It is safe to say that a large majority of the population has heard of vitamin K, just as they have heard of every other vitamin that health experts advise people to take. However, the facts about vitamin K2 are not as widely known. For instance, are you aware that vitamin K1 and vitamin K2 serve two completely different purposes in the body? Most people don’t realize this distinction because vitamin K2 was only discovered in 1929, relatively late compared to the discovery of other well-known vitamins (1). Now, there is more evidence than ever that vitamin K2 is just as necessary for our bodies and our health.
Heart disease is the leading cause of death in the United States. One of the early warning signs that you may have heart disease is the presence of calcium deposits in the aorta. Vitamin K1 does not prevent this from happening, but vitamin K2 may play a role on this front. There are also many other important health benefits of vitamin K2 that vitamin K1 does not have. Confused? Well, first you need to understand why there are two different kinds of vitamin K, and the main differences between the two.
K1 versus K2: The Differences
There are a few different forms of vitamin K, which gets its name from the German word “koagulation.” Coagulation is the process in which blood clots (2). The two forms of vitamin K that occur naturally are K1 (phylloquinone) and K2 (menaquinone). So, what’s the difference between the two? (3) First of all, vitamin K1 is synthesized by plants, and vitamin K2 is synthesized by bacteria. More importantly, they each serve different purposes in the human body. Vitamin K1 is used by the liver to trigger normal blood clotting proteins to do their job. Vitamin K2, however, deals with calcium.
If your shoppers are avid users of calcium supplements, or if they make a conscious effort to include a lot of calcium in your diet, they probably think that their bones will automatically reap the benefits. However, calcium cannot fully benefit the bones without vitamin K2. It is responsible for depositing calcium where it is needed, such as in the bones and teeth, and prevents calcium from accumulating in soft tissue or in the arteries (4). Without adequate amounts of vitamin K2, some calcium can end up in places it does not belong, and not enough will go to the bones, causing them to become brittle. It is extremely important that calcium be deposited in the proper places, because correct deposition can prevent certain diseases.
Neither form of vitamin K is necessarily better or worse than the other, because they serve different purposes. However, it is a fact that many people have trouble properly absorbing vitamin K1. If shoppers are concerned about bone and heart health, vitamin K2 is the way to go. Menaquinone, or MK7, is its natural form, but it can also be made synthetically (5).
Helper to Your Heart
Vitamin K2 has been found to prevent coronary heart disease. In order to understand how it accomplishes this feat, we must first look at one of the major causes of heart attack. The risk of a heart attack is increased when there is calcification of the aortic valve and/or arteries. That is where vitamin K2 steps in. It inhibits calcification of the aortic valve and arteries (6). Vitamin K2 prevents calcification by activating the carboxylation of the Matrix Gla Protein (MGP), which is the strongest inhibitor of calcification in the arteries that is presently known (7). The Journal of Nutrition published a landmark study, entitled “The Rotterdam Study,”which linked vitamin K2 to heart disease prevention. The participants, 7,983 men and women ages 55 and over, lived in Rotterdam, Netherlands. Over a period of three years, from 1990 to 1993, researchers at the Erasmus Medical Center in Rotterdam collected data on the participants’ current health, medication use, medical history, lifestyle and risk indicators for chronic disease. The information was collected during extensive interviews conducted at the participants’ homes. Then, each person underwent a clinical examination at the study center, where their diets were also assessed. The participants had to check off which foods and beverages they consumed more than once a month over the course of the previous year. That way, those performing the study could assess the intake of vitamin K in the participants’ diets (8). Over the next seven years, from 1993 to 2000, follow-up data were collected from 98% of the participants. The researchers found that those who had consumed more vitamin K2 had less calcification in their aortas. The same connection was not significant enough to be made with vitamin K1. The study concluded that intake of vitamin K2 prevents against coronary heart disease in older men and women (8). Evidence also shows that vitamin K2 could actually reverse arterial calcification (5). While this is excellent news, more good news is on the way: vitamin K2 also protects against osteoporosis!
Building Brawny Bones
Bone health is incredibly important, especially as we age. Ensuring that you get enough vitamin K2 each day can help you to keep your bones strong, and reduce your risk of fractures, breaks and osteoporosis (3). Women who have undergone menopause are especially at risk, which is why it is crucial that young and older women get enough calcium, vitamin D, magnesium and vitamin K2. Vitamin K2 works by activating osteocalcin, which is a protein that binds calcium to the intercellular makeup of the bones. The binding of calcium causes the bone to become stronger and less brittle (7). Vitamin K2 is necessary for the proper distribution of calcium, so getting enough calcium from diet or supplement is not enough by itself.
A Japanese study found that vitamin K2 lessened the occurrence of spinal fractures by 52% in 120 patients with osteoporosis. The doses used in the study were 45 mg/day, but scientists are still debating the DRI of vitamin K2. There is an extensive range between the amount some researchers recommend daily and the amount that others recommend, so shoppers should contact their doctors before deciding on a dosage (1).
Wave Goodbye to Wrinkles
Cardiovascular benefits and bone health benefits? This vitamin seems almost too good to be true…but the good news only gets better! A study published in the Longevity Medicine Review shows that vitamin K2 may prevent wrinkles and varicose veins, which are sure signs of aging that many people are obsessed with preventing (9). The article notes that there is evidence that people whose bodies do not properly metabolize vitamin K have severe wrinkles in their skin at an earlier age.
Further support of vitamin K2’s aging benefits is the fact that it activates carboxylation of MGP, which inhibits calcium from depositing in elastin fibers (10). Similarly, MGP stops the mineralization of muscle cells in the walls of veins, which is the cause of vericose veins. A study was conducted by the University of Nantes in France, in which the healthy veins of 36 males ages 30 to 83 were compared with the vericose veins of 50 males ages 40 to 81. High levels of uncarboxylated MGP were found solely in the vericose veins. Vitamin K2 was then added to cultures of the muscle cells from the vericose veins, and MGP was activated and mineralization decreased (10).
The food source with the highest amount of vitamin K2 is Natto, a Japanese food made from fermented soybeans (11). Other foods include egg yolk and green vegetables such as broccoli, kale, spinach, Brussels sprouts and asparagus. Vitamin K2 has also been found in carrots, beets and fermented foods such as sauerkraut. However, the amount of vitamin K2 in these foods is extremely low, and it is hard to get enough solely from diet. In fact, vitamin K1 occurs naturally more often than vitamin K2 (9). That is why some people choose to take vitamin K2 supplements to ensure that they are getting the required amount. Remember, if shoppers are thinking of taking vitamin K2 in supplement form, tell them to consult their doctor to discuss dosage (the daily recommended intake for vitamin K is 100 mcg). Those who are on blood thinning medication should take precaution, as vitamin K2 may work negatively in the presence of anticoagulation drugs. In addition, those who have suffered from stroke, heart attack or who are prone to blood clotting should definitely check with their doctors before taking any vitamin K2 supplements. WF
1. W. Davis, “Protecting Bone and Arterial Health With Vitamin K2,” Life Extension, March 2008, http://www.lef.org/magazine/mag2008/mar2008Protecting-BoneAnd-Arterial-Health-WithVitamin-K2_01.htm, accessed Feb. 7, 2011.
2. J. Higdon, “Vitamin K,” Linus Pauling Institute, May 2004, http://lpi.oregonstate.edu/infocenter/vitamins/vitaminK/, accessed Feb. 7, 2011.
3. “Vitamin K,” www.vitamins-supplements.org/vitamin-K.php, accessed Feb. 4, 2011.
4. “Vitamin K2, the Missing Nutrient,” May 6, 2008, http://thehealthyskeptic.org/vitamin-K2-the-missing-nutrient, accessed Feb. 2, 2011.
5. R.A. Passwater, “Vitamin K2 Puts Calcium in Bones and Removes Calcium From Arteries, Part 1,” WholeFoods Magazine, 32 (2), 70–73 (2009).
6. “The Function of Vitamin K2,” www.fitday.com/fitness-articles/nutrition/vitamins-minerals/the-function-of-vitamin-K2.html, accessed Feb. 7, 2011.
7. “Vitamin K2: The Menaquinones,” www.vitaminK2.org, accessed Jan. 28, 2011.
8. J.M. Geleijnse, et al., “Dietary Intake of Menaquinone Is Associated with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study,” J. Nutr. 134 (11) 3100–3105.
9. GiGi, “Vitamin K- Who Knew?” Anti-Aging Nutrition News, April 25, 2008. http://antiagingnutritionnews.com/blog/138/vitamin-k-who-knew, accessed Feb. 9, 2011.
10. Longevity Medicine Review, “Vitamin K,”www.lmreview.com/articles/view/vitamin-k/, accessed Feb. 9, 2011.
11. “Vitamin K2 Could Prevent Cardiovascular Disease,” Total Health [serial online]. February 2008; 30 (6):15. Available from: Academic Search Complete, Ipswich, MA. accessed Jan. 28, 2011.
Published in WholeFoods Magazine, April 2011