Flow IV: Vitamin K, Your Bones and Your Arteries, with JE Block, MD, PhD

J.E. Block, MD, PhD, FACP

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Job Title / Position: Medical Director, Health Educator

Website: Integrative and Internal Medicine Center

Contact Information:  918-591-3891


View Dr Block’s Video Presentation on Vitamin K  here.

Vitamin K gives protection against arterial calcification, Alzheimers, bone loss, cancer, and even aging! Although discovered in 1929, both Edward Adelbert Doisy (who died in1986), an American biochemist, along with his Danish colleague, Henrik Dam received the Nobel Prize in Physiology Medicine in 1943.  The new vitamin received the letter K because the initial work was reported in a German journal, in which it was designated as Koagulationsvit (K from “Koagulations”).  However, this fat soluble vitamin, in light of the last decade of research, has been shown to do much more than coagulate patients who have a low amount of activated clotting factors, such as occurs in people who take the drug warfain (Coumadin), poor intestinal flora, malnutrition, or impaired liver function.

Normally, as one ages, calcification of soft tissues throughout the body such as heart valves, cornea, glands, and blood vessels occurs. Autopsies report 75% of folks over 75 have significant calcification and dysfunction of these organs! Dietary calcium is not the culprit causing this problem. The reason for this contradiction is that in response to a deficit of calcium in the blood, the parathyroid gland produces more of its hormone (PTH), which robs our bones and saturates soft tissues with calcium.  Magnesium decreases the PTH output and counteracts the calcium bone loss. The action of vitamin K in the body is to carboxylate proteins. Carboxylation is an addition of a carboxyl group into a compound or molecule. When a protein is carboxylated, it undergoes a chemical conversion that changes its function. Vitamin K maintains normal coagulation, preserves bone, and protects against calcification by carboxylating specific proteins in the body. In the arteries, vitamin K is required to carboxylate matrix Gla-protein. If Matrix Gla-Protein (MGP) is under-carboxylated, then it is unable to perform its normal role in protecting arteries against excess accumulation of calcium, or inhibiting vascular calcification. Matrix Gla-protein is a calcification inhibitor that requires sufficient vitamin K to function optimally. The effect of vitamin K in carboxylating matrix Gla-protein is how it protects against arterial calcification.

Atherosclerosis is the leading cause of disability and death in civilized societies. Many factors are involved in its initiation and progression to include elevated blood pressure, sugar, uric acid, lipids, fibrinagen, Plac-2, Lp(a), MPO, homocysteine,  smoking, kidney disease, and even non specific inflammation. These initially damage the inner arterial lining (the endothelium). To repair this damage, the endothelium produces collagen that contains MGA which forms a cap and macrophages that entrap oxidized cholesterol within the injury.

These endothelial collagen caps with their underlying cholesterol burden attract calcium through the MGP mechanism that subsequently accumulates calcium which forms a hard material resembling bone. This is why atherosclerosis is referred to as “hardening of the arteries.” Atherosclerosis is the soft plaque before it becomes harden with calcium.  Whether MPG allows or prevents calcification depends on its state of carboxylation. It is Vitamin K that carboxylates the MGP and inhibits calcification. Not enough Vitamin K, then calcium is deposited. Calcification of the coronary arteries markedly increases the risk of myocardial infarction and heart failure. The same process takes place in our heart valves as we age particularly the aortic, which in addition to the other risk factors noted above has the highest pressure for the thinnest tissue of any place in the body.

A substantial volume of studies shows that different tissues need varying amounts of carboxylation for complete saturation  and only minimal amounts of  Vitamin K is needed to carboxylate (activate) the clotting factors. But much more is needed to inhibit MGA from calling in calcium to the “injured” site. So, insufficient vitamin K2 accelerates arterial calcification. A recent study shows that restoring to high levels of vitamin Kreverses arterial and valvular calcification.

Jack LaLanne was an expert in all things health to include nutrition, but the science was not yet ready when in 2003, he published his last book, “Revitalize Your Life.” He used the precepts of the book to maintain his health, but his diet and supplements did not have enough Vitamin K. Due to this, genetics and his age, he developed Aortic Stenosis, and unfortunately was talked into valve replacement in 2009. This started his downhill spiral that twelve and a half months later eventuated in his death at age 96.

Vitamin K is as important in bone health as is Vitamin D. Bone is living tissue that is in a constant state of renewal. The maintenance of bone first requires old bone to be dissolved by cells called “osteoclasts.” When the activity of osteoclasts is too high, large holes develop that weaken the bone and lead to osteoporosis. Vitamin K2 is a key to turning off excess osteoclast activity and bone degradation.

The holes left by osteoclasts are prepared for remodeling by osteoblast cells. The osteoblasts secrete a protein called osteocalcin, the synthesis of of which requires vitamin D3.  But it needs to be  activated (or carboxylated) by Vitamin K for new calcium to be laid down into the bone.

To reiterate, the calcium-binding properties of osteocalcin require vitamin K for two critical processes to the bone. It first protects against excess bone degradation (resorption) by turning off excess osteoclast activity. It then supports new bone formation by enabling osteocalcin to pull calcium from the blood and layer it on to the bone. Maintenance of healthy bone density requires adequate levels of magnesium, calcium, strontium and Vitamins D, C, and K. Without vitamin D, there will be no osteocalcin for vitamin K to work on. Without vitamin K, the osteocalcin that is produced will be inactive. And of course without calcium (and other minerals), there will be no minerals for the activated osteocalcin to attract to the bone for structural density.

The Nurses’ Health Study followed more than 72,000 women for 10 years and found that women whose vitamin K intakes were in the lowest quintile (1/5) had a 30% higher risk of hip fracture than women with vitamin K intakes in the highest four quintiles. Another (seven-year) study in over 888 elderly men and women (Framingham Heart Study) found that men and women with dietary vitamin K intakes in the highest quartile (1/4) had a 65% lower risk of hip fracture than those with dietary vitamin K intakes in the lowest quartile (approximately 254 micrograms/day vs. 56 micrograms/day of vitamin K).  In Japan, it is approved by prescription to treat Osteoporosis.

Vitamin K has been proven to be beneficial for prevention and even the treatment of several cancers. These include Lung, Pancreas, GI, Breast, Bladder, Liver, Leukemia and particularly the Prostate.  Doctors in Germany conducted a study examining the relationships between dietary intake of vitamin K1 and K2 on the development of prostate cancer in 11,319 men over an 8.6-year follow-up. Compared with the lowest intake of vitamin K2, men with the highest vitamin K2 dietary consumption showed a 63% reduced incidence of advanced prostate cancer. Intake of vitamin K1 was not related to prostate cancer incidence in this 2008 study. Apatone® is a drug consisting of vitamin C and vitamin K3. It has been granted orphan drug status by the FDA to treat advanced bladder cancer

Vitamin K is actually a group that includes two natural “vitamers,” vitamin K1 and vitamin K2.  Vitamin K1 is phylloquinone or phytomenadione (also called phytonadione).  K1 is synthesized by plants and is found in green leafy vegetables and can be found in soybean oil. Vitamin K2 homologs (menaquinones) are characterized by the number of isoprene side chains. These are produced in the intestine from the plant derived K1.  Thesemenaquinones are abbreviated MK-n (n represents the number of the side chains). Thus,Menaquinone (Vitamin) K-4 abbreviated MK-4, has 4 side chains. Three synthetic types of vitamin K have been made and patented. These are vitamins K3, K4, and K5. Although the natural K1 and K2 forms are safe, the synthetic form K3(menadione) has shown toxicity.  Vitamin K2 shows numerous advantages over vitamin K1, including better absorption, longer lasting and increased protection against heart disease The MK-4 and MK-7 forms of vitamin K2 have demonstrated important health benefits in numerous studies. While the MK-4 form has been shown to support cardiovascular and bone health, the MK-7 form is exceptionally long acting and reaches higher levels in the blood. Therefore, when taking a Vitamin K supplement, not only the dose, but the specific subtype is very important.

  • Individuals who use Coumadin® have long been advised to avoid vitamin K, and as a result, they may suffer increased atherosclerosis and osteoporosis. Under a doctor’s supervision, vitamin K can help stabilize blood indicators of coagulation in Coumadin® users while conferring other health benefits.
  • By preventing pathological tissue calcification, vitamin K may confer anti-aging effects throughout the body. Higher vitamin K intake has also been associated with reduced all-cause mortality.

Daily supplementation with vitamin K1 and K2 (in both the MK-4 and MK-7 forms) is crucial for vascular health, bone health, and cancer protection.

Vitamin K2 has proven to be as effective as prescription drugs in reducing the incidence of bone fractures. A Japanese study in postmenopausal women compared the effect of K2 (MK-4) with the drug etidronate (Didronel®) on the incidence of vertebral (spine) fracture. Women taking K2 at a dose of 45 mg per day experienced a fracture rate of 8.0% compared with 8.7% for those taking the etidronate drug therapy. Furthermore, women taking both MK-4 and the drug experienced only a 3.8% fracture rate. In a placebo group that received neither K2 nor drug therapy, nearly 21% of women experienced bone fractures.