, Kus K, Manterys A, et al. Vitamin K2-MK-7 improves nitric oxide-dependent endothelial function in ApoE/LDLR(-/-) mice. Vascul Pharmacol. 2019 Nov - Dec;122-123:106581
  18. Knapen MH, Braam LA, Drummen NE, et al. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Thromb Haemost. 2015 May;113(5):1135-44.
  19. Beulens JW, Bots ML, Atsma F, et al. High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis. 2009 Apr;203(2):489-93.
  20. Gast GC, de Roos NM, Sluijs I, et al. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10.
  21. Akbulut AC, Pavlic A, Petsophonsakul P, et al. Vitamin K2 Needs an RDI Separate from Vitamin K1. Nutrients. 2020 Jun 21;12(6).
  22. Iwamoto J. Vitamin K(2) therapy for postmenopausal osteoporosis. Nutrients. 2014 May 16;6(5):1971-80.