Vitamin K2 linked to better heart health

[Guest guest]

K2 in the diet associated with lower incidence of calcification of the

arteries.

Link:

http://www.nutraingredients-usa.com/Publications/Food-Beverage-Nutrition/NutraIn\

gredients/Research/Vitamin-K2-linked-to-better-heart-health/?c=NMXU1kQxIQqXW5vui\

x6fUA%3D%3D

Full text:

Vitamin K2 linked to better heart health

By ls

10-Sep-2008 -

Increased intakes of vitamin K2 from dietary sources may reduce the

build up of calcium in arteries that leads to hardening of the blood

vessels, says a new study.

A higher intake of K2, but not K1, was associated with a 20 per cent

reduction in calcification of the arteries, according to findings

published in the journal Atherosclerosis.

" This study shows that high intake of menaquinone [K2], but probably

not phylloquinone [K1], is associated with reduced coronary

calcification. Adequate intakes of menaquinone could therefore be

important for the prevention of cardiovascular disease, " wrote lead

author Joline Beulens from the University Medical Center Utrecht.

The study, which examined the dietary habits and cardiovascular health

of 564 post-menopausal women, adds to a growing body of science

linking the vitamin to improved heart health.

However, as the researchers state, results have been inconsistent,

potentially due to " different effects of phylloquinone and menaquinone

on coronary calcification " , they said.

Atherosclerosis, known as hardening or furring of the arteries is a

key risk factor for cardiovascular disease, the cause of over 50 per

cent of deaths in Europe and the US.

Study details

Beulens and co-workers assessed the diets of the 564 women (average

age 67, average BMI 26.7 kg per sq. m) using a 77-item food frequency

questionnaire (FFQ). A technique called multi-detector computed

tomography (MDCT) was used to assess levels of arterial calcification.

The researchers report that the average intake of vitamin K1 was 217

micrograms per day, while vitamin K2 intakes averaged 31.6 micrograms

per day for the whole study population.

Furthermore, 82 per cent of the K1 came from vegetables, while K2 came

predominantly from cheese (54 per cent), milk products (22 per cent),

and meat (15 per cent).

Based on the MDCT exam 62 per cent of the women had calcification of

the arteries, said the researchers. When the intakes of K1 and K2 were

divided into four groups from the lowest to highest, no association

was found between K1 intakes and calcification. However, high

consumption of K2 (about 45 micrograms per day) was associated with 20

per cent decreased coronary calcification, compared with low

consumption of K2 (about 18micrograms per day).

Explaining the differences between vitamin K forms

The metabolism of menaquinone and phylloquinone was cited as the

probable reason as to why the different forms of vitamin K showed

different results with respect to calcification.

" Phylloquinone is predominantly transported with the

triacylglycerol-rich fraction, which is mainly cleared by the liver.

Phylloquinone is therefore very effectively cleared from circulation

by the liver to function as a cofactor for proteins in blood

coagulation, " wrote the researchers.

" Menaquinones, on the other hand, are found in both

triacylglycerol-rich lipoprotein and low-density lipoprotein, which

are equally transported to extrahepatic tissues, " they said.

" Menaquinone could therefore more effectively influence MGP and

coronary calcification. "

MGP (matrix Gla protein) is a regulator of calcium crystal formation

in the circulatory system. MGP is a vitamin K-dependent protein -

meaning vitamin K is required to activate this important protein.

Comment

Commenting on the study, vitamin K researcher Leon J Schurgers from

VitaK at the Maastricht University in the Netherlands said: " This

study confirms once again that natural Vitamin K2, also called the

menaquinones, is clearly linked to the prevention of cardiovascular

disease. "

" While all K vitamins are important, it seems that especially the

natural vitamin K2 intake is essential to cardiovascular health, "

added Schurgers, who was not involved in the Utrecht study.

The vitamin K family

Phylloquinone (vitamin K1) is found in green leafy vegetables such as

lettuce, broccoli and spinach, and makes up about 90 per cent of the

vitamin K in a typical Western diet.

Menaquinones (MK-n: with the n determined by the number of prenyl side

chains) make up about 10 per cent of Western vitamin K consumption and

can be obtained from different dietary sources. MK-4 can be found in

animal meat, MK-7, MK-8, and MK-9 are found in fermented food products

like cheese, and natto is a rich source of MK-7.

MK-4 is distinct from other MKs because it is not a major constituent

of the spectrum of MKs produced by gut microflora, but can be derived

from K1 in vivo.

A synthetic form of vitamin K, known as K3, does exist but is not

recommended for human consumption.

Source: Atherosclerosis

Published online ahead of print, doi:10.1016/j.atherosclerosis.2008.07.010

" High dietary menaquinone intake is associated with reduced coronary

calcification "

Authors: J.W.J. Beulens, M.L. Bots, F. Atsma, M.-L.E.L. Bartelink, M.

Prokop, J. M. Geleijnse, J.C.M. Witteman, D.E. Grobbee, Y.T. van der

Schouw