Vitamin K is a fat-soluble vitamin, essential for the human body to function properly. Vitamin K can be stored in and absorbed from fatty tissue in the body, and it is found in many types of foods and supplements. Although vitamin K deficiency is rare, it can cause serious problems, especially for people with certain health conditions. Obtaining the recommended daily amount of vitamin K is important.
Benefits
Vitamin K plays a key role in the ability of blood to clot properly. According to MedlinePlus, some studies indicate vitamin K may also help maintain strong bones in elderly individuals. Adequate amounts of vitamin K are essential for newborns to help reduce potentially dangerous problems with bleeding and hemorrhaging in the brain.
Recommendations
Dietary reference intakes for vitamin K vary by gender and age. The Food and Nutrition Board has established adequate intakes, or AIs, for vitamin K, which are believed to meet the needs of healthy individuals in each population group. The AIs for vitamin K include 120 mcg for adult males and 90 mcg for adult females including pregnant and breastfeeding women. Vitamin K AIs are lower for children and vary by age. The Merck Manual of Medical Information recommends all newborns be given a vitamin K injection to help prevent a deficiency.
Sources
Food sources of vitamin K include mainly leafy green vegetables and some fruits. According to the University of Florida, the following foods contain significant amounts of vitamin K: iceberg lettuce, cabbage, turnip greens, spinach, kale, broccoli and soybean oil. Vitamin K is also made by the healthy bacteria that live in the human gut. Vitamin K may or may not be present in multivitamin supplements and can also be administered by injection, as is the case with newborns.
Deficiencies
Vitamin K deficiencies can occur because of lack of vitamin K in the diet, the presence of certain diseases that reduce vitamin K absorption, or the effects of certain medications you may be taking. A vitamin K deficiency can result in increased bruising, excessive bleeding, decreased blood clotting or hemorrhaging.
Concerns
Consuming high amounts of vitamin K from foods or supplements can be dangerous for people who are at risk for developing dangerous blood clots and are taking certain medications. Large amounts of vitamin K can sometimes interfere with certain blood-thinning drugs, such as warfarin -- also known as Coumadin.
References
- MedlinePlus; Vitamin K; Linda Vorvick, MD; March 2009
- Food and Nutrition Board: Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Vitamins
- The Merck Manual of Medical Information Second Home Edition; Vitamin K; Larry E. Johnson, MD, PhD; August 2007
- University of Florida IFAS Extension; Facts About Vitamin K; R. Elaine Turner, Wendy J. Dahl
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