Vitamine K is veelzijdiger dan voorheen
gedacht. De vetoplosbare vitamine K kennen we vooral als essentiŽle voedingsstof voor de
bloedstolling, immers de synthese van verschillende bloedstollingsfactoren is afhankelijk
van vitamine K en een vitamine K-tekort kan leiden tot bloedingen. De letter K staat dan
ook voor het Duitse woord 'koagulation' ofwel bloedstolling. Dit is echter niet de enige
functie van vitamine K, die bestaat uit vitamine K1 (fyllochinon) en vitamine K2
(menachinon/MK). Onderzoekers hebben ontdekt dat het lichaam meer vitamine K-afhankelijke
eiwitten bezit waaronder osteocalcine, regulator van de botmineralisatie, en matrix Gla
proteÔne (MGP), remmer van kalkafzetting in zachte weefsels zoals kraakbeen en
bloedvaten. Er is toenemend bewijs dat een subklinisch vitamine K-tekort een serieuze
risicofactor is voor botontkalking, gewrichtsslijtage en verkalking van de slagaderwand,
en dat het verbeteren van de vitamine K-status (vooral met vitamine K2) helpt om deze
degeneratieve processen tegen te gaan.(1-3)
Vitamine K en botmassa /
Het traditionele Japanse ontbijtgerecht
natto (gefermenteerde sojabonen) blijkt het risico op osteoporose (de aandoening die
botbreuken veroorzaakt bij meer dan 80.000 mensen in Nederland) te verminderen. Natto
bevat hoge concentraties vitamine. Van vitamine K is inmiddels bekend dat het een
belangrijke rol speelt bij het behoud van gezonde botten. Uit een placebogecontroleerde
studie van onderzoekers aan de Universiteit van Maastricht , bleek dat Vitamine K2
helpt bij het verbeteren van de hoeveelheid botmineraal en de breedte van het heupbot.
Daarom zou deze relatief onbekende vitamine kunnen helpen bij het voorkomen van aan
osteoporose gerelateerd botverlies bij vrouwen na de menopauze.
Vitamine K maakt botten sterk en
houd de vaatwand soepel
Vitamine K is betrokken bij de
bloedstolling en de synthese van bepaalde eiwitten in de lever, het bot, de tanden het
kraakbeen en de arteriŽle vaatwand. In het lichaam wordt vitamine K1 vooral in de lever
geconcentreerd. In de overige organen, zoals bloedvaten en beenderen, is vitamine K2 de
belangrijkste vorm. Vooral vitamine K2 (MK-7) ondersteunt de gezondheid van bloedvaten en
beenderen. Ter ondersteuning van de botstofwisseling is ook vitamine D 3 belangrijk.
Study gives vitamin K
Increased intake of vitamin K1, and to a
lesser extend vitamin D, could protect against inflammation, and positively effect chronic
disease risk, suggests a new observational study.
Vitamin K Status Among Children
With Cystic Fibrosis and Its Relationship to Bone Mineral Density and Bone Turnover
Vitamin K1 deficiency is common among
children with CF, and routine supplements should be considered. Through its role in the
carboxylation of OC, vitamin K deficiency may be associated with an uncoupling of the
balance between bone resorption and bone formation. A cause-effect relationship between
vitamin K deficiency and low bone mass has not been proved.
Vitamin K May Help Clear Arteries
Animals given high levels of vitamin K showed a 37 percent reduction in calcium buildup in
their arteries, a new study finds. Arterial calcification is an independent risk factor
for cardiovascular disease, researchers noted. The Dutch study, by researchers at
Maastricht University, is the first in animals to show that arterial calcification and
resulting decreased arterial elasticity can be reversed by consuming high levels of
vitamin K. The findings support the results of a Rotterdam population-based study
published in 2004. This research into the benefits of high vitamin K intake may prove
especially important for people taking blood thinning medications, such as warfarin, which
are known to cause rapid calcification in the arteries. Many patients taking blood
thinners aren't aware of this risk, the researchers said. Vitamin K is found in many kinds
of foods, including soybean, olive and canola oils, and dark green vegetables such as
broccoli, kale, spinach and Brussels sprouts. Vitamin K is also available in supplements.
The study was funded by Maastricht University and is published in the April 1 issue of the
The Risk of Childhood Cancer after
Neonatal Exposure to Vitamin K
Two recent studies have found that infants
who received intramuscular vitamin K were at twice the expected risk for cancer during
childhood. Since nearly all newborns in the United States receive this drug, the public
health implications of this association, if confirmed, would be substantial.
Bacteria that normally colonize the large
intestine synthesize menaquinones (vitamin K2), which are an active form of
vitamin K. Until recently it was thought that up to 50% of the human vitamin K requirement
might be met by bacterial synthesis. However, research indicates that the contribution of
bacterial synthesis is much less than previously thought, although the exact contribution
Vitamin K status is associated with
childhood bone mineral content.
van Summeren MJ, van Coeverden SC,
Schurgers LJ, Braam LA, Noirt F, Uiterwaal CS, Kuis W, Vermeer C. Department of Paediatric
Immunology, University Medical Centre Utrecht, PO Box 85090, Utrecht, The Netherlands.
In adult bone, vitamin K contributes to
bone health, probably through its role as co-factor in the carboxylation of osteocalcin.
In children, the significance of vitamin K in bone-mass acquisition is less well known.
The objective of this longitudinal study was to determine whether biochemical indicators
of vitamin K status are related to (gains in) bone mineral content (BMC) and markers of
bone metabolism in peripubertal children. In 307 healthy children (mean age 11.2 years),
BMC of the total body, lumbar spine and femoral neck was determined at baseline and 2
years later. Vitamin K status (ratio of undercarboxylated (ucOC) to carboxylated (cOC)
fractions of osteocalcin; UCR) was also measured at both time points. Markers of bone
metabolism, sex steroids, vitamin D status and growth hormones were measured at baseline
only. Large variations in the levels of the UCR were found at both time-points, indicating
a substantial interindividual difference in vitamin K status. Improvement of vitamin K
status over 2 years (n 281 children) was associated with a marked increase in total body
BMC (r - 49.1, P < 0.001). The UCR was associated with pubertal stage, markers of bone
metabolism, sex hormones and vitamin D status. A better vitamin K status was associated
with more pronounced increase in bone mass in healthy peripubertal children. In order to
determine the significance of these findings for childhood bone health, additional
paediatric studies are needed.
Br J Nutr. 2008 Feb 18;:1-7
Update on Tufts vitamin K research
Boston In a recent article in
Current Opinion in Clinical Nutrition and Metabolic Care, Sarah Booth, PhD, lab director
of the Vitamin K Laboratory at the Jean Mayer USDA Human Nutrition Research Center on
Aging at Tufts University (USDA HNRCA), reviewed studies regarding vitamin K status among
the elderly. Although older adults seem to consume more vitamin K than younger adults,
many seniors are still not meeting the recommended intake of vitamin K.
"Research has shown poor vitamin K
intake may be associated with conditions such as bone fractures, bone loss, hardening of
the arteries, and osteoarthritis," says Booth, who is also a professor at the
Friedman School of Nutrition Science and Policy at Tufts.
Although it may be important for the
elderly to increase dietary vitamin K, Booth notes that it is also essential for
researchers to examine factors other than diet that may affect vitamin K status in the
body. "One promising area of research is the interrelationship between estrogen and
vitamin K," says Booth, "as studies indicate that low estrogen levels in
menopause may change the way vitamin K is metabolized. More research is also needed to
determine vitamin K status of elderly men, as well as to determine what populations, if
any, might benefit from vitamin K supplements."
In a study published in Nutrition,
Metabolism & Cardiovascular Diseases, Booth and colleagues examined dietary patterns
of more than 40,000 men to determine if phylloquinone, the form of vitamin K found in
plant sources like leafy green vegetables, could serve as a marker for reduced risk of
developing cardiovascular disease.
Booth and colleagues, including
corresponding author Arja Erkkila, PhD, of both the USDA HNRCA and the University of
Kuopio in Finland, determined that high phylloquinone intake did not appear to be an
independent risk factor for cardiovascular disease. However, men consuming high amounts of
phylloquinone generally had better dietary habits, such as eating more fruits and
vegetables and less saturated fat. Men consuming high amounts of phylloquinone were also
less likely to smoke and more likely to exercise or take dietary supplements.
The association between high phylloquinone
intake and a healthy diet and lifestyle led Booth and colleagues to conclude that
phylloquinone intake could indeed play an important role in cardiovascular research
studies. "...In large population groups, phylloquinone may provide a more robust
assessment of overall cardiovascular risk status than assessing multiple individual diet
and lifestyle habits," write the authors.
Osteoporosis: Vitamin D and Vitamin
Vitamin D helps enhance calcium absorption
in the body and helps with bone formation. When taken along with calcium, Vitamin D plays
a critical role in maintaining bone density.
Stunning new research shows that
vitamin K may be one of the most extraordinary anti-aging vitamins ever discovered. It has
unique powers no other vitamin possesses
Vitamin D has dominated discussion on bone
because it is a hormone that acts swiftly and dramatically. But the slower-acting vitamin
K is just as important. And although it doesn't act as quickly on bone as vitamin D, new
research indicates that vitamin K may actually be more of a hormone than currently
Prophylactic vitamin K for vitamin
K deficiency bleeding in neonates.
Vitamin K deficiency can cause bleeding in
an infant in the first weeks of life. This is known as Hemorrhagic Disease of the Newborn
(HDN). HDN is divided into three categories: early, classic and late HDN. Early HDN occurs
within 24 hours post partum and falls outside the scope of this review. Classic HDN occurs
on days one to seven; common bleeding sites are gastrointestinal, cutaneous, nasal and
from a circumcision. Late HDN occurs from week 2-12; the most common bleeding sites are
intracranial, cutaneous, and gastrointestinal.
Vitamin K and vitamin D status:
associations with inflammatory markers in the Framingham Offspring Study.
Shea MK, Booth SL, Massaro JM, Jacques PF,
D'Agostino RB Sr, Dawson-Hughes B, Ordovas JM, O'Donnell CJ, Kathiresan S, Keaney JF Jr,
Vasan RS, Benjamin EJ. Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts
University, Boston, MA 02111, USA.
In vitro data suggest protective roles for
vitamins K and D in inflammation. To examine associations between vitamins K and D and
inflammation in vivo, the authors used multiple linear regression analyses, adjusted for
age, sex, body mass index, triglyceride concentrations, use of aspirin, use of
lipid-lowering medication, season, menopausal status, and hormone replacement therapy.
Participants were from the Framingham Offspring Study (1997-2001; n = 1,381; mean age = 59
years; 52% women). Vitamin K status, measured by plasma phylloquinone concentration and
phylloquinone intake, was inversely associated with circulating inflammatory markers as a
group and with several individual inflammatory biomarkers (p < 0.01). Percentage of
undercarboxylated osteocalcin, a functional measure of vitamin K status, was not
associated with overall inflammation but was associated with C-reactive protein (p <
0.01). Although plasma 25-hydroxyvitamin D was inversely associated with urinary
isoprostane concentration, an indicator of oxidative stress (p < 0.01), overall
associations between vitamin D status and inflammation were inconsistent. The observation
that high vitamin K status was associated with lower concentrations of inflammatory
markers suggests that a possible protective role for vitamin K in inflammation merits
PMID: 18006902 Am J Epidemiol. 2008 Feb
Association of hip fracture
incidence and intake of calcium, magnesium, vitamin D, and vitamin K.
Yaegashi Y, Onoda T, Tanno K, Kuribayashi
T, Sakata K, Orimo H. Department of Hygiene and Preventive Medicine, School of Medicine,
Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan,
Objective To analyze the association
between hip fracture incidence in 12 regional blocks within Japan and dietary intake of
four key nutrients: calcium, magnesium, vitamin D, and vitamin K. Design An ecological
study. Methods Using data from the 2002 national survey on the incidence of hip fracture
and the National Nutritional Survey of Japan, a standardized incidence ratio of hip
fracture was calculated, and the association between the standardized incidence ratio and
each nutritional intake was assessed for each region using Pearson's correlation
coefficient and partial correlation analysis. Results There were significant correlations
between the standardized incidence ratio by region and magnesium, vitamin D, and vitamin K
in both men and women, and calcium in women. The strongest inverse correlations were found
in vitamin K in both men and women (r = -0.844, P = 0.001, and r = -0.834, P = 0.001,
respectively). After adjusting for calcium, magnesium, and vitamin D, the partial
correlation between the standardized incidence ratio by regional block and vitamin K was
strongest in both men and women (partial correlation coefficient, pcc = -0.673, P = 0.04;
pcc = -0.575, P = 0.106, respectively). Conclusions The significant correlation between
hip fracture incidence and vitamin K intake, and also regional variations in food
patterns, suggest that increasing intake of vegetables and legumes might lead to a
decrease in hip fracture incidence in the future. Further, this study suggests that a
review of the dietary reference value of vitamin K from the perspective of osteoporosis
would be useful.
Eur J Epidemiol. 2008;23(3):219-25. Epub
2008 Jan 24
Vitamin K may reverse artery
hardening, suggests study
A high-dose vitamin K supplement reduced
calcium precipitates associated with hardening of the arteries by 37 per cent in rats,
scientists from The Netherlands have reported.
Vitamin K: Another Reason To Eat
What is the best source of vitamin K?
Vegetables provide the lion's share of this vitamin in the diet. But nutritionists have
assumed that people absorb more from oil or oil-based supplements than from vegetables. To
find out, Booth led a study with colleagues at Yale University School of Medicine to
compare the absorption and useknown as bioavailabilityof vitamin K from
broccoli and from oil fortified with the vitamin. For 5 days each, volunteers consumed a
helping of broccoli or fortified oil along with a base diet. This increased their
phylloquinone intake to around 400 Ķg/dayfive to six times the RDA. "What's
really exciting," Booth says, "is to look at the functional markers for vitamin
K status. There were no differences between vitamin K from broccoli and vitamin K from oil
overall. That's good because green leafy vegetables contain so many other nutrients."
U-M study suggests vitamin K
deficiency as an osteoporosis risk factor
A new study by Jane Lukacs of the
University of Michigan School of Nursing suggests that the impairment of vitamin K
function could compromise bone health and contribute to the development of osteoporosis.
The study found that one of the early effects of declining estrogen is the impairment of
vitamin K function in bone even before any bone loss that could be attributed to menopause
can be measured. "Our study suggests that the generally accepted level of vitamin K
in healthy women is inadequate to maintain bone health just at the onset of
menopause," Lukacs said.
Vitamin K is essential for making a bone
protein called osteocalcin fully functional. This protein is part of the bone structure
when it is "carboxylated" (a chemical modification of the protein that changes
its shape making it easy to bind to calcium) in the presence of sufficient vitamin K. With
adequate vitamin K, this protein can bind to calcium in the bone environmentsort of
like glue, Lukacs said. The study involved volunteer human subjects of whom 80 percent
were white with the remainder of African-American, Hispanic and Asian heritage. All were
healthy middle-aged women or young adult women. The study included blood tests, interviews
to determine dietary habits and calculation of the body mass index and measurement of bone
mineral density of the lumbar spine and the non-dominant hip. If right handed, left hip.
While vitamin K comes from green leafy
vegetables, green vegetables and vegetable oils, most individuals don't consume amounts on
a consistent basis that are sufficient to promote bone health. Few multivitamins contain
vitamin K, and those that do have minimal amounts of vitamin K. Anyone considering vitamin
K supplements should consult with their medical adviser first; people on blood thinners
should not be taking vitamin K. So, what's a woman to do? For now, Lukacs suggests getting
back to basics. "In early menopause, increase your intake of dark green vegetables
and vegetable oils on a daily basis," she said. "In adolescence and early
adulthood, the incorporation of weight-bearing exercise is crucial because we also
observed lower bone density in the hip of premenopausal women in their late 40's well
before the onset of menopause.
"Many factors contribute to the
development of osteoporosis and fracture risk," Lukacs said. "Part of our effort
in this study was to examine vitamin K as a novel nutritional factor that may play a role
in bone health in a group of women well characterized for their vitamin nutriture,
reproductive status and age, something that is rarely attempted in descriptive
studies." She said it will be important to explore whether vitamin K supplementation
in the early postmenopause will offer an additional intervention for women concerned about
their future risk of fracture.