If you are considering which vitamins might be beneficial to your liver’s health, make sure you know about the pros and cons of supplementing with Vitamin K.
Predominantly involving Vitamins A, B, C and E, most of us think of vitamins as morning pills that help keep people healthy. While that preconception is mostly true, the generalization that all vitamins are good for you is far from accurate. Because the liver must process the vitamins we consume, the healthfulness of dietary supplements is especially important and complex when evaluating which vitamins are beneficial to those with liver concerns. When it comes to the lesser-known Vitamin K, seemingly conflicting information may have people with chronic liver disease needing guidance.
About Vitamin K
Vitamin K is necessary for the synthesis of the proteins that help control bleeding (clotting factors), and thus for the normal clotting of blood. The “K” is derived from the German word “koagulation.”
Found in several different forms, Vitamin K is a fat-soluble vitamin that refers to a group of compounds called naphthoquinones. There are three different types of Vitamin K:
· Vitamin K1 – Found naturally in leafy green vegetables such as broccoli and spinach, vegetable oils, cereals and some meats and cheeses, this natural form of Vitamin K is gathered through dietary consumption. Also known as phytonadione, Vitamin K1 is commercially manufactured for medicinal use under several brand names, including Phylloquinone®, Phytonadione®, AquaMEPHYTON®, Mephyton® and Konakion®.
· Vitamin K2 – Referred to as menaquinones, Vitamin K2 compounds are made by bacteria in the intestines. While some countries use this form for supplementation, only small amounts of Vitamin K2 can be absorbed.
· Vitamin K3 – Vitamin K3 is not a naturally occurring form of Vitamin K. Instead, it is a water-soluble, synthetic preparation that is manufactured in laboratories. Also called menadione, synthetic Vitamin K3 was originally used to treat Vitamin K deficiency in newborns. However, menadione has been proven to cause severe damage to the liver. Because of its liver toxicity, menadione has been banned by the FDA as an over-the-counter supplement.
Vitamin K Deficiency
While relatively rare in adults, those with liver disease are at increased risk of Vitamin K deficiency. This is because the liver synthesizes bile acids and secretes them into the small intestine where they play a critical role in absorption of lipids. As a fat-soluble vitamin, Vitamin K requires proper lipid absorption to be absorbed. Thus, liver disease that results in decreased bile salt synthesis can lead to impaired Vitamin K absorption and deficiency. In addition, a majority of the blood’s clotting factors are made almost exclusively in the liver, so liver disease can cause defects in blood clotting by several other mechanisms.
Newborns are prone to Vitamin K deficiency for two reasons:
1. Only small amounts of Vitamin K cross the placenta.
2. During the first few days after birth, infants’ intestines do not contain bacteria to produce Vitamin K.
This deficiency can cause hemorrhaging where a baby has an increased tendency to bleed. A Vitamin K injection is usually given to newborns to protect them from this problem.
Vitamin K for Liver Disease
A Vitamin K deficiency might be suspected if abnormal bleeding occurs in people with conditions that put them at risk – such as liver disease. Doctors typically diagnose a Vitamin K deficiency by performing blood tests to measure how well blood clots, and by finding out how much Vitamin K a person consumes. While taking Vitamin K orally or via injections usually corrects this problem, those with a Vitamin K deficiency and severe liver damage may also need blood transfusions to replenish clotting factors. This is because a damaged liver may be unable to synthesize clotting factors even after Vitamin K injections are given.
A study published in the July 21, 2004 issue of The Journal of the American Medical Association strongly links Vitamin K to a lowered risk of liver cancer in those most at risk for the disease. The discovery was made accidentally during research on bone loss. Although the mechanism explaining why Vitamin K prevents or inhibits liver cancer cell growth remains unclear, the researchers involved in this study concluded that there is a possible role for Vitamin K in the prevention of liver cancer in those with advanced liver disease.
In the study described above, Vitamin K2 was isolated as a potential cancer fighter, but not all Vitamin K’s are the same. Since the synthetic Vitamin K can cause damage to the liver, menadione is never advised for anyone with liver concerns.
Vitamin K is essential for healthy blood coagulation, a process that prevents a simple abrasion from becoming deadly. For newborns or those diagnosed with a Vitamin K deficiency, injections or supplementation might be appropriate. In addition, people with liver disease could possibly benefit from this vitamin, but more research is needed to confirm why – and ascertain its safety. While eating an abundance of foods rich in Vitamin K appears to be perfectly healthy, Vitamin K3 poses a real danger to anyone who takes it – especially someone with liver disease.
http://findarticles.com/p/articles/mi_m0FKA/is_10_66/ai_n6198002/, Vitamin K cuts liver cancer risk, Retrieved September, 14, 2010, PRIMEDIA Intertec/Gale Group/CBS Interactive Inc., 2010.
http://jama.ama-assn.org/cgi/content/abstract/292/3/358?view=short&fp=358&vol=292&lookupType=volpage, Role of Vitamin K2 in the Development of Hepatocellular Carcinoma in Women With Viral Cirrhosis of the Liver, Daiki Habu, MD, PhD, et al, Retrieved September 16, 2010, The Journal of the American Medical Association, July 2004.
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http://www.ncbi.nlm.nih.gov/pubmed/18374204, Hepatocellular carcinoma and vitamin K, Mizuta T, et al, Retrieved September 16, 2010, Vitamins and Hormones, 2008.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-vitamink.html, Vitamin K, Retrieved September 16, 2010, US National Library of Medicine, 2010.
http://www.vivo.colostate.edu/hbooks/pathphys/misc_topics/vitamink.html, Vitamin K, R. Bowen, Retrieved September 16, 2010, Colorado State University, 2010.
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