Vitamin K is a fat-soluble vitamin that your body stores in your liver and fatty tissues. Vitamin K comes in three different forms, including K1 -- phylloquinone -- which comes from plants, K2 -- menaquinone -- which is made by your natural intestinal bacteria, and K3 -- menadione -- which is the synthetic, engineered form of the vitamin. Taking vitamin K supplements might help prevent broken bones, especially if you have osteoporosis, but you should consult your doctor before taking the supplement.
Function
Vitamin K's major function is to regulate your blood platelets' ability to form clots, says the University of Pittsburgh Medical Center. Specifically, vitamin K prevents excessive thinning of your blood and supports the clotting function. People who have a vitamin K deficiency may bleed uncontrollably -- or hemorrhage -- and have a suppressed ability to staunch the bleeding by forming blood clots, explains the University of Maryland Medical Center. Vitamin K also plays an important role in bone formation and density, notes the University of Michigan Health System.
Benefits
You might take a vitamin K supplement if you have a deficiency, typically due to a malabsorption syndrome like celiac disease, Crohn's disease or cystic fibrosis, says the University of Maryland Medical Center. People with gallbladder disease, liver disease or severe burns may also have a vitamin K deficiency.
Additionally, taking anticoagulant or antiplatelet medications like Coumadin or heparin and undergoing hemodialysis can lead to a vitamin K deficiency. Menopausal women who are at risk for or suffering from osteoporosis may benefit from vitamin K supplementation, due to the nutrient's role in strengthening your bones, notes the University of Pittsburgh Medical Center.
Other Uses
In addition to treating a deficiency or osteoporosis, vitamin K supplements are sometimes also recommended for women who suffer from menorrhagia or heavy menstruation, notes the University of Pittsburgh Medical Center. You might take vitamin K to ease nausea or to prevent hemorrhaging or excessive bleeding. Vitamin K is especially helpful for people who are at risk for hemorrhaging due to liver disease, chronic antibiotic use or malabsorption disorders, notes the University of Maryland Medical Center.
Dosage
The daily recommended intake of vitamin K is 90 micrograms for adult women and 120 micrograms for men, according to the University of Pittsburgh Medical Center. Infants up to 1 years of age should get 2 to 2 ½ micrograms of vitamin K each day, while children aged 1 to 8 years old should get 30 to 55 micrograms.
Adolescents 9 to 13 years old should get 60 micrograms of vitamin K daily, and teenagers 14 to 18 years old should get 75 micrograms. The therapeutic dosage of vitamin K for treating osteoporosis is much higher than the daily recommended intake, however. Taking 1mg of vitamin K each day reduced calcium loss through the urine in postmenopausal women, according to a 1989 study in the "Annals of Internal Medicine." Two other studies published in the "Journal of Bone Mineral Research" in 1992 and 2000 found that taking a whopping 45mg of vitamin K each day increased bone density and reduced bone loss in people with osteoporosis, says the University of Michigan Health System. Before taking a vitamin K supplement, ask your doctor about the dosage that's right for you.
Considerations
Keep in mind that you can get plenty of vitamin K from your diet, especially if you consume a lot of vegetables. For instance, a single serving of turnip greens or kale provides 10 times your daily requirement of vitamin K, says the University of Pittsburgh Medical Center. Most people don't require supplementation because you get vitamin K from these plant sources and the bacteria in your intestines manufactures vitamin K. Also, don't take vitamin K supplements if you're also taking blood-thinners like Coumadin, because the vitamin can render the drug ineffective, warns the University of Maryland Medical Center. If you're pregnant or breastfeeding, consult your physician before taking vitamin K supplements.
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