Vitamin K
Recommended Intake
Vitamin K Deficiency
Vitamin K Toxicity
Major Food Sources
Tips for Increasing Your Vitamin K Intake

Vitamin K is a fat-soluble vitamin. Fat-soluble vitamins are stored in the body in the liver and fatty tissues. Unlike the other fat-soluble vitamins, the body actually stores very little vitamin K, making regular dietary intake important. Bacteria in the large intestines help out by synthesizing a range of vitamin K forms called menaquinones. Vitamin K is also produced by plants (phylloquinone) and is primarily found in green vegetables (collards, spinach, salad green, broccoli), Brussels sprouts, cabbage, and plant oils. The manmade vitamin K found in supplements is called menadione.

Vitamin K's functions include:

• playing an essential role in the blood clotting process by making the proteins that stop bleeding
• helping your body make other proteins essential for blood, bones, and kidneys

Recommended Intake:

Vitamin K Deficiency
If you don't get enough vitamin K, your blood will not clot normally. Among healthy people, a deficiency is rare. Symptoms of vitamin K deficiency include:

• easy bruising and bleeding (nosebleeds, bleeding gums, blood in the urine, blood in the stool, or extremely heavy menstrual bleeding)
• bleeding in the skull (intracranial hemorrhage) in infants

The following groups of people may be at risk for a vitamin K deficiency and may require a supplement:

• People taking anticoagulant, or blood-thinning, drugs. It is generally recommended that people taking these drugs try to consume the adequate intake for vitamin K (90 to 120 micrograms) from food sources, but not more. Supplementing vitamin K can cause drug interactions in people taking anticoagulant or blood-thinning drugs. Vitamin K deficiency is uncommon in healthy adults. If you are taking an anticoagulant, talk to your doctor about your vitamin K intake before changing your eating habits. Drastic changes in the amount of vitamin K you eat can affect how these drugs work.
• People taking vitamin E or aspirin. Vitamin E and aspirin are also blood thinners and can interfere with vitamin K.
• People taking antibiotics. In addition to killing harmful bacteria, antibiotics also destroy the healthful bacteria that live in the intestines and produce vitamin K.
• Exclusively breast-fed newborn babies who do not receive a vitamin K injection. These babies may be deficient because human milk can be low in vitamin K and newborns do not yet have the bacteria that will make vitamin K in their intestines. For these reasons, and because a deficiency of this vitamin can be life-threatening, the American Academy of Pediatrics recommends that all newborns receive an injection of phylloquinone, the plant-based vitamin K. This is the standard of care in many hospitals.

Vitamin K Toxicity
As a fat-soluble vitamin, vitamin K is stored in the body and not excreted in the urine like most water-soluble vitamins. Though no symptoms have been observed among people consuming excess amounts, moderation is still recommended. People taking blood-thinning drugs, or anticoagulants, may need to limit their intake of vitamin K-rich foods because too much vitamin K can make those drugs less effective in thinning the blood. In some infants given injection, the synthetic forms of vitamin K (menadiones), have caused liver toxicity, jaundice, and rupture of the blood cells. No tolerable intake level (UL) has been established for vitamin K.

Major Food Sources

Tips for Increasing Your Vitamin K Intake
To help increase your intake of vitamin K

• Slice an avocado. Add a little balsamic vinegar and pepper, and scoop out for a snack. Or, mash the avocado and mix with chopped tomatoes and red onions for a refreshing salsa.
• Pack a kiwi and spoon in your lunch for an afternoon snack. The insides of the kiwi can be scooped out and eaten from this natural and easy container.
• Steam ½ cup broccoli or Brussels sprouts, add lemon juice (1 tablespoon), pre-chopped garlic (1 teaspoon), and Dijon mustard (1 tablespoon). Or add broccoli to your favorite lasagna or hot dish.
• Mix two (10-ounce) packages of frozen chopped spinach, thawed, well drained, 1 8-ounce package of softened low-fat cream cheese, ¼ cup milk, and 1 teaspoon lemon pepper until well blended. Spoon into a 1-quart casserole dish and sprinkle with 1/3 cup crushed crackers or seasoned croutons. Bake at 350 degrees until thoroughly heated (about 25 to 30 minutes).