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What Is the Vitamin D/Vitamin K Connection?

Vitamin D Feature Image


Like most health-minded women, you’ve probably been faithful in taking your calcium and vitamin D supplements for your bone and heart health if you aren’t consuming enough of these nutrients in your diet. Now, research is showing that we’ve been missing an important part of the puzzle: Vitamin K. As it turns out, we may have been doing more harm than good if we haven’t been including this little-known nutrient in our nutrition regimen.

Vitamin K works in synergy with vitamin D, and many experts are advising that individuals should always take vitamin K when supplementing with vitamin D, particularly if also taking calcium supplements. Here’s why: One of vitamin D’s roles is to help the body absorb calcium, moving it from the gut to the blood, and then vitamin K helps to direct the calcium to our bones and away from our soft tissues (e.g., arteries, veins, skin, etc.).

As you can see, this is an extremely important pair! They work together to help maintain both our bone health and our cardiovascular health.

A Closer Look at Vitamin D

Vitamin D is a very important nutrient for proper body function. It is unique in that our skin has the ability to make it from sunlight. As our bare skin is exposed to ultraviolet B rays, the nutrient is synthesized at different rates, depending on where you live in the world (northern latitudes are worse), the amount of skin exposed, the color of your skin and the time of day. The Vitamin D Council suggests that “you only need to expose your skin for around half the time it takes for your skin to turn pink and begin to burn.”

While this is a wondrous natural process, most of us do not get enough sun exposure due to cold winters, extensive hours working indoors and fear of skin damage. If this is your situation, you have two more options to help you get the recommended amounts of vitamin D.

In addition to sunlight exposure, you can obtain vitamin D in limited amounts from your diet, though only a few foods naturally contain it. The main, quality, food sources include:

  • Salmon
  • Sardines
  • Cow’s Milk
  • Tuna
  • Eggs
  • Shitake Mushrooms

The George Mateljan Foundation, WHFoods.com.

A third option for obtaining vitamin D is through supplementation. Vitamin D3 may be your best option, as that is the form that your body makes from sun exposure. These supplements come in several forms, including softgels, drops, vegetable capsules and chewables. Here are a couple of our best sellers at Natural Healthy Concepts:

Vitamin D Intensive NutritionVitamin D Ortho Molecular









       D-2000 by Intensive Nutrition               Liquid Vitamin D3 by Ortho Molecular

Vitamin D Natural Healthy Concepts

Vitamin D3 Concepts 5000 by Natural Healthy Concepts


Vitamin D RDA
Recommended Dietary Allowance (RDA) from the Food and Nutrition Board at the Institute of Medicine

Organizations differ on their recommendations for vitamin D intake. For example the Vitamin D Council suggests greater amounts each day. Ask your healthcare professional what may be best for you!

Health Benefits Related to Vitamin D

Ongoing research on vitamin D during the first decade of the 2000s revealed many health benefits and gene influences. Until that time, it was relatively unknown. Some of its beneficial roles include its help with:

  • Bone Strength
  • Bone Health
  • Cardiovascular Function
  • Brain Development
  • Immune Function
  • Respiratory Function
  • Muscle Function
  • Cellular Communication
  • General Good Health

The most talked about benefit of vitamin D is its relation to bone health and function. It plays a huge role in calcium and phosphorous absorption, and in managing calcium in the blood and bones. As you can see here, there are many other potential health benefits of vitamin D!

As the Vitamin D Council explains, however, “to get the most benefit from vitamin D, you must have other cofactors in your body,” including vitamin K.

More About Vitamin K

This important fat-soluble nutrient is actually a team of chemicals that function as a coenzyme in the processes of blood clotting, bone metabolism and other functions. It is unique in that it is the only vitamin produced within the human body, but not by the body. Roughly 75% of the amount absorbed each day is produced by the “good” bacteria in the intestine, while the remaining amount comes from dietary sources. Generally, the total amount absorbed each day is the minimum amount required. (Source)

However, vitamin K absorption is dependent on normal gallbladder function and liver health, and it is not stored in the body. As Julius G. Goepp, MD, notes in his article, “Vitamin K’s Delicate Balancing Act”: “Taken together, these factors explain why the net daily balance of vitamin K is so delicate. As people live longer and vitamin K-dependent processes are discovered in more and more tissues, more scientists are suggesting that vitamin K is needed in larger quantities than what was once thought, particularly in aging adults.”

Since it is rapidly metabolized and excreted, not much vitamin K is stored in our tissue or blood.

Its two main forms are:

  • Vitamin K1 (phylloquinone): This is a cofactor for coagulation factors. It has a relatively short half-life, so it is cleared from the blood and by the liver rapidly. K1 is found primarily in fresh green vegetables.
  • Vitamin K2 (menaquinones): This form is essential for healthy bones, as it activates osteocalcin, a protein hormone that plays a role in the process of binding calcium into your bone matrix. K2 also activates proteins that work to form new bone cells. Additionally, this is the substance that helps keep calcium from building up in your arteries and supports arterial elasticity. K2 remains biologically active in the body longer than K1. It is found in small amounts in fermented foods like tempeh, miso, cheese, natto and sauerkraut, and in some animal-based foods.

Some excellent sources of vitamin K include:

  • Kale
  • Spinach
  • Mustard/Collard/Beet/Turnip Greens
  • Swiss Chard
  • Broccoli
  • Brussels Sprouts
  • Romaine Lettuce
  • Asparagus
  • Kiwi

The George Mateljan Foundation, WHFoods.com.

Unfortunately, vitamin K1 is most commonly found in foods, leaving a nutritional gap when it comes to K2, unless you eat a good amount of fermented foods each day. The other option for obtaining vitamin K2 is through supplementation. These are a couple of our best sellers here at Natural Healthy Concepts:

Vitamin K Life Extension Vitamin K NOW








             Super K by Life Extension                                  Vitamin K-2 by NOW


Vitamin K RDA
Recommended Dietary Allowance (RDA) from the Food and Nutrition Board at the Institute of Medicine

Health Benefits Related to Vitamin K

Vitamin K is needed by the body for good health. Some of its beneficial roles include its assistance with:

  • Bone Strength: This nutrient directs calcium to your skeleton, where it is needed, so it is deposited in the correct areas (i.e., not in your arteries or other soft tissue).
  • Bone Metabolism: Vitamin K plays an important role in modulating bone cell growth.
  • Cardiovascular Health:  A protein called Matrix Gla needs vitamin K to preform its role in preventing calcium from depositing in our soft tissues. In addition, a recent study showed that “high intake of vitamin K2 was significantly associated with a reduced risk of peripheral artery disease in hypertensive participants.”
  • Blood Clotting: One of the proteins it makes, prothrombin, plays a big role in the clotting of our blood.

Considering all of these complementary benefits, it’s no wonder scientists are encouraging the use of vitamin K with vitamin D!

Working in Synergy

More recent research into vitamin K has shown that it can greatly enhance vitamin D’s benefits and that vitamin D actually has a dependency on vitamin K. In fact, low vitamin K2 levels cause vitamin D toxicity, which can lead to inappropriate calcification and then to hardening of the arteries. The reason is due to the fact that taking in vitamin D causes the body to create more vitamin K2-dependent proteins that move calcium throughout the body. If you do not have enough vitamin K2, those proteins remain inactivated. So remember, if you supplement with vitamin D, you’re creating an increased demand for K2. (Source)

Vitamin K works in synergy with vitamin D in this main way: Vitamin D helps the body absorb calcium, moving it from the gut to the blood. Then vitamin K steps in to help move calcium into the proper areas of the body, such as your bones and teeth, and to help remove calcium from areas where it shouldn’t be, such as your arteries, veins, skin and other soft tissues. Without vitamin K, inappropriate calcification can lead to health issues. These two nutrients work together so well to help keep our bones strong and our hearts healthy.

So, remember, if you do opt for a vitamin D supplement, you also need to take vitamin K2.

In addition, research is now showing that calcium should not be taken alone. This mineral needs its complementary nutrients, including magnesium, and vitamins D and K. In her book, “Vitamin K2 and the Calcium Paradox,” popular Canadian health expert and biologist Kate Pheaume-Bleue explains:

Millions of women take calcium supplements to fight osteoporosis. Multiple studies now show that this leads to heart attack and stroke as that added calcium builds up in arteries. This is the Calcium Paradox: a dangerous accumulation of excess calcium in arteries along with a dangerous lack of calcium in bones and teeth. Vitamin K2 puts calcium back in its place!

Did you know about the connection between vitamin D and vitamin K? Share your thoughts in the comments section below!