Vitamin K
Description
Vitamin K is a group of fat-soluble vitamins that are vital for various bodily functions. The two primary forms are Vitamin K1 (phylloquinone), found mainly in plant foods, and Vitamin K2 (menaquinone), found in animal products and fermented foods, and also produced by gut bacteria. Both forms are crucial, but K2 is gaining recognition for its broader systemic benefits. Its most well-known function is its role in blood coagulation. Vitamin K acts as a coenzyme for the enzyme gamma-glutamyl carboxylase, which is necessary for the activation of several clotting factors in the liver. Without adequate Vitamin K, the blood's ability to clot effectively is impaired, leading to excessive bleeding. Beyond clotting, Vitamin K is also critical for bone health. It activates proteins like osteocalcin, which helps bind calcium to the bone matrix, and Matrix Gla Protein (MGP), which prevents calcium deposition in soft tissues like arteries. This dual action contributes to strong bones and cardiovascular health, preventing arterial calcification.
Sources
Leafy green vegetables (kale, spinach, collard greens, Swiss chard)BroccoliBrussels sproutsCabbageNatto (fermented soybeans - particularly rich in K2)Meat (liver, chicken)EggsHard cheesesFermented foods
Cheapest Vitamin K supplements
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Value Vitamin K Supplements
Timing & Intake
AnytimeWith foodTake with Fat-containing meal
As Vitamin K is fat-soluble, it is best absorbed when taken with a meal containing some fat.
Daily Intake
RDA (Men)120 mcg
RDA (Women)90 mcg
RDI120 mcg
Optimal Dosage
Minimum100 mcg
Maximum200 mcg
Safety & Toxicity
Toxicity Effectno known toxicity
Goals
Anti-Aging
Impact
Highest effect
Typical dose:100–500 mcg
Vitamin K2, in particular, activates proteins like osteocalcin and Matrix Gla Protein (MGP). Osteocalcin helps bind calcium to the bone matrix, while MGP prevents calcium from depositing in soft tissues like arteries and blood vessels. This dual action is fundamental for maintaining both skeletal strength and cardiovascular flexibility with age.
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Bone Health
Impact
Highest effect
Typical dose:90–400 mcg
Specifically, Vitamin K2 (menaquinone) is critical for directing calcium into the bones and teeth and away from soft tissues like arteries. It activates osteocalcin, a protein that incorporates calcium into bone, and Matrix Gla Protein (MGP), which prevents vascular calcification.
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Cardiovascular Support
Impact
Highest effect
Typical dose:90–200 mcg
While often known for blood clotting (Vitamin K1), the K2 form (specifically MK-7) is vital for cardiovascular health. It activates proteins that inhibit calcium deposition in arterial walls, a key factor in atherosclerosis and arterial stiffening. This helps maintain blood vessel elasticity and function.
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General Health
Impact
Highest effect
Typical dose:100–200 mcg
Primarily in its K2 form, this vitamin is crucial for proper calcium metabolism. It activates proteins that help bind calcium to the bone matrix and prevent its accumulation in soft tissues like arteries, where it can cause calcification. It is an essential partner to Vitamin D supplementation.
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Heart Health
Impact
Highest effect
Typical dose:90–300 mcg
The K2 form (specifically MK-7) activates matrix Gla-protein (MGP), the most potent inhibitor of vascular calcification. By ensuring calcium is deposited in bone rather than soft tissues, Vitamin K2 directly contributes to maintaining arterial flexibility and preventing stiffness.
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Interactions
Positive Interactions
Calcium
Vitamin K helps activate proteins (like osteocalcin) that are essential for binding Calcium into the bone matrix, promoting stronger bones.
Vitamin D
Vitamin K and Vitamin D work synergistically to regulate Calcium metabolism, promoting bone mineralization and preventing arterial calcification. Vitamin D aids Calcium absorption, while Vitamin K directs it to the bones.
Magnesium
Magnesium is involved in bone formation and works with Vitamin K and Vitamin D to support overall bone health and mineral density.
Negative Interactions
Product stats
Price per product
Average$35.92
Median$31.98
Price per serving
Average$0.83
Median$0.77
Price per 100 mcg
Average$0.45
Median$0.47
Price distribution
Price per serving distribution
Price per 100 mcg
Reference amount: 100 mcg
Forms
Paired ingredients
Ingredient forms
Menaquinone-7 (262) 92
Menaquinone-7 (MK-7) is a long-chain menaquinone, a type of Vitamin K2, primarily found in fermented foods like natto. It is known for its superior bioavailability and longer half-life compared to other K2 forms and K1, allowing for more sustained physiological activity. MK-7 activates Matrix Gla Protein (MGP) to prevent arterial calcification and osteocalcin to promote bone mineralization, making it crucial for cardiovascular and bone health.
Pros
- Highly bioavailable and long half-life for sustained action.
- Significant impact on bone health by promoting calcium incorporation.
- Strong preventative effect against arterial calcification for cardiovascular health.
Cons
- Can be more expensive than other Vitamin K forms.
- Primarily found in a few specific fermented foods, making dietary intake challenging without supplementation.
Per product
Avg$34.01
Med$29.99
Per serving
Avg$0.84
Med$0.77
Per 100 mcg
Avg$1.66
Med$0.79
Price distribution
Phytonadione (206) 80
Phytonadione is the synthetic form of Vitamin K1 (phylloquinone) and is also naturally abundant in green leafy vegetables. Its primary physiological role is as a co-factor for gamma-glutamyl carboxylase, an enzyme necessary for the synthesis of coagulation factors (II, VII, IX, X) in the liver. It is crucial for hemostasis (blood clotting) and is often administered therapeutically to reverse anticoagulant effects or treat K1 deficiency. While essential for clotting, its role in bone and cardiovascular health is less pronounced than that of Vitamin K2 forms.
Pros
- Essential for normal blood clotting and prevention of hemorrhage.
- Readily available in a wide range of common dietary sources.
- Safe at recommended daily allowance levels.
Cons
- Less effective for bone and cardiovascular health compared to Vitamin K2 forms.
- Shorter half-life than MK-7, limiting systemic benefits.
Per product
Avg$28.57
Med$24.50
Per serving
Avg$0.65
Med$0.53
Per 10 mcg
Avg$0.10
Med$0.06
Price distribution
Menaquinone-4 (50) 78
Menaquinone-4 (MK-4) is a short-chain menaquinone, a form of Vitamin K2, found in animal products like meat, eggs, and dairy. Unlike other menaquinones, MK-4 can be synthesized in the body from K1 in certain tissues, although dietary intake is also a source. It has a rapid turnover and tissue-specific functions, particularly in brain, testes, and pancreas, and plays a role in bone metabolism.
Pros
- Rapidly absorbed and utilized in the body.
- Important for specific tissue functions, including brain and bone health.
- Can be synthesized endogenously from K1 in certain tissues.
Cons
- Short half-life, requiring higher or more frequent dosing for sustained systemic effects.
- Less effective for preventing arterial calcification than MK-7 at typical supplemental doses.
Per product
Avg$35.93
Med$33.64
Per serving
Avg$0.85
Med$0.96
Per 100 mcg
Avg$0.64
Med$0.62
Price distribution
Vitamin K1 (42) 80
Vitamin K1, or phylloquinone, is the most common dietary form of Vitamin K, predominantly found in plant-based foods such as spinach, kale, and broccoli. Its primary function is in the liver, where it acts as a co-factor for the enzyme gamma-glutamyl carboxylase, which is necessary for the activation of several proteins involved in blood coagulation. While crucial for clotting, its role in bone and cardiovascular health is less pronounced than that of Vitamin K2.
Pros
- Essential for blood clotting and prevention of hemorrhage.
- Widely available and easily obtainable through a healthy diet.
- Generally safe at recommended dietary intake levels.
Cons
- Less effective for bone health and preventing arterial calcification compared to K2 forms.
- Shorter half-life than MK-7, limiting sustained systemic benefits.
Per product
Avg$47.77
Med$45.50
Per serving
Avg$1.09
Med$0.80
Per 100 mcg
Avg$1.33
Med$0.79
Price distribution
Vitamin K2 (29) 90
Vitamin K2 is a collective term for a series of menaquinones (MK-n) distinguished by the length of their isoprenoid side chains (e.g., MK-4, MK-7). Found in fermented foods and animal products, K2 is vital for activating Matrix Gla Protein (MGP) and osteocalcin, which are key proteins involved in calcium regulation. This dual action helps prevent arterial calcification and promotes proper bone mineralization, offering significant benefits for cardiovascular and skeletal health.
Pros
- Crucial for both bone and cardiovascular health.
- Prevents arterial calcification by directing calcium appropriately.
- Long-chain forms (like MK-7) have high bioavailability and extended action.
Cons
- Less common in typical Western diets than K1, often requiring supplementation.
- Potential interaction with blood thinners.
Per product
Avg$33.02
Med$30.36
Per serving
Avg$0.79
Med$0.60
Per 100 mcg
Avg$0.81
Med$0.67
Price distribution
Menaquinone (28) 88
Menaquinone refers to a group of fat-soluble compounds collectively known as Vitamin K2. These compounds are characterized by their isoprenoid side chains of varying lengths (e.g., MK-4, MK-7). Menaquinones are crucial for the activation of proteins involved in calcium metabolism, such as osteocalcin (for bone) and Matrix Gla Protein (MGP, for vascular health), helping to direct calcium to bones and away from soft tissues like arteries.
Pros
- Encompasses highly beneficial forms of K2, vital for bone and heart health.
- Crucial for proper calcium utilization in the body.
Cons
- A broad term, specific benefits and bioavailability depend on the particular menaquinone form (e.g., MK-4 vs. MK-7).
- Less common in typical Western diets than K1.
Per product
Avg$28.99
Med$24.23
Per serving
Avg$0.71
Med$0.56
Per 100 mcg
Avg$0.64
Med$0.37
Price distribution
Cabbage (12) 65
Cabbage is a leafy green vegetable that is a good natural source of Vitamin K1 (phylloquinone). While it provides essential Vitamin K, the amount per serving is typically lower than in concentrated supplements or certain other leafy greens (like kale or spinach). Regular consumption of cabbage contributes to meeting daily Vitamin K requirements, supporting blood clotting and general health, while also providing fiber and other vitamins.
Pros
- Natural food source of Vitamin K1 and other essential nutrients.
- Provides fiber and antioxidants, contributing to overall dietary health.
- No direct risk of overconsumption of K1 from food sources.
Cons
- Lower concentration of Vitamin K compared to supplements, primarily K1 (less K2).
- Absorption of K1 from plant sources can be variable.
Per product
Avg$45.29
Med$48.49
Per serving
Avg$0.89
Med$0.92
Per 100 mcg
Avg$0.66
Med$0.62
Price distribution
K1 (11) 80
K1, or Vitamin K1, is the form of Vitamin K found predominantly in plants, specifically green leafy vegetables. Its most well-known function is its indispensable role in the liver's synthesis of blood clotting factors, which are essential for preventing excessive bleeding. While its primary action is related to coagulation, K1 also plays a lesser role in bone metabolism compared to K2.
Pros
- Essential for blood clotting and prevention of hemorrhage.
- Readily available in a wide range of common dietary sources.
- Safe at recommended daily allowance levels.
Cons
- Less effective for bone and cardiovascular health compared to Vitamin K2 forms.
- Shorter half-life than MK-7, limiting systemic benefits.
Per product
Avg$36.78
Med$34.29
Per serving
Avg$0.89
Med$1.01
Per 100 mcg
Avg$0.69
Med$0.72
Price distribution