Vitamins K2 & D3: Essential Companions for Calcium

It is possible to change the grim narrative behind two of the world’s biggest health issues for all ages—compromised bone and heart health—with just three nutrients.

We are all familiar with calcium serving as the foundation of healthy bones, but it is also known that excessive calcium supplementation can lead to increased cardiovascular risks. Vitamin K2 as MK-7 (menaquinone-7) is the answer to making this nutrition staple more effective. K2 as MK-7 is a newly recognized vitamin shown in clinical studies to support bone and cardiovascular health by activating proteins that help the body to properly utilize calcium.

Few nutrients work better together than Vitamins K2 and D3. While K2 is required to activate K-dependent proteins such as osteocalcin (OC) for bone health and matrix GLA protein (MGP) to inhibit soft tissue calcification, D3 is needed for the creation of these proteins.

Supplementing with products that combine Vitamins K2 and D3 is crucial for those seeking optimal bone and cardiovascular health, and, unfortunately, those numbers are staggering:

  • Health data compiled from more than 190 countries show heart disease remains the number one-ranked global cause of death: 17.3 million each year.1 That number is expected to rise to more than 23.6 million by 2030.
  • The International Osteoporosis Foundation reports that osteoporosis causes more than 8.9 million fractures annually worldwide, or 1 every 3 seconds. Additionally, 1 in 3 women over age 50 and 1 in 5 men over age 50 will experience osteoporotic fractures.

To have any chance at reducing those numbers, it is essential to combine Vitamin K2 as MK-7 with Calcium and D3.

Deciphering K Confusion

K vitamins are actually a “family” of vitamins made up of two important forms: Vitamin K1 (phylloquinone) and Vitamin K2 (menaquinone). Think of K1 and K2 as fraternal twins. They share similarities, such as working in the liver to contribute to blood clotting, and chemically, they share a quinone ring called menadione. But that is where their similarities end.

Vitamin K2 has several molecules, called menaquinones, which makes it available beyond the liver for other systems, such as the bones and vasculature.

Put simply: Vitamin K2 can do what K1 cannot.

Adding to the K confusion: there are actually multiple forms of K2. The two most com mon forms in supplements are K2 as MK-4 (menaquinone-4) and K2 as MK-7 (menaquinone-7). Due to its longer side chain, MK-7 is more bioavailable and has a much longer half life in the body than MK-4. Further, it is able to do this with a smaller, less-frequent dose (daily microgram for MK-7 over multiple daily milligram doses for MK-4).2-4

Vitamin K2 as MK-7 activates special proteins, allowing the body to properly utilize calcium.

Two of these proteins are OC and MGP. The former attracts calcium where it is needed most, namely into bones and teeth; the latter keeps calcium out of places where it can do harm, namely arteries and soft tissues.

Vitamin D3 is required for the creation of these important proteins, but they remain inactive without adequate Vitamin K2 as MK-7. Optimal vitamin K2 intake is crucial for building strong bones and teeth, while simultaneously avoiding calcium plaque buildup, thus keeping the risk and rate of calcification as low as possible.2-4

The Proven Benefits of Vitamin K2 as MK-7

Any discussion of how K2 keeps hearts and bones healthy through life must clarify one significant point: these studies were performed using a proprietary and patented MenaQ7® Vitamin K2 as MK-7 from NattoPharma, and these results cannot be claimed by any other K2 on the market.

In fact, MenaQ7® has been the source material for 19+ published human clinical trials confirming efficacy and safety in healthy and patient populations, in adults as well as children.

Here is brief sample of some of the most substantial findings:

  • Adult Cardiovascular Health: The first intervention trial to examine Vitamin K2 as MK-7 as a heart-support nutrient was a 3-year study of 244 healthy postmenopausal women. Results confirmed that a daily 180mcg dose of MenaQ7® not only inhibited age-related stiffening of the artery walls, it made a statistically significant improvement in vascular elasticity. 5

According to the researchers, the data demonstrated that a nutritional dose of vitamin K2, in fact, promotes cardiovascular health. No other compound to date has been shown to deliver the same cardiovascular protection as Vitamin K2 as MK-7.

  • Adult Bone Health: A groundbreaking study published in Osteoporosis International in March 20136 confirmed the bone-health benefits of Vitamin K2 as MK-7. The 3-year study of 244 healthy postmenopausal women showed a daily 180mcg dose of MenaQ7 resulted in improved bone mineral content and density, as well as bone strength.
  • Children’s Bone Health: A 2009 study of healthy children aged 6-10 years showed that 45mcg of MenaQ7® K2 / day resulted in more active osteocalcin, leading to stronger, denser bones.7

Also of note, a study published in Food & Function established that children and adults 40+ express the greatest K deficiency and had the strongest response to MenaQ7® K2 supplementation (45 mcg for children; 90 mcg from adults).8 In fact, the study showed that children have an 8-10x greater need for K2 due to higher levels of inactive osteocalcin.

Combining K2 as MK-7 with D3

The global population, especially in children, has shown significant Vitamin K2 deficiencies9, even among those boasting healthy diets. That makes Vitamin K2 supplementation, especially with D3, crucial.

A pilot study published last year in Nutrients highlighted how reduced intakes are believed to correlate to increased bone-related injuries for children. This recent research has shown when vitamins D and K are insufficient in children, they tend to be more at risk for low-energy fracture (such as what occurs when tripping or falling).10

NattoPharma has also examined this important combination, providing MenaQ7® Vitamin K2 as MK-7 to researchers:

A 2013 study of children and teens with a blood-bone condition called Thalassemic Osteopathy (TOSP) were given MenaQ7 ® K2 (50 mcg) and vitamin D (5 mcg calcitriol) daily and found that the combination clearly had a positive effect on the bone mineral density during a one-year period.11

Another study published in 201312 examined the influence of Vitamin K2 administration on vessel calcification in 3.- 5. stage chronic kidney disease (CKD) patients over 6 months. A daily dose of 90 mcg of MenaQ7® K2 plus vitamin D or vitamin D alone was given to patients, and the K2/D group showed a slower progression of calcification.

According to researchers, the progression of coronary artery calcification index (CAC) and common carotid intima media thickness (CCA-IMT)—both markers of calcium deposits in arteries detected with computerized tomography—showed a slower progression of the calcification in the MenaQ7®/vitamin D group than in the D-alone group, highlighting the importance of this vitamin combination.


Without question, Vitamins K2 and D3 must be a part of everyday supplementation. What makes both nutrients so effective is they fully optimize calcium. Therefore, K2 as Menaquinone-7 and Vitamin D3 must work as partners in formulation. The research is there.

Vitamin K2 has all-star representation with MenaQ7®, the only clinically documented K2 as MK-7 shown to deliver on the promise of helping an aging population keep their bones and arteries healthy.


  1. Heart Disease and Stroke Statistics — 2015 Update: A Report From the American Heart Association.
  2. Rheaume-Bleue K. Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save our Life. 2013. Harper; Reprint edition.
  3. Braam LA et al. Thrombosis and Haemostasis. 2004.91(2): 373-80.
  4. Schurgers LJ et al. Thrombosis and Haemostasis. 2008.100(4): 593-603.
  5. Knapen MHJ et al., “Menaquinone-7 supplementation improves arterial stiffness in healthy post menopausal women: double-blind randomised clinical trial,” Thrombosis and Haemostasis. Published online ahead of print February 19, 2015.
  6. Knapen MHJ et al. Osteoporos Int. 2013 Sep;24(9):2499-507.
  7. van Summeren MJ, et al. Br J Nutr. 2009 Oct;102(8):1171-8. doi: 10.1017/S0007114509382100. Epub 2009 May 19.
  8. Theuwissen E., et al. Food Funct. 2014 Feb;5(2):229-34. doi: 10.1039 c3fo60464k.
  9. Shea MK et al. J Nutr. 2011 Aug;141(8):1529-34.
  10. Popko J, et al. Nutrients 2018, 10(6), 734.
  11. Ozdemir MA et al. J Pediatr Hematol Oncol. 2013;35(8):623-7.
  12. Kurnatowska I, et al. Pol Arch Int Med. 2015 Jul 15. pii: AOP_15_066.

Christopher Speed, MND, ADP
Senior Vice President of Sales & Marketing with NattoPharma

Leave a Reply