Of all the benefits of Vitamin K2, the one that shows the most promise and about which there is the least modern research is dental health. Working independently, Dr. Weston Price and his contemporaries showed that it was possible to not just prevent but to also heal active dental cavities with diet, and yet this research fell into obscurity. Ensuring adequate Vitamin K2 was a cornerstone of the nutritional protocol to treat cavities and it drills holes in our modern understanding of what really causes cavities and how to treat them.
          The tooth is made of four parts (see the diagram below).  The soft innermost layer is called the pulp. It houses blood vessels connected to the body’s circulatory system and sensitive nerves. Below the gum line is the tooth’s root; above the gum line is the crown. The pulp is surrounded by dentin, a calcified, bonelike matrix made up of millions of tiny, closely packed tubules. In the root, the dentin is covered by cementum, a thin layer of mineralized tissue. In the crown, the dentin is covered by enamel, the white portion of tooth we can see.
          Of the three calcified tissues – enamel, dentin and cementum – dentin is unique for a couple of reasons. Unlike enamel, which is formed largely in the womb, dentin continues to form throughout life. Under the right conditions, dentin production is stimulated in response to triggers like tooth decay and even chewing. Odontoblasts, cells very similar to the bone-building osteoblasts, line the surface of the pulp just beneath the dentin and continually produce new dentin. Dentin is also unique because it produces the Vitamin K2-dependent proteins osteocalcin and MGP (matrix gla protein).
          Tooth decay starts from outside the tooth. Cavity-causing bacteria produce acid that slowly eats through the enamel, then quickly eats through the more porous dentin. Traveling along the tiny dentin channels, bacteria quickly reach the pulp, which may become infected even before the tooth decay penetrates all the way through the dentin. Regular dental checkups and X-rays that spot cavities early will limit the progression of a cavity. Drilling out the decay and replacing the lost tooth matter with a filling effectively seals out bacteria and stops the cavity from growing. But that doesn’t prevent the process from starting all over again in another tooth, or even in another part of the same tooth. 
           There are a few different microorganisms involved in tooth decay, namely the Streptococcus species and certain strains of Lactobacillus acidophilus. If that last name sounds familiar, it’s because these bugs are considered to be probiotics – friendly, helpful bacteria – in other parts of the body. In the intestines, this species helps digest food and boost immunity. They are found in yogurt and probiotic supplements. Yes, we’ve been paying money for the bacteria that cause our teeth to rot. If those bacteria are so helpful elsewhere, why are they harmful in our mouth? What induces bacteria to attack teeth?
 According to the conventionally accepted understanding of tooth decay, cavities happen when foods containing sugars and starches, such as bread, soda pop, cookies, candy or even milk, are frequently left on the teeth. Mouth-dwelling bacteria thrive on these foods, producing acid that, over time, destroys tooth enamel, resulting in decay. Thus, eating high-carb foods and not brushing your teeth cause cavities because of this localized reaction. Good oral hygiene will reduce bacteria, while dietary changes reduce what they feed on. This is the chemicoparasitic theory of tooth decay.
          This narrow view of what causes cavities has us playing a losing game of catch-up with tooth decay – and it doesn’t leave room for the most effective and fundamental approaches to preventing cavities way before they start. Even with a low-sugar diet and regular brushing, flossing and professional cleaning, cavities happen. It is impossible to keep the mouth free of bacteria with dental hygiene. More to the point, Price found that “many primitive races have their teeth smeared with starchy food almost constantly and make no effort whatsoever to clean their teeth. In spite of this they have no decay.” Something else protected these people from both the bacteria and their cavity-causing activity: Vitamin K2.
          Price observed that people with active tooth decay had high levels of Lactobacillus acidophilus in their saliva, averaging around 323,000 microorganisms per milliliter. After treating his patients with Vitamin K2–rich butter oil, Price’s special concentrate of butter from grass-fed cows, the average bacteria content dropped to 15,000 bugs per milliliter of saliva, a reduction of 95 percent. In some cases, the bacteria disappeared completely. The almost complete elimination of bacteria was typical in “many hundred[s] of clinical cases in which dental caries [are] reduced apparently to zero, as indicated by both x-ray and instrumental examination.”
          The addition of dietary K2 changes the quality of saliva in another surprising way that fights tooth decay. The saliva of patients who have cavities tends to rob the teeth of minerals, according to another elegant experiment performed by the maverick dentist. When saliva from patients with active tooth decay was mixed with powdered bone or tooth chips, minerals moved from the tooth or bone into the saliva. The experiment was repeated with saliva from the same patients after they were treated with Vitamin K2. Then, minerals moved from the saliva into the bony tissue.
          After the pancreas, Vitamin K2 in humans exists in the highest concentration in the salivary glands. When rats are fed only K1, nearly all of the Vitamin K in their salivary glands exists as K2. Vitamin K2 accomplishes two things here. It reduces the number of cavity-causing bacteria, and it provides dentin with the menaquinone needed to activate MGP and osteocalcin. Once those proteins are activated by K2, they develop “claws” that grab onto calcium to deposit it where it’s needed. That mechanism alone could explain the tendency for minerals to be drawn into tooth tissue in the presence of Vitamin K2–rich saliva.
          Once Price recognized the value of Vitamins A, D, and K2 in treating tooth decay, he largely stopped drilling and filling teeth, except in cases where pain from a large, open cavity called for a temporary filling. Instead, he used a combination of high-vitamin cod liver oil (source of Vitamins A and D) and grass-fed butter oil (source of K2) as the foundation of his protocol for healing cavities. This protocol not only stopped the progression of tooth decay but completely reversed it by causing dentin to grow and remineralize, sealing what were once active cavities.
          Let me be clear that I am not advocating that you give up dental care and self-treat your family’s tooth decay with Price’s method, as described in these pages. A nutritional protocol for treating tooth decay should be overseen by a patient and informed dentist. I’m also not suggesting we all give up brushing and flossing. Even Price admitted that “of course everyone should clean his teeth, even the primitives, in the interest of and out of consideration of others.”

Excerpted from Vitamin K2 and the Calcium Paradox. Copyright 2012 by Kate Rhéaume-Bleue.
Excerpted with permission of the publisher John Wiley & Sons Canada, Ltd.