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Vitamin K2 for Healthy Bones and Arteries

Apr 29, 2024 ● By Chuck Steinmann
A woman lifting a weight.

Photo credit Ashiq J/

Most people know that calcium and vitamin D are important for maintaining healthy bones. Fewer are aware of another vitamin that is essential for bone health, vitamin K2.

While vitamin D helps the body absorb calcium into the bloodstream, vitamin K2 gets calcium out of the blood and into the bones and teeth. Excess calcium in the blood can contribute to the formation of kidney stones or end up as deposits in breast tissue and arterial walls. By helping to get calcium where it belongs, K2 helps prevent calcium from ending up where it doesn’t belong. A review of 14 randomly controlled trials published in Frontiers in Nutrition found that K2 supplementation actually reverses calcification in the arteries. 

K2 can be found in red meat, aged hard cheese, egg yolks and fermented vegetables. The richest source of K2 is the Japanese fermented soy product natto. While eating foods rich in K2 is part of a healthy balanced diet, achieving therapeutic doses for bone health requires someone to eat natto or take supplements. Natto is famous for being an acquired taste, so most people decide to supplement.

K2 is most commonly available in two forms, MK-7 and MK-4. 

K2 MK-7 is more common and active at lower dosages, usually from 75 to 200 micrograms. Most K2 supplements are in this form, as are most D3/K2 combination supplements. K2 MK-7 is good for bones, but K2 MK-4 may be more effective at increasing bone density and reducing the risk of fractures, and has several studies to back it up.

K2 MK-4 has long been used by doctors in Japan to treat low bone density. MK-4 is given in doses much higher than MK-7, from 15 to 45 milligrams per day, with the most benefits being shown at the full 45 mg per day. A meta-analysis by Cokayne et al. published in the Archives of Internal Medicine analyzed 13 randomly controlled trials and found that 45 mg of K2 MK-4 helps maintain bone density and reduce the risk of fractures in the vertebrae and hip.

Bone density and strength tend to decline in everyone with age. According to the International Osteoporosis Foundation, one in three women and one in five men over 50 will experience a fracture due to a decrease in bone strength during their lifetime. Taking vitamin K2 is an important part of a plan to safely maintain healthy bones and keep calcium where it belongs. 

Chuck Steinmann is a health coach and manager of OsteoStrong, in Wilmette. OsteoStrong Wilmette is located at 126 Skokie Blvd. For more information, call 224-487-8833 or visit OsteoStrong Schaumburg is located at 195 W. Golf Rd. For more information, call 224-487-8881 or visit