Vitamin K is essential for clotting, bone health, and preventing calcification of your arteries. Most Americans don’t meet even the minimal intake guidelines for Vitamin K.
Vitamin K was first identified to be essential for normal clotting, (vitamin K as in German for
Over time, we have discovered that vitamin K is also essential for bone and artery health. Without adequate vitamin K, bones lose calcium, increasing your risk for osteoporosis and a debilitating fracture later in life. Arteries become stiff and hard as they can’t get rid of calcium from their walls, leading to atherosclerosis and heart disease.
There are two forms of vitamin K: K1 and K2. K2 is the more physiologically active of the two forms, but much more challenging to get in your diet. Vitamin K1 comes from eating green leafy vegetables and is fairly easy to get from food. Both forms are beneficial to your health.
How much Vitamin K1 do you need for your bones and arteries?
- The minimum for proper clotting is around 100 mcg of vitamin K1 per day (90mcg for women, and 120 mcg for men). Many Americans don’t even achieve this minimal intake.
- Yet for your bones and arteries, they function much better with at least 200 mcg of Vitamin K1 daily, and most experts in this field suggest that for
optimumfunction you get 500 to 1,000 mcg daily.
Here are some great sources of Vitamin K1:
Food Content Measure mcg of K1
Kale, cooked, drained 1 cup 1,062
Collards, cooked drained 1 cup 1,059
Spinach, cooked (or ~7 cups raw) 1 cup 889
Beets, cooked 1 cup 697
Broccoli, cooked 1 cup 220
Brussels sprouts, cooked 1 cup 219
Onions, raw 1 cup 207
Parsley 10 sprigs 164
Cabbage, cooked (or ~ 3 cups raw) 1 cup 163
Asparagus, cooked 1 cup 144
Lettuce, iceberg 1/4 head 3
The bottom line is that nearly everyone should be able to meet their needs for Vitamin K1 with food.
However, there is one contraindication to consuming vitamin K, and that applies to people receiving certain anti-coagulation drugs that decrease clotting. The drug warfarin (Coumadin) decreases vitamin K coagulation activity and taking extra vitamin K can block the medication’s action. In a person requiring this form of medication, taking extra Vitamin K could cause life-threatening clot formation. So, for people taking this type of medication, they should speak to their own physician managing their care before trying to increase their vitamin k intake, either from
As noted above, vitamin K2 is the more potent form of vitamin
In the Rotterdam Study with 4800 subjects followed over 10 years, greater dietary vitamin K2 intake is associated with a decreased risk for cardiovascular disease. They compared people with less than 21 mcg of vitamin K2 per day, with 21 to 32 mcg per day, to more than 32 mcg/day. Those with more than 32 mcg per day had 57% less risk for heart disease than those with less than 21 mcg days.
For bone health, studies have shown that people likely need at least 50 mcg of vitamin K2 per day to lower their risk for osteoporosis and bone density loss, and up to 200 mcg might be a more optimal dose for people with osteopenia or heart disease.
In the table below, you can see foods that are high in vitamin K2. Apart from Natto (fermented soy), the amount needed to achieve at least 32-50 mcg a day for a heart disease benefit would be difficult to do with food alone.
You would have to consume a very large amount of saturated fat from either:
- 14 tablespoons of butter
- 5 ounces of raw-unpasteurized cheese that are aged and
probiotic rich(some might call fermented cheese smelly)
- 8 egg yolks
And to reach more than 200 mcg per day vitamin K2 intake to achieve a bone health benefit seems only achievable with a very large serving of natto (fermented soy).
FOOD Serving size Vitamin K2 mcg/100 mg
Natto (fermented soy) 0.5 cups 257
Munster cheese 1.5 ounces 34
Camembert cheese 1.5 ounces 27
Roquefort cheese 1.5 ounces 16
Swiss cheese 1.5 ounces 3.5
Mozzarella cheese 1.5 ounces 1.7
Butter 7 tablespoons 15
Egg yolk (large) 4 15
Animal meat 3.5 ounces 4.5
Fish 3.5 ounces 0.9
Milk 3.5 ounces 1.1
Green vegetables 2/3 cup 0
Sauerkraut 2/3 cup 5
Fruit 2/3 cup 0
Bread 2 slices 0
There is some conversion of vitamin K1 to vitamin K 2 both in the human intestinal tract and intracellularly. The challenge is that the amount of conversion varies from person to person, and it remains unknown if this conversion is adequate to meet the benefits provided by adequate vitamin K2 intake.
Specific drugs block the conversion of vitamin K1 to K2, in
Supplements provide a convenient way to increase intake for both vitamin K1 and K2. You can find vitamin K added to either
While you should be able to meet your needs for vitamin K1 easily enough with green leafy vegetables, unless you enjoy eating ¼ cup of natto daily (this is definitely an acquired flavor), you’ll need to consider a supplement to meet your optimal intake.
Below are the supplements that I use with my patients to boost their vitamin K1 and K2 intake:
- Vitamin D Synergy (Designs for Health): Vitamin D 2000 IU, Vitamin K1 200 mcg.
- Vitamin D Supreme (Designs for Health): Vitamin D 5000 IU, Vitamin K1 500 mcg, Vitamin K2 50 mcg
- OmegAvail Ultra TG w/ Vit D3, K1 & K2 fish oil (Designs for Health— included in both my Brain & Heart pack and my Joint Support Plus pack): EPA and DHA 1000 mg, Vitamin K1 500 mcg, Vitamin K2 25 mcg
- Tri-K (Designs for Health): Vitamin K1 1000 mcg, Vitamin K2 (Menaquinone-4) 1000 mcg, and Vitamin K2 (Menaquinone-7) 50 mcg
- Basic Nutrients 2/Day multivitamin (Thorne): Vitamin K1 200 mcg, Vitamin K2 200 mcg.
For people with advanced osteoporosis, there are studies that have used dramatically higher dosages of vitamin K2 daily to treat bone loss and risk for bone fractures. Dosages up to 15 mg to 45 mg daily have been used, but you should always discuss this dosing option with your own physician to clarify what is the best medical option for you.
Everyone at the minimum should ensure they meet their needs for vitamin K1 and get at least 250 mcg to 1000 mcg daily, something that you should be able to do by eating one cup of green leafy vegetables every day.
For people at high risk for bone loss or heart disease, especially for those who already have been diagnosed with either of these problems, adding vitamin K2 from either food (natto daily) or a supplement is appealing and worth discussing with your own medical provider.
I wish you the best of health!
Steven Masley, MD, FAHA, FACN, FAAFP, CNS
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