Vitamin K is a fat soluble vitamin that is broken down and absorbed by fat throughout your body. Since it is readily available from several foods in your diet, and because your body can make it, deficiency is rare. Vitamin K plays several key roles in basic functions, but it is most commonly know for its ability to help blood clot.
Types of Vitamin K
There are two forms of naturally occurring vitamin K: phylloquinone, or K-1 from plants and menaquinone, or K-2 from bacteria. Your body produces small amounts of K-2 in the intestine. While both K-1 and K-2 are not harmful at high doses, it is possible to have an allergy to these types of vitamin K, explains the Linus Pauling Institute. Vitamin K-3 is a synthetic form of the vitamin, found in fortified foods and dietary supplements. K-3 can be toxic in high amounts, causing damage to cell membranes.
Function of Vitamin K
Vitamin K is essential for the activation of enzymes that speed up processing of a certain amino acid, known as glutamic acid. This process results in a conversion of glutamic acid to gamma-carboxyglutamic acid, a critical step for calcium binding. Vitamin K and its ability to bind calcium is required for activating seven different proteins that help with coagulation, leading to blood clotting. The liver synthesizes vitamin K-dependent coagulation factors. Having severe liver disease may result in diminished function of vitamin K, causing uncontrolled bleeding known as a hemorrhage.
Vitamin K Dosage
As adults, women need 90 mcg of vitamin K each day while men need as much as 120 mcg, reports Medline Plus. If you are pregnant or breastfeeding, your daily requirement of vitamin K does not change. There is not an established tolerable upper limit for toxicity of vitamin K, as there is for many other nutrients. While vitamin K is stored, your body only stores small amounts and you can become deficient if you don't consume foods rich in vitamin K every day.
Food Sources
Leafy green veggies are loaded with vitamin K. Just 1 cup of chopped raw kale provides nearly 550 mcg of vitamin K. Other beneficial veggies include 1 cup of steamed broccoli, which contains 220 mcg, 1 cup of raw spinach, has 145 mcg. The same amount of shredded green leaf lettuce contains more than 60 mcg. Fats are another way to get your vitamin K. A 1 tbsp. serving of olive oil has 8 mcg, soybean oil provides 25 mcg and mayonnaise contains nearly 4 mcg per tablespoon.
