Could This ‘Humble’ Vitamin Hinder Future Cancers?

Vitamin K is sometimes referred to as the “forgotten” vitamin because it is often overshadowed by more well-known nutrients. However, vitamin K is not only essential for many bodily functions, it also offers an impressive array of benefits, not the least of which is lowering your risk of cancer.

These two new studies, the first of which connected vitamin K2 with a nearly 30 percent reduction in your risk of cancer mortality and a 14 percent lowered risk of cancer altogether, add to a growing arsenal of research highlighting vitamin K’s cancer-fighting potential.

Vitamin K: Your Ally in the Fight Against Cancer

Vitamin K is emerging as a powerful player in cancer prevention, and it may soon join the ranks of vitamin D for its health-boosting potential.

Most recently, the Mayo Clinic study noted above found a massive 45 percent lower risk of Non-Hodgkin lymphoma among people with the highest dietary intakes -- and the association held true even after accounting for other cancer influencers like smoking, alcohol use, obesity, and eating lots of foods that are high in antioxidants.

Vitamin K has also been found beneficial in the fight against other cancers, including liver, colon, stomach, nasopharynx, and oral cancers, and some studies have even suggested vitamin K may be used therapeutically in the treatment of patients with lung cancer, liver cancer, and leukemia.

One 2008 study by the European Prospective Investigation into Cancer and Nutrition (EPIC) also found that increased intake of vitamin K2 may reduce your risk of prostate cancer by 35 percent.

Interestingly, the potential benefits of vitamin K2 were most pronounced for advanced prostate cancer.

Are You Deficient in This Important Vitamin?

Many people in both the United States and the UK are not getting the currently recommended intakes, which are likely already too low to begin with. In fact, according to What We Eat In America NHANES 2001–2002, only one in four Americans are meeting the recommended levels of dietary vitamin K.

Further, the Institute of Medicine’s recommended daily intake of 120 micrograms for men and 90 for women are based on levels that will ensure adequate blood coagulation. But vitamin K is important for more than just blood clotting; it impacts the health of your bones, arteries and immune system as well.

Well, emerging research, including the “triage theory” from Joyce McCann, PhD and Bruce Ames, PhD, suggests that these other non-clotting functions that depend on vitamin K may need higher levels than are currently recommended.

Although the exact dosing is yet to be determined, one vitamin K expert, Dr. Cees Vermeer, recommends between 45 mcg and 185 mcg daily for adults. You must use caution on the higher doses if you take anticoagulants, but if you are generally healthy and not on these types of medications, I suggest at least 100 mcg of vitamin K2 daily.

Which Type of Vitamin K is Best?

There are three types of vitamin K. Vitamin K1, or phylloquinone, is found naturally in plants and vitamin K2, also called menaquinone, is made by the bacteria that line your gastrointestinal tract. Vitamin K3, or menadione, is a synthetic form that is manmade, and which I do not recommend.

You should strive to include both vitamin K1 and vitamin K2 in your diet.

K1 is found in dark green leafy vegetables, and makes up about 90 percent of the vitamin K in a typical Western diet. The following table lists some vegetable sources of K1 that you should consider eating frequently:

The best natural source of vitamin K2 is derived from an ancient Japanese food called Natto. Natto is made from fermented soybeans and significant amounts of vitamin K2 are produced during the fermentation process.

Although natto would be the highest source, other fermented foods like cheese are also loaded with it. If you find yourself not consuming enough fermented foods, you will certainly want to consider taking a supplement, especially if you have osteoporosis. Vitamin K2 is probably one of the least appreciated supplements to regain bone density.

It’s important to note that vitamin K is a fat-soluble vitamin. This means that in order for your body to absorb it effectively, you need to eat some fat along with it.

So please do make a point to increase your intake of vitamin-K rich foods, including fermented varieties. Given all the new research coming in, ensuring your body has adequate levels of vitamin K is too important to pass up.