Vitamin K is a fat-soluble vitamin that is often called the blood coagulation or anti-hemorrhagic vitamin. Vitamin K is found in a variety of plant and animal foods, including vegetable oils, green, leafy vegetables, most meats and dairy products. Vitamin K is essential for the formation of compounds involved in the blood-clotting process. Although vitamin K is an essential nutrient, high levels of vitamin K intake may result in side effects. Consult with your physician before taking a nutritional supplement containing vitamin K.
Toxicity
Despite being a fat-soluble vitamin, there is no known toxicity of vitamin K. However, synthetic forms of vitamin K, called vitamin K-3, may be toxic in high doses. According to Oregon State University, high amounts of vitamin K-3 may interfere with the function of your body's natural antioxidants, resulting in oxidative damage to cell membranes, liver damage, jaundice and hemolytic anemia. The high toxicity of synthetic vitamin K has prompted the Food and Drug Administration to ban the use of vitamin K-3 in nutritional supplements.
Allergic Reaction
An allergic reaction to vitamin K supplements is rare but possible. An allergic reaction to vitamin K causes an increase in histamine levels, which can have potentially serious side effects. Symptoms of a vitamin K allergy include nausea, vomiting, diarrhea, upset stomach, swelling of your face and throat, difficulty breathing and heart palpitations. Seek medical attention immediately if you begin to develop any of the symptoms associated with a possible allergy to vitamin K.
Stomach Distress
High amounts of vitamin K supplementation may cause gastrointestinal side effects, although this may be related to other compounds found in the capsule of the tablet or pill containing vitamin K and not vitamin K itself. The most common gastrointestinal side effects related to vitamin K supplementation are nausea, upset stomach, persistent stomach cramps, indigestion, diarrhea, vomiting and headache. These side effects are usually mild, and the likelihood of experiencing stomach distress with vitamin K decreases if you take the supplement with food and water.
Medication Interactions
Vitamin K supplementation may interfere with drugs used to prevent blood clots, such as warfarin. The long-term use of broad spectrum antibiotics may decrease the metabolism of vitamin K by the presence of intestinal bacteria. Other drugs, such as cephalosporins and salicylates, may decrease vitamin K synthesis. Consult with your physician to ensure vitamin K will not interfere with the function or absorption of any medications you are taking.
References
- "Nutrition for Health, Fitness, and Sport"; Melvin H. Williams; 2002
- OSU; Vitamin K; Jane Higdon; 2004
- Cancer.org; Vitamin K; 2010
Member Comments