I’ve arrived at the third and final article in my series on vitamin K, the lesser-known vitamin. Here we look at evidence about its use against liver cancer, as well as a conclusion about getting enough of it, and where to find it.
First let’s look at liver cancer for which, recently, vitamin K has shown promising results. Several new studies attest to this intriguing and important possibility.
2004: In 40 women with virus-related liver cirrhosis, 45 milligrams (mg) a day of vitamin K was tested. The results: cancer was found in two of 21 people given the vitamin versus nine in 19 not taking the vitamin.
2006: In 61 patients who had surgery to remove the tumor in their liver, 45 mg a day reduced the recurrence rate of cancer after the procedure.
2006: In 42 patients with advanced liver cancer, 50 mg a day of vitamin K3 was used, followed by another 20 mg injected into the muscles (twice a day for two weeks). The results: the vitamin improved survival in 17% of patients.
2007: In 60 patients had surgery or radiation on liver cancer, 45 mg a day was used. The results: vitamin K reduced the recurrence rate, but did not improve survival.
Next, let’s look into whether you’re getting enough vitamin K. The Food and Nutrition Board of the Institute of Medicine established what is known as the adequate intake (AI) for vitamin K, among other nutrients. Men should get 120 mcg (micrograms) of vitamin K per day and women should get 90 mcg per day. In general, multivitamins contain 10 to 25 mcg of vitamin K.
Dr. Higdon at The Linus Pauling Institute (Portland, OR), makes the following recommendations:
— To lower hip fracture risk, get 250 mcg of vitamin K per day. This amount can be achieved by eating more than a half-cup of chopped broccoli or a large salad of mixed greens every day.
— So that the proteins work properly, especially in people over 65, take a multivitamin/mineral supplement and eat at least one cup of dark green leafy vegetables daily.
Vitamin K1, the major food source of vitamin K, is found in vegetable oils such as soybean and canola oils, as well as in green leafy vegetables such as cabbage, spinach, kale, broccoli and lettuce. Cauliflower, soybeans, cow milk, and Brussels sprouts are also good sources of this vitamin. On the other hand, vitamin K2 is mainly found in cheese, meat and fermented products. Our own intestinal bacteria can also produce vitamin K2, but this amount contributes only minimally to your overall vitamin K levels.