Vitamin K is a fat-soluble vitamin that helps your blood clot properly and aids in depositing calcium in your bones. There are two main forms of vitamin K -- K1 and K2, phylloquinone and menaquinone, respectively. Phylloquinone is the form of vitamin K found primarily in plants. Various menaquinone derivatives are found in animal proteins. Bacteria in your large intestine produce MK-7, which is an active form of menaquinone. Some plant foods such as fermented soybean products are rich in menaquinone, as well as kefir and fermented yogurts and cheeses.
Requirements
Adults have the highest requirement of vitamin K -- men require 120 mcg per day, and women require 90 mcg per day. Infants up to the age of 12 months require up to 3 mcg of vitamin K per day. Newborns are given injections soon after birth because newborns aren't able to produce any vitamin K for blood-clotting purposes. Children 1 to 3 years of age need 30 mcg of vitamin K per day; children 4 to 8 need 55 mcg per day; and older children and teenagers require 60 to 75 mcg per day of vitamin K, according to the Linus Pauling Institute at Oregon State University.
Deficiency
Vitamin K deficiency results in poor blood clotting, easy bruising and possibly osteoporosis. Phylloquinone, or vitamin K1, is more readily available for blood-clotting purposes in the body. Vitamin MK-7 activates bone proteins to increase calcium deposits in your bone. When vitamin K1 levels are low, you bruise more easily and have longer bleeding times because your blood can't form blood clots as effectively. Vitamin K2 deficiency decreases calcium deposits in your bone and increases calcium building up in your blood.
Diet
Phylloquinone is the predominant vitamin K source in the diet, especially the western diet. Green leafy vegetables, vegetable oils, soybeans and soybean oils are rich sources of vitamin K. According to the Linus Pauling Institute, hydrogenated oils may increase vitamin K absorption; yet, you are advised to avoid hydrogenated fats because the consumption of trans fats increases your risk of heart disease.
Bone Health
MK-7, an advanced, fat-soluble form of vitamin K, is active in preventing bone loss and promoting bone formation, Dr. Alan Petersen says in his article "Vitamin K -- Much More Than a Coagulation Vitamin" in the June 2008 issue of "The Journal of Lancaster General Hospital." The proteins of your bones readily accept MK-7 to support calcium deposition in your bones, and because of this high affinity for MK-7, calcium isn't deposited in your organs and other soft tissues. Low intakes of MK-7 increase your risk of developing soft, brittle bones, which can lead to osteoporosis.
Artery Calcification
Low levels of MK-7 are related to calcium deposition in your artery walls. Research done by Johanna Geleijnse and colleagues in the Rotterdam Study showed that vitamin MK-7 activates a special bone protein -- matrix GLa-protein -- to increase bone density. When MK-7 levels are low, the matrix GLa-protein levels aren't active for bone formation. This leaves calcium free to be deposited in soft tissues and your arteries rather than your bones. The conclusion Geleijnse and colleagues reached was that heart disease developed in people with low MK-7 levels.
References
- Linus Pauling Institute: Vitamin K
- "The Journal of Lancaster General Hospital"; Vitamin K---Much More Than a Coagulation Vitamin; Dr. Alan Peterson; 2008
- "Journal of Nutrition"; Dietary Intake of Menaquinone Is Associated With a Reduced Risk of Coronary Heart Disease: The Rotterdam Study"; Johanna M. Geleijnse et al.; 2004
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