|
Other common
name(s): the clotting vitamin, vitamin K1, vitamin K2,
vitamin K3
Scientific/medical
name(s): phylloquinone, phytonadione, menaquinone,
menadione
Description
Vitamin K is an essential nutrient that is needed by the liver
in order to form proteins that promote blood clotting and prevent
abnormal bleeding. There are 3 forms of vitamin K: K1, K2, and K3.
Vitamin K1 (phylloquinone or phytonadione) is a natural nutrient found
in green leafy vegetables, such as lettuce, cabbage, collard greens,
broccoli, and turnip greens. Some oils, such as soybean oil and canola
oil, contain vitamin K. It is also found in beans, olives, cereals,
dairy products, some fruits, liver, and pork. Cooking does not remove
the vitamin. Vitamin K2 (menaquinone) is a natural product of bacteria
that reside in the lower intestinal tract. Vitamin K3 (menadione) is a
potent synthetic (manmade) form of vitamin K.
Overview
Vitamin K is necessary for normal blood clotting and may be
necessary for other activities. The human body obtains vitamin K from
certain foods and bacteria that normally live in the intestines.
Available scientific evidence does not support the use of vitamin K
supplements for cancer treatment or prevention. However, a small
clinical trial found that a compound similar to vitamin K2 seemed to
reduce the recurrence of liver cancer after surgery.
How is it promoted for use?
Vitamin K is known primarily as a blood-clotting nutrient.
However, some alternative medical practitioners claim that vitamin K3
is also an anticancer agent. Others claim that high doses of vitamin K3
and vitamin C supplements can inhibit tumor growth when taken together.
Available scientific evidence does not support these claims.
Vitamin K is also promoted as an ingredient in some cosmetic
or herbal creams to lighten redness caused by broken blood vessels and
to treat skin irritation (burns and sunburns) and scarring. They are
often called "clarifying" creams and are usually recommended to be
applied to the skin every day for several weeks.
What does it involve?
Healthy adults who eat plenty of leafy green vegetables
generally get all the vitamin K they need from natural sources. The
Food and Nutrition Board considers 90 micrograms per day for women and
120 micrograms per day for men to be an adequate intake (1 milligram is
equal to 1,000 micrograms). Foods usually provide the body with about
half of the normal supply of the vitamin, while intestinal bacteria
produce the rest.
Only those who have symptoms of a vitamin K deficiency may
need to take supplements. The signs of a deficiency include abnormal or
excessive bleeding, such as frequent nosebleeds, abnormally bleeding
gums, heavy menstruation, or blood in the urine or stool. People with
these symptoms should see a doctor because these signs may also signal
other, more serious, problems. A deficiency may result from extended
treatment with antibiotics, which can kill the bacteria that produce
vitamin K; liver damage; or intestinal disorders such as celiac
disease, cystic fibrosis, or removal of part of the intestine. Chronic
malnutrition, including alcoholism, can also cause vitamin K
deficiency.
Newborns lack the bacteria in their intestines to produce
vitamin K and may be at risk of serious bleeding. Newborns are usually
given vitamin K supplements, either by injection or by mouth, while in
the hospital. Babies who receive the supplements in the hospital do not
need more supplements after they leave.
Phytonadione or phylloquinone (vitamin K1) and menaquinone
(vitamin K2) supplements are available in tablet and capsule form from
health food stores and on the Internet. The U.S. Food and Drug
Administration (FDA) does not allow menadione (vitamin K3) to be sold
as a dietary supplement for humans, although it is allowed in some
feeds for farm animals.
What is the history behind it?
In 1935, a Danish scientist discovered that vitamin K was
essential to blood clotting and named it for the Danish word for
clotting, Koagulations. Since then, laboratory and animal studies have
been conducted to see whether vitamin K plays a role in preventing the
development or spread of cancer, but there is no convincing evidence
available to suggest that it does. However, in the 1990s, researchers
began to worry about a possible link between childhood cancers,
especially leukemia, and injections of vitamin K supplements in
newborns. Further study has found no link between cancer and vitamin K
injections. The American Academy of Pediatrics' latest recommendations
advise that all newborns should receive the injection to prevent
serious bleeding.
What is the evidence?
There is overwhelming scientific evidence that vitamin K is
necessary for blood clotting. The intestinal bacteria that produce
vitamin K are not present at birth. To avoid a deficiency of this
vitamin that can lead to serious bleeding, most pediatricians recommend
that an injection of vitamin K be given to newborns.
Some studies have suggested a link between low vitamin K
intake or low blood levels of this vitamin and increased risk for some
types of cancer. A large European epidemiologic study published in 2008
found higher risk of prostate cancer in men with low intake of some
forms of vitamin K. A small clinical trial from Japan suggested that
vitamin K lowers the risk of developing liver cancer among women with
cirrhosis.
An animal study done in 1998 found that a manmade form of
vitamin K known as compound 5 might slow the growth of cancer cells.
Since then, several additional studies have suggested that some forms
of vitamin K might be active against cancer cells in laboratory dishes
or mice. Laboratory studies are pinpointing how it works and what kinds
of cancer it might help. However, clinical trials on humans will be
needed to find out whether vitamin K compounds play a role in cancer
treatment.
There have been some studies examining whether menadione
(vitamin K3) can help overcome resistance to certain types of
chemotherapy drugs. Results in laboratory animals and cell cultures are
mixed, but there is no evidence available of significant effects in
humans yet. A small Phase I clinical trial in California recently
tested different doses of intravenous vitamin K3 in people with
advanced cancer. The patients showed no improvement. In that study,
several patients also had allergic reactions, especially at higher
doses.
A 2006 clinical trial suggested that menatetrenone, a compound
very similar to vitamin K2, may be able to reduce recurrence of liver
cancer after surgery. This was a small pilot study, and more research
is needed to be sure of this effect.
Some small, early studies also suggest that vitamin K might
have a role in keeping bones strong, especially in older people.
Further research is needed to confirm this and, if confirmed, to
determine the best way to use the vitamin.
One small human study looked at vitamin K cream to see whether
it helped bruises to disappear faster after laser treatments.
Researchers had people apply vitamin K cream twice a day to one side of
their body and a dummy cream, or placebo, to the other. Bruises seemed
to go away more quickly on the side of the body on which vitamin K
cream was used. More studies still need to be done to find out whether
this holds true and what concentration of cream is most effective.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike companies that produce
drugs (which must provide the FDA with results of detailed testing
showing their product is safe and effective before the drug is approved
for sale), the companies that make supplements do not have to show
evidence of safety or health benefits to the FDA before selling their
products. Supplement products without any reliable scientific evidence
of health benefits may still be sold as long as the companies selling
them do not claim the supplements can prevent, treat, or cure any
specific disease. Some such products may not contain the amount of the
herb or substance that is written on the label, and some may include
other substances (contaminants). Though the FDA has written new rules
to improve the quality of manufacturing processes for dietary
supplements and the accurate listing of supplement ingredients, these
rules do not take full effect until 2010. And, the new rules do not
address the safety of supplement ingredients or their effects on health
when proper manufacturing techniques are used.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
Natural vitamin K is considered safe as a normal part of a
daily diet. Supplements of the vitamin are not usually needed unless
recommended by a physician.
Injectable formulas of vitamin K (vitamin K3) can cause
allergic reactions and some toxic effects. During clinical trials of
vitamin K3, some patients experienced flushing of the face, numbness in
their arms and legs, chest pain, and shortness of breath. Immediate
severe allergies can cause shock and even death. Sometimes a milder
reaction happens in the form of an itchy bump that comes up where the
injection was given. The bump can take over a month to go away and can
sometimes cause scarring. Injectable vitamin K can also cause red blood
cells to be destroyed in some people.
Rarely, allergic rashes can develop after using vitamin K
creams on the skin.
Those who are on the blood-thinning medication warfarin
(Coumadin) should know that vitamin K can make warfarin less effective.
Talk with your health care provider before taking vitamin K supplements
or changing the amount of vitamin K you take in through your diet.
Pregnant women who are on anti-seizure medicines should get
vitamin K supplements for 2 to 4 weeks before giving birth because of
increased risk of bleeding in the newborn. Otherwise, the safety of
vitamin K supplements during pregnancy is not known, although the
vitamin K in foods is thought to be safe. Relying on this type of
treatment alone and avoiding or delaying conventional medical care for
cancer may have serious health consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
American Academy of Pediatrics Committee on Fetus and Newborn.
Controversies concerning vitamin K and the newborn. Pediatrics.
2003;112:191-192.
Ansell P, Bull D, Roman E. Childhood leukaemia and
intramuscular vitamin K: findings from a case-control study. BMJ.
1996;313:204-205.ita
Center for Food Safety and Applied Nutrition. Food additive
status list. US Food and Drug Administration Web site.
http://www.cfsan.fda.gov/~acrobat/opa-appa.pdf. Accessed June 6, 2008.
Food and Nutrition Board. Dietary reference intakes: vitamins.
Institute of Medicine Web site.
http://www.iom.edu/Object.File/Master/7/296/webtablevitamins.pdf.
Accessed June 6, 2008.
Ge L, Wang Z, Wang M, Kar S, Carr BI. Involvement of c-Myc in
growth inhibition of Hep 3B human hepatoma cells by a vitamin K analog.
J Hepatol. 2004;41:823-829.
Habu D, Shiomi S, Tamori A, Takeda T, Tanaka T, Kubo S,
Nishiguchi S. Role of vitamin K2 in the development of hepatocellular
carcinoma in women with viral cirrhosis of the liver. JAMA.
2004;292:358–361.
Kaneda M, Zhang D, Bhattacharjee R, Nakahama K, Arii S, Morita
I. Vitamin K2 suppresses malignancy of HuH7 hepatoma cells via
inhibition of connexin 43. Cancer
Lett. 2008;263:53-60.
Lim D, Morgan RJ Jr, Akman S, Margolin K, Carr BI, Leong L,
Odujinrin O, Doroshow JH. Phase I trial of menadiol diphosphate
(vitamin K3) in advanced malignancy.
Invest New Drugs. 2005;23:235-239.
McKinney PA, Juszczak E, Findlay E, Smith K. Case-control
study of childhood leukaemia and cancer in Scotland: findings for
neonatal intramuscular vitamin K. BMJ.
1998;316:173-177.
Mizuta T, Ozaki I, Eguchi Y, Yasutake T, Kawazoe S, Fujimoto
K, Yamamoto K. The effect of menatetrenone, a vitamin K2 analog, on
disease recurrence and survival in patients with hepatocellular
carcinoma after curative treatment: a pilot study. Cancer.
2006;106:867-872.
Nimptsch K, Rohrmann S, Linseisen J. Dietary intake of vitamin
K and risk of prostate cancer in the Heidelberg cohort of the European
Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg). Am J Clin Nutr.
2008;87:985-992.
Ni R, Nishikawa Y, Carr BI. Cell growth inhibition by a novel
vitamin K is associated with induction of protein tyrosine
phosphorylation. J Biol
Chem. 1998;273:9906-9911.
Parker L, Cole M, Craft AW, Hey EN. Neonatal vitamin K
administration and childhood cancer in the north of England:
retrospective case-control study. BMJ.
1998;316:189-193.
Passmore SJ, Draper G, Brownbill P, Kroll M. Case-control
studies of relation between childhood cancer and neonatal vitamin K
administration. BMJ.
1998;316:178-184.
Passmore SJ, Draper G, Brownbill P, Kroll M. Ecological
studies of relation between hospital policies on neonatal vitamin K
administration and subsequent occurrence of childhood cancer. BMJ.
1998;316:184-189.
Russell RM. Vitamin and trace mineral deficiency and excess.
In Braunwald E, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL,
eds. Harrison's
Principles of Internal Medicine. 15th ed. Washington DC:
McGraw-Hill; 2001:467.
Serra-Baldrich E, Dalmau J, Pla C, Muntañola AA.
Contact dermatitis due to clarifying cream. Contact Dermatitis.
2005;53:174-175.
Shah NS, Lazarus MC, Budgodel R, Hsia SL, He J, Duncan R,
Baumann L. The effects of topical vitamin K on bruising after laser
treatment. J Am Acad
Dermatol. 2002;47:241-244.
Tetef M, Margolin K, Ahn C, Akman S, Chow W, Coluzzi P, Leong
L, Morgan RJ Jr, Raschko J, Shibata S, et al. Mitomycin C and menadione
for the treatment of advanced gastrointestinal cancers: a phase II
trial. J Cancer Res
Clin Oncol. 1995;121:103-106.
US Department of Agriculture. Vitamin K: another reason to eat
your greens. Agricultural Research Service Web site.
http://www.ars.usda.gov/is/AR/archive/jan00/green0100.htm. Updated
August 13, 2004. Accessed June 6, 2008.
Vitamin K deficiency. Merck Manual of Diagnosis and Therapy
Online Edition. Merck Web site.
http://www.merck.com/mmpe/sec01/ch002/ch002a.html#tb002_1. Accessed
June 23, 2008.
Vitamin K. Medline Plus Web site.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-vitamink.html.
Updated March 1, 2008. Accessed June 6, 2008.
von Kries R. Oral versus intramuscular phytomenadione: safety
and efficacy compared. Drug
Saf. 1999;21:1-6.
von Kries R, Hachmeister A, Göbel U. Can 3 oral 2 mg
doses of vitamin K effectively prevent late vitamin K deficiency
bleeding? Eur J Pediatr.
1999;158 Suppl 3:S183-S186.
Xu CJ, Zhang Y, Wang J, Zhang TM. Menadione reduced
doxorubicin resistance in Ehrlich ascites carcinoma cells in vitro. Zhongguo Yao Li Xue Bao.
1998;19:273-276.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
|
