Dietary sources for vitamin K

The highest concentrations of vitamin K (in the
form of phylloquinone) are found in green leafy vegetables,
e.g. cabbage, broccoli, Brussels sprouts and
spinach. Such vegetables are the top contributors to
vitamin K intake in the American diet. Other types
of vegetables (roots, bulbs and tubers), cereal grains
and their milled products, fruits and fruit juices are
poor sources of vitamin K. Animal products (meat,
fi sh, milk products and eggs) contain low concentrations
of phylloquinone, but appreciable amounts of
menaquinones are present in liver.
Some vegetable oils, including canola (rapeseed),
soybean and olive oils, are rich sources of phylloquinone,
whereas peanut and corn (maize) are not. Soybean
oil is the most commonly consumed vegetable
oil in the American diet. The addition of phylloquinone-
rich vegetable oils in the processing and cooking
of foods that are otherwise poor sources of vitamin K
makes them potentially important dietary sources of
the vitamin. This is particularly evident, for example,
when chicken, eggs and potatoes are fried in certain
vegetable oils. Those margarines, mayonnaises and
regular-calorie salad dressings that are derived from
phylloquinone-rich vegetable oils are second to green
leafy vegetables in their phylloquinone content. The
addition of these fats and oils to mixed dishes and
desserts has an important impact on the amount of
vitamin K in the American diet.
Various menaquinones have been found in fermented
foods (Sakano et al., 1988), salmon, shellfi
sh, beef, pork, chicken, egg yolk, cheese and butter
(Hirauchi et al., 1989a) but the amounts may not
be nutritionally signifi cant in some of these foods.
Livers of ruminant species (e.g. cow) contain signifi
cant concentrations (10–20 μg per 100 g) of some
menaquinones (Hirauchi et al., 1989b), while cheese
contains signifi cant quantities of MK-8 (5–10 μg per
100 g) and MK-9 (10–20 μg per 100 g) (Shearer et al.,
1996).