Vitamin K2 and Bone Health: What You Need to Know
When it comes to maintaining strong, healthy bones, calcium and vitamin D tend to get most of the attention. But there’s another vitamin that plays a role in how the body uses calcium: vitamin K.
Vitamin K comes in several forms, with vitamin K1 and vitamin K2 being the two main groups. Vitamin K1 is found primarily in leafy green vegetables and is best known for its important role in normal blood clotting. Vitamin K2, on the other hand, refers to a group of compounds called menaquinones, including MK-4 and MK-7, which are involved in activating proteins that help regulate calcium in the body. One form in particular, MK-7, is commonly found in supplements.
Why MK-7?
Although MK-4 and MK-7 are both forms of vitamin K2, they behave differently in the body. MK-7 is more readily available in the bloodstream and has a much longer half-life, meaning it stays in circulation for much longer than MK-4 or vitamin K1. This allows for more sustained delivery of vitamin K to tissues outside the liver, including bone and blood vessels.
This longer-lasting activity is one reason MK-7 is commonly used in vitamin K2 supplements and has become a particular focus of research on bone and calcium metabolism.
Here are a few great supplement options:
AOR Vitamin K2 - Capsules combine both MK-4 and MK-7 for greater effectiveness
CanPrev K2 - features MK-7 and is available both in drops and soft gels providing 120 mcg per daily dose.
Ortho Molecular Products Vitamin D3 with K2 combines 1,000 IU of vitamin D3 with 10 mcg of research-backed MenaQ7® PRO MK-7 to support bone health, calcium utilization and healthy blood circulation in a convenient, tasteless liquid.
Why Is Vitamin K Important For Bone Health?
Bone is a living tissue that is constantly being broken down and rebuilt. Vitamin K helps activate proteins involved in this process, including osteocalcin, a protein produced by bone-building cells. Once activated, osteocalcin can bind calcium and help support its incorporation into bone.
Vitamin K also activates matrix Gla protein (MGP), which helps regulate calcium deposition in the body. And this is where vitamin K’s role extends beyond bone health. MGP is also found in blood vessels, where it is involved in regulating calcium deposition. This has sparked interest in vitamin K's potential role in arterial and cardiovascular health, particularly because excessive calcium accumulation in the arterial walls can contribute to arterial stiffness.
How Do Vitamin D, Calcium And K Work Together?
These nutrients have different jobs:
| Nutrient | Role In Bone Health |
| Calcium | Provides the mineral structure of bone |
| Vitamin D | Helps the body absorb & regulate calcium |
| Vitamin K | Helps activate proteins involved in bone formation & mineralization |
| Protein | Provides building blocks for bone tissue |
Vitamin D is particularly important because it helps the body absorb calcium. Vitamin K, meanwhile, is involved in activating proteins that help incorporate minerals into bone.
Should You Take Vitamin K2 With Vitamin D?
The combination makes biological sense, but that doesn't mean a K2 supplement is essential whenever vitamin D is taken. Vitamin D helps the body absorb calcium, while vitamin K helps activate proteins involved in calcium regulation and bone mineralization.
For bone health, it makes more sense to look at the whole picture:
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Are you getting enough calcium?
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Is vitamin D adequate?
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Are you eating enough protein?
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Are you doing resistance and weight-bearing exercise?
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Are you getting enough magnesium and other nutrients?
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Are there hormonal, digestive or medication-related factors affecting bone health?
Canadian guidelines recommend progressive resistance training and balance/functional exercise, along with adequate calcium and vitamin D intake.
What Foods Contain Vitamin K?
Vitamin K is naturally found in a variety of foods, making it possible to get this important nutrient through your diet.
Vitamin K1 is abundant in leafy green vegetables such as kale, spinach and broccoli. Vitamin K2 is found in foods including fermented foods, certain cheeses, eggs and meat. Natto, a fermented soybean food, is particularly rich in MK-7.
Can Vitamin K2 Interact With Blood Thinners?
Vitamin K can interact with warfarin (Coumadin), a commonly prescribed anticoagulant. People taking warfarin should generally keep their vitamin K intake consistent rather than suddenly adding or removing a high-dose K2 supplement. Changes in vitamin K intake can affect how the medication works.
If you take warfarin, speak with your doctor or pharmacist before starting a vitamin K2 supplement. Anyone taking medication that affects blood clotting should also check with their healthcare provider before adding a concentrated vitamin K supplement.
What Else Can You Do To Support Strong Bones?
K2 is one part of the equation. Bone health is influenced by nutrition, hormones, physical activity, muscle strength and overall health.
Some of the most practical things you can do include:
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Eat adequate calcium-rich foods
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Get sufficient vitamin D
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Include protein regularly throughout the day
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Do resistance training and weight-bearing activity
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Include balance and functional exercises
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Avoid smoking and excessive alcohol
Osteoporosis Canada also emphasizes calcium, vitamin D, protein, magnesium and vitamin K as important bone-building nutrients.
Frequently Asked Questions About Vitamin K
How Much Vitamin K Should You Take Daily?
Health Canada’s recommended adequate intake for adults is 90 mcg per day for women and 120 mcg per day for men. These recommendations apply to total vitamin K intake from food and supplements, and individual needs may vary depending on health status and diet.
For detailed, age-specific recommendations, refer to Health Canada’s Dietary Reference Intakes for Vitamins.
When Should I Take K?
Vitamin K is fat-soluble, meaning it is absorbed along with dietary fat. Taking it with a meal that contains healthy fats may help support absorption.
Are There Any Side Effects Or Precautions When Taking Vitamin K?
Vitamin K is generally well tolerated at typical intake levels. However, it can interact with anticoagulant medications such as warfarin, which work by interfering with vitamin K’s role in blood clotting. If you take a blood thinner, speak with your healthcare provider before starting or changing a vitamin K supplement. Consistency in vitamin K intake is particularly important when taking warfarin.
Disclaimer: The information provided in this blog is for educational purposes only and should not be considered as a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of your doctor regarding any medical condition, and before implementing dietary changes, or supplementation.