But there is also evidence that vitamin K, and specifically vitamin K2, is another key player in your bone health, and may be just as crucial in helping you prevent bone fractures as you age.
Vitamin K1 and K2: Which is Better for Your Bones?
In case you weren’t aware, vitamin K comes in two forms, and it is important to understand the differences between them before devising your nutritional plan of attack.
Vitamin K1: Found in green vegetables, K1 goes directly to your liver and helps you maintain a healthy blood clotting system. (This is the kind of K that infants need to help prevent a serious bleeding disorder.)
Vitamin K2: Bacteria produce this type of vitamin K. It is present in high quantities in your gut, but unfortunately is not absorbed from there and passes out in your stool. K2 goes straight to vessel walls, bones, and tissues other than your liver.
There are several different forms of vitamin K2: MK4, MK7, MK8, and MK9. The form of vitamin K that has the most relevance for health benefits is MK7, a newer and longer acting form with more practical applications. MK7 is extracted from the Japanese fermented soy product called natto. You could actually get plenty of MK7 from consuming natto, as it is relatively inexpensive and available in most Asian food markets.
Few people, however, easily tolerate its smell and slimy texture, so oftentimes people who find natto unpalatable prefer to take a supplement. Most vitamin K2 supplements are in the form MK7. You can also get MK7 by eating fermented cheeses. There has been some remarkable research about the protective effects of vitamin K2 against osteoporosis:
- A number of Japanese trials have shown that vitamin K2 completely reverses bone loss and in some cases even increases bone mass in people with osteoporosis.
- The pooled evidence of seven Japanese trials show that vitamin K2 supplementation produces a 60 percent reduction in vertebral fractures and an 80 percent reduction in hip and other non-vertebral fractures.
- Researchers in the Netherlands showed that vitamin K2 is three times more effective than vitamin K1 in raising osteocalcin, which controls the building of bone.
Why Vitamin K is So Important if You Take Calcium and Vitamin D ?
If you currently take calcium and vitamin D for your bones, it’s important that you also get plenty of vitamin K2. These three nutrients have a synergistic effect that cannot be achieved when one piece of the puzzle is missing. Specifically, here’s a simple explanation of why the benefits of calcium and vitamin D are largely dependent on vitamin K:
Calcium: There is new evidence that it is vitamin K (specifically, vitamin K2) that directs calcium to your skeleton, while preventing it from being deposited where you don’t want it — i.e., your organs, joint spaces, and arteries. A large part of arterial plaque consists of calcium deposits (atherosclerosis), hence the term “hardening of the arteries.”
Vitamin K2 activates a protein hormone called osteocalcin, produced by osteoblasts, which is needed to bind calcium into the matrix of your bone. Osteocalcin also appears to help prevent calcium from depositing into your arteries. So while increasing calcium is good for your bones, it is not so good for your arteries, which can become calcified. Vitamin K helps protect your blood vessels from calcifying when in the presence of high calcium levels.
Vitamin D3: As mentioned, vitamin D helps your body to absorb calcium, but vitamin K directs that calcium to your skeleton where it’s needed. You can think of vitamin D as the gatekeeper, controlling who gets in, and vitamin K as the traffic cop, directing the traffic to where it needs to go. Lots of traffic — but no traffic cop — means clogging, crowding and chaos everywhere!
In other words, without the help of vitamin K2, the calcium that your vitamin D so effectively lets in might be working AGAINST you — by building up in your coronary arteries rather than your bones. There is even evidence that the safety of vitamin D is dependent on vitamin K, and that vitamin D toxicity (although very rare with the D3 form) is actually caused by vitamin K2 deficiency.
