Vitamin K2
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NUTRIENT FACTS
Nutrient Type
YES
ATC Code
No
Deficiency Diseases
YES
Dietary Sources
YES
Summary
Vitamin K2 helps direct calcium to bones and teeth, which strengthens them, and away from arteries, which prevents hardening of the arteries.
You can get Vitamin K2 from animal products like liver and egg yolks, and fermented foods like cheese and natto, which is a fermented soybean dish.
A lack of Vitamin K2 can lead to weak bones, increasing fracture risk, and calcium buildup in arteries, raising heart disease risk.
There is no specific upper limit for Vitamin K2, but adults should aim for 90-120 micrograms of Vitamin K daily from diet, including K2.
Vitamin K2 supplements can interact with blood thinners like warfarin, which prevent clots, so consult a doctor before use.
Frequently Asked Questions
What does Vitamin K2 do?
Vitamin K2 is a vitamin that plays a crucial role in bone and cardiovascular health. It helps activate proteins that regulate calcium deposition, ensuring calcium is directed to bones and teeth rather than arteries. This process supports bone strength and reduces the risk of arterial calcification, which is the buildup of calcium in the artery walls. Vitamin K2 is significant for maintaining healthy bones and preventing heart disease.
How can I get Vitamin K2 from my diet?
Vitamin K2 is found in various foods. Animal-based sources include liver, egg yolks, and dairy products like cheese. Fermented foods, such as natto, which is a traditional Japanese dish made from fermented soybeans, are rich in Vitamin K2. The absorption of Vitamin K2 can be affected by factors like gut health and the presence of dietary fats, which enhance its absorption. A balanced diet including these foods can help maintain adequate Vitamin K2 levels.
How does Vitamin K2 affect my health?
Vitamin K2 deficiency can lead to several health issues. It is essential for bone and cardiovascular health. A deficiency may result in weakened bones, increasing the risk of fractures. It can also lead to calcification of arteries, which is the buildup of calcium in the artery walls, increasing the risk of heart disease. Symptoms of deficiency might include easy bruising and bleeding. Populations at risk include the elderly, individuals with malabsorption issues, and those on long-term antibiotic use.
Who can have low levels of Vitamin K2?
Certain groups are more at risk for Vitamin K2 deficiency. These include the elderly, who may have reduced dietary intake and absorption. Individuals with gastrointestinal disorders, which affect nutrient absorption, are also at risk. People on long-term antibiotic therapy may experience reduced Vitamin K2 levels due to changes in gut bacteria. Additionally, those with poor dietary habits lacking in Vitamin K2-rich foods, such as fermented foods and certain animal products, are at risk.
What diseases can Vitamin K2 treat?
Vitamin K2 is used as a complementary treatment for osteoporosis, which is a condition characterized by weak and brittle bones. It helps improve bone density and reduce fracture risk by activating proteins that bind calcium to bones. Vitamin K2 may also support cardiovascular health by preventing arterial calcification, which is the buildup of calcium in the artery walls. While some studies suggest benefits, more research is needed to confirm the effectiveness of Vitamin K2 in these conditions.
How do I know if I have low levels of Vitamin K2?
Diagnosing Vitamin K2 deficiency involves assessing clinical symptoms and dietary intake. Blood tests measuring levels of undercarboxylated osteocalcin, which is a protein involved in bone metabolism, can indicate deficiency. High levels of this protein suggest insufficient Vitamin K2. Symptoms like easy bruising, bleeding, and bone weakness may also prompt testing. Healthcare providers may consider these factors along with medical history to diagnose a deficiency.
How much supplement of Vitamin K2 should I take?
The daily requirement for Vitamin K2 is not well established, but it is generally included in the overall recommendation for Vitamin K. For adults, the adequate intake for Vitamin K is around 90 micrograms per day for women and 120 micrograms per day for men. These values include both Vitamin K1 and K2. There is no specific upper limit for Vitamin K2, but it's important to get it from a balanced diet rather than supplements unless advised by a healthcare provider.
Will supplements of Vitamin K2 interfere with my prescription medicines?
Yes, Vitamin K2 supplements can interact with certain prescription medications. Vitamin K2 may affect blood clotting, so it can interact with anticoagulant medications, which are drugs that help prevent blood clots. This interaction can reduce the effectiveness of anticoagulants like warfarin, which is a medication used to prevent blood clots. It's important to consult with a healthcare provider before taking Vitamin K2 supplements if you are on anticoagulant therapy to avoid potential complications.
Is taking too much of Vitamin K2 harmful?
Excessive intake of Vitamin K2 can be harmful, especially for individuals on anticoagulant medications like warfarin, which help prevent blood clots. High doses of Vitamin K2 can interfere with these medications, reducing their effectiveness and increasing the risk of clotting. There is no established upper intake level for Vitamin K2, but unnecessary supplementation should be avoided unless recommended by a healthcare provider. It's important to consult a healthcare professional before starting any new supplement.
What is the best supplement for Vitamin K2?
Vitamin K2 comes in several forms, with MK-4 and MK-7 being the most common. MK-4 is found in animal products and has a shorter half-life, which means it stays in the body for a shorter time. MK-7, found in fermented foods, has a longer half-life, allowing for once-daily dosing. MK-7 is often preferred for its longer-lasting effects and better bioavailability, which is the degree to which a substance is absorbed into the bloodstream. Choice depends on dietary preferences and health goals.
Content of Selected Foods
| Food | Milligrams (mg) per serving | Percent DV* |
|---|---|---|
| Natto, 3 ounces (as MK-7) | 850 | 708 |
| Collards, frozen, boiled, ½ cup | 530 | 442 |
| Turnip greens, frozen, boiled ½ cup | 426 | 355 |
| Spinach, raw, 1 cup | 145 | 121 |
| Kale, raw, 1 cup | 113 | 94 |
| Broccoli, chopped, boiled, ½ cup | 110 | 92 |
| Soybeans, roasted, ½ cup | 43 | 36 |
| Carrot juice, ¾ cup | 28 | 23 |
| Soybean oil, 1 tablespoon | 25 | 21 |
| Edamame, frozen, prepared, ½ cup | 21 | 18 |
| Pumpkin, canned, ½ cup | 20 | 17 |
| Pomegranate juice, ¾ cup | 19 | 16 |
| Okra, raw, ½ cup | 16 | 13 |
| Salad dressing, Caesar, 1 tablespoon | 15 | 13 |
| Pine nuts, dried, 1 ounce | 15 | 13 |
| Blueberries, raw, ½ cup | 14 | 12 |
| Iceberg lettuce, raw, 1 cup | 14 | 12 |
| Chicken, breast, rotisserie, 3 ounces (as MK-4) | 13 | 11 |
| Grapes, ½ cup | 11 | 9 |
| Vegetable juice cocktail, ¾ cup | 10 | 8 |
| Canola oil, 1 tablespoon | 10 | 8 |
| Cashews, dry roasted, 1 ounce | 10 | 8 |
| Carrots, raw, 1 medium | 8 | 7 |
| Olive oil, 1 tablespoon | 8 | 7 |
| Ground beef, broiled, 3 ounces (as MK-4) | 6 | 5 |
| Figs, dried, ¼ cup | 6 | 5 |
| Chicken liver, braised, 3 ounces (as MK-4) | 6 | 5 |
| Ham, roasted or pan broiled, 3 ounces (as MK-4) | 4 | 3 |
| Cheddar cheese, 1½ ounces (as MK-4) | 4 | 3 |
| Mixed nuts, dry roasted, 1 ounce | 4 | 3 |
| Egg, hard boiled, 1 large (as MK-4) | 4 | 3 |
| Mozzarella cheese, 1½ ounces (as MK-4) | 2 | 2 |
| Milk, 2%, 1 cup (as MK-4) | 1 | 1 |
| Salmon, sockeye, cooked, 3 ounces (as MK-4) | 0.3 | 0 |
| Shrimp, cooked, 3 ounces (as MK-4) | 0.3 | 0 |
- * DV = Daily Value. The U.S. Food and Drug Administration (FDA) developed DVs to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet. The DV for vitamin K is 120 mcg for adults and children age 4 years and older [17]. FDA does not require food labels to list vitamin K content unless vitamin K has been added to the food. Foods providing 20% or more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet.
Required (or Advised) Daily Intake
| Age | Male | Female | Pregnant | Lactating |
|---|---|---|---|---|
| 0–6 months | 2.0 | 2.0 | - | - |
| 7–12 months | 2.5 | 2.5 | - | - |
| 1–3 years | 30 | 30 | - | - |
| 4–8 years | 55 | 55 | - | - |
| 9–13 years | 60 | 60 | - | - |
| 14+ years | 75 | 75 | 75 | 75 |
