Turnips, beets, onions, rutabaga and pumpkin are some vegetables that are low in vitamin K. Each of these vegetables contains 2 or fewer micrograms of vitamin K per 1 cup serving.
People who are taking the blood thinner Coumadin should keep their vitamin K intake at a consistently low level. Vegetables that are low in vitamin K include root vegetables such as butternut squash, spaghetti squash, potatoes and sweet potatoes. Butternut and spaghetti squash each contain roughly 2 micrograms of vitamin K per 1 cup serving. One cup of potatoes contains roughly 3 micrograms of vitamin K, while 1 cup of sweet potatoes contains roughly 7 micrograms.
Other vegetables that are low in vitamin K include bamboo shoots, tomatoes, iceberg lettuce and artichokes. Some vegetables lose vitamin K when they are cooked. For example, cooked tomatoes contain about 7 micrograms of vitamin K per cup, while raw tomatoes have double the amount of vitamin K at 14 micrograms per cup. Iceberg lettuce and artichokes each contain just over 17 micrograms of vitamin K per cup.
Portabella, white and cooked Shiitake mushrooms are all free from vitamin K. Vitamin K is found in the highest concentrations in dark leafy greens such as spinach, Swiss chard and kale. People on low vitamin K diets should avoid these types of greens.