First understand that there is Vitamin K1, associated with blood coagulation, and Vitamin K2, which is described here. Two of the major health concerns of our times occur because of calcium deficiency in the skeleton and excess calcium in the arteries, which are both underlying factors in osteoporosis and heart disease. Vitamin K2 is the key to putting calcium back in its place to help avoid these situations.
Osteoporosis is the loss of bone mineral density and thinning of bone tissue, causing bones to be more porous and prone to fracture. It occurs when there is imbalance between the formation of new bone and old bone resorption. Since osteoporosis is characterized by lack of calcium in the bones, adequate calcium intake is the most important remedy. Atherosclerosis is a buildup of calcium-laden plaque that clogs the arteries. The clogged arteries can lead to heart attacks. If you’re getting plenty of calcium from food sources or supplements, it’s vitally important that the calcium is getting where it needs to go instead of gathering in the arteries, contributing to heart disease.
Let’s look a few other vitamins and minerals important to bone health. Vitamin D3 increases absorption of calcium from intestines which is good for bone health. Magnesium is essential for the absorption and metabolism of Vitamin D3. Calcium and Vitamin D3 together have been shown to increase bone density better than either one alone. Once calcium is absorbed into the bloodstream, Vitamin D3 has no power over what happens to it, but Vitamin K2 puts calcium in its place. When vitamin D3 is lacking, K2 can’t do its job of escorting calcium away from arteries and into bones.
How K2 works is that it activates proteins in the body that move the calcium around, in particular one called osteocalcin, which moves calcium into bones and teeth where it’s needed. The other protein K2 activates is matrix GLA protein (MGP), which sweeps calcium out of soft tissues like arteries and veins where calcium is harmful. Without K2, these proteins aren’t activated. You can see that when K2 is plentiful, bone mineral density can be improved and arteries can remain clear.
Vitamin A is another piece of this puzzle. Its role in bone health is that it increases the number and activity of osteoclast cells which break down bone tissue. This is how old, weakened bone tissue is removed to make room for new, stronger bone tissue and is critical to fracture repair and bone density retention. Vitamin A is also involved in stimulating bone-building cells called osteoblasts to secrete proteins like osteocalcin that are necessary for bone mineralization.
You can see how vitamin K2 is critical to bone and heart health and it partners with vitamins A and D3 to perform at its optimal level. Foods rich in K2 are natto (fermented soy), followed distantly by goose liver pate and even more distantly by hard cheeses and therefor difficult to get in our diets. Fortunately it’s available in supplement form from natto.
Source: Vitamin K2 & the Calcium Paradox by Dr. Kate Rheaume-Bleue, BSc, ND.