Overshadowed by fish oil supplements, vitamin D, and other nutrients, vitamin K doesn’t have to play second fiddle to any nutrient. Vitamin K has many important health benefits.
Vitamin K keeps calcium in the bones and prevents calcium from building up in blood vessels (hardening of the arteries). It also reduces the risk of some cancers, improves bone fracture healing, and can limit joint changes related to rheumatoid arthritis. Vitamin K is probably best known for its role in the clotting of blood.
Types of Vitamin K
There is more than one type of vitamin K. There is K1, K2, and even a K3. Most of us are familiar of K1. Even many doctors are unaware that there is more than one vitamin K. So what are the vitamin K foods? K1 is found in leafy green vegetables while K2 is found in organ meats, egg yolks, dairy products, and cheese.
K2 is better absorbed by the body than is K1. And, it is K2 that really protects our bones and prevents calcium from building up in the walls of our blood vessels.
Vitamin K and Warfarin
Warfarin interferes with vitamin K function and is a drug that is prescribed to prevent blood clots. Patients taking warfarin are more likely to develop osteoporotic fractures and more likely to develop hardening arteries and develop calcium deposits of the valves of the heart. This is the result of having vitamin K deficiency caused by warfarin. While warfarin prevents blood clots it has a harmful effect on the bones and heart.
How Does Vitamin K2 Work?
Our bone is constantly turning over – this is the body’s way of ensuring that our bone is strong and resilient. First, some bone is dissolved or reabsorbed. This is done under the direction of cells call osteoclasts. Then osteoblasts stimulate new bone formation. They do this by producing a protein called osteocalcin that allows new calcium to be laid down.
Vitamin K2 inhibits osteoclasts and K2 facilitates osteocalcin to bind calcium. Vitamin D by the way is needed for the osteoblasts to produce osteocalcin. Data from the Framingham Heart Study showed that individuals with vitamin K intake in the top quartile had a 65% lower risk of hip fractures than those whose dietary vitamin K intake was in the bottom quartile.
A Japanese study found the vitamin K2 was just as effective as the prescription drug etidronate (a bisphosphonate) in preventing vertebral fractures. And, individuals who took both etidronate and vitamin K2 experience half as many vertebral fractures compared to those who took only etidronate or only vitamin K2.
Atherosclerosis occurs when the inner lining of blood vessels called the endothelium is injured leading to the production of collagen to cap the injured area. Calcium tends to accumulate in these collagen caps leading to hardening of the arteries. This raises the risk of heart attacks. Calcium can also deposit in the valves of the heart damaging them slowly over time.
So by keeping calcium in the bone vitamin K2 indirectly reduces the calcium available to build up in the arteries and valves of the heart.
Preventing Cancer an Added Benefit of Vitamin K2
Vitamin K2 causes apoptosis, or programmed cell death in some cancers. It inhibits nuclear factor-kappa B (NFkB), the master regulator of inflammation. NFkB is turned on in cancer cells, but vitamin K2 helps to shut it off.
One warning: if you take warfarin be sure to ask your doctor before supplementing with vitamin K as vitamin K counteracts the effects of warfarin.
See related articles.