The Disadvantages Of Vitamin K

Vitamin K is a fat-soluble vitamin that is essential for the ability of blood in the body to clot. While vitamin K is an essential nutrient, it can also cause complications in patients who take medication for blood-clotting disorders, affecting both the effectiveness of their medications and increasing their risk of fatal clots. Vitamin K is found in a large variety of foods, with many of these foods providing many times more vitamin K than is a recommended daily allowance. Because of this, patients on anti-coagulation therapy need to be aware of which foods contain vitamin K, how much is contained and the potential risk to their health if they consume large amounts of vitamin K-rich foods.

Foods With High Amounts of Vitamin K

Vitamin K is found in variety of foods, making vitamin K deficiency not a common problem in adults. The disadvantage of these foods and the intake of vitamin K comes if you are in a high-risk category for blood clots or cardiovascular disease. The vitamin K found in these foods can interact with medications and increase your body's ability to clot. According to the National Institutes of Health Office of Dietary Supplements, the recommended daily value of vitamin K for adults is 80 mcg. However, many foods containing vitamin K contain much more than that. For example, a 1/2-cup serving of kale contains 660 percent more than the daily recommended values. Other foods containing more than 200 percent of the recommended values include spinach, turnip greens, collards, Swiss chard and mustard greens.

Medication Interactions

Anti-coagulant medications, such as warfarin, are used to prevent blood clots from forming. According to the National Institutes of Health, warfarin is prescribed to patients with irregular heartbeat, artificial heart valves or a previous history of a heart attack or a stroke. They are also prescribed to patients to treat or prevent venous thrombosis, or swelling and blood clots in the veins. Because vitamin K helps make your blood clot, consuming vitamin K in large doses can affect the effectiveness of warfarin and the treatment it is trying to provide. The National Institutes of Health advises patients on warfarin to talk with their physician regarding their diet and to avoid leafy green vegetables with high amounts of vitamin K.

Side Effects of Vitamin K Supplementation

Vitamin K supplements are given to patients with bleeding disorders to increase the blood's clotting ability. According to the Mayo Clinic, vitamin K comes in both tablet and capsule form and its brand-name is Mephyton. Taking this vitamin K supplement can cause various side effects, including flushing of the face, unusual taste, decreased appetite, decreased movement or activity, difficulty breathing, irritability, muscle stiffness, paleness and yellowing of the eyes and skin.

Considerations

When it comes to vitamin K, consult with your physician before adding supplements. If you are at risk of blood clots or cardiovascular risk, learn which foods are high in vitamin K and how they can affect your medications and their intended treatment.