On Your Radar: Vitamin K

March 05, 2013

The power of nutrition never ceases to impress and here’s more reason to include more veggies in your diet!

We all know that consuming a variety of different foods, in their most natural, least processed form is best for our health, and can do wonders in terms of disease prevention - but nonetheless, it never ceases to impress, when new studies emerge revealing the ‘power’ of vitamins to fight infection, prevent chronic disease or even improve memory. A study in the American Journal of Clinical Nutrition looked into the association between vitamin K intake and the overall risk of developing cancer. Those with the highest vitamin K intake from food were less likely to experience cancers.

Vitamin K is necessary for a variety of functions in your body, including normal blood clotting, antioxidant activity, and optimal bone health. There are two natural forms of vitamin K: vitamin K1, from plants and K2 from animal sources. Great sources of K1 include, parsley, kale, spinach, Swiss chard, collard greens, celery, asparagus, brussel sprouts, soy beans, and avocado among others. Plant sources (K1) are key in building and maintaining healthy bones, as K1 activates a protein that anchors calcium to the bone. The plant sources mentioned are also great sources of other bone-building nutrients like calcium, boron and magnesium. Vitamin K2, derived from animal sources including, egg yolk, butter, certain cheeses, meat and the fermented soy product natto, is also extremely important in bone health, blood clotting, and protecting cells from oxidative damage.

The study, conducted by Dr. Linseisin and colleagues at the German Cancer Research Center in Heidelberg, found that those who consumed the highest amounts of vitamin K2 (the upper quartile) were 28 percent less likely to develop or die from cancer, specifically lung cancer, than those in the lowest quartile. This association remained true after factors like age, exercise habits, weight, smoking, consumption of other nutrients were taken into account.

In previous studies, vitamin K has been shown to inhibit cancer cell growth and promote the process by which abnormal cells kill themselves off- apoptosis. Linseisin and colleagues report that whether vitamin K intake itself is responsible for lower cancer risks is unclear due to several study limitations. Limitations include, methods of reporting dietary intake and the fact that other components of vitamin K rich foods are related to cancer risk. However the findings of this study lay the foundation for future studies.

The current USDA recommended daily intake for vitamin K, in all forms, is 120 micrograms (mcg) for men and 90 mcg for women.

The study mentioned, “Dietary vitamin K intake in relation to cancer incidence and mortality: results from the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition”, can be found in the American Journal of Clinical Nutrition Note in the AJCN study, men in the highest vitamin K intake group consumed 92 mcg a day or more; their female counterparts consumed at least 84 mcg per day.

Always consult your physician before making any dietary changes.