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Product Spotlight - EnDuro D



The word synergy “refers to when an interaction of elements produces an effect that is greater than the effect that would have resulted from simply adding up the effects of each individual element. In other words, it is what happens when a combination of things produces an effect or result that is said to be ‘greater than the sum of its parts.”

Vitamins D3 and K2—both essential, fat-soluble nutrients— are a perfect example of synergy. While each of these extraordinarily beneficial vitamins supply many individual benefits, they rely on each other to function optimally, especially in regards to bone and arterial health.

The researched benefits of vitamin D3 are so plentiful that it would take every page of all 126 issues of Endurance News (and most likely many more than that) to discuss them all (do a Google search on “vitamin D benefits” and you’ll probably be online for a month or so). In fact, there is no other nutrient that I know of—with the exception of magnesium—that is involved in more aspects of human health than vitamin D3.

The benefits from vitamin D3 supplementation are to support the immune system proper utilization of calcium to optimize bone density and overall bone health normalize blood pressure and support cardiovascular health and so much more.

Vitamin K2 works with vitamin D3 for supporting both bone and cardiovascular health by activating a protein called osteocalcin, which helps keep calcium out of the arteries while increasing the amount of calcium in the bones (teeth as well). Vitamin K2, working alongside vitamin D3, also promotes healthy glucose metabolism to maintain proper blood sugar levels thus helping protect against type 2 diabetes.

While these are the primary benefits of vitamins D3 and K2, there are many other benefits, far too many to list here. Everyone* will benefit from supplementation of vitamin D3 and vitamin K2, the dynamic duo for numerous areas of human health.

*Vitamin K2 is not recommended for people on blood-thinning medications, unless approved by their primary health care provider.


Vitamin D3................. 50 mcg (2,000IU)

Vitamin K2...........................1,680 mcg
Menaquinone 4 (MK-4).....1500 mcg
Menaquinone 7 (MK-7).......180 mcg


D2 (ergocalciferol)
The plant-derived form.

D3 (cholecalciferol)
The sun-derived form, animal-derived (lanolin) form, and the form that is believed to effectively raise bodily levels of active vitamin D better than D2.

NOTE: In 1919, German researcher Adolf Windaus discovered three forms of vitamin D: D1, D2, and D3. When it was found that D1 was actually a mixture of compounds instead of a pure vitamin D product, the term D1 was dropped.


K1 (phylloquinone)
The plant-derived form, and the main form of vitamin K in the diet. Vitamin K1 is poorly absorbed, with less than 10% absorption rates.

K2 (Menaquinone)
The often found in foods that contain fat and suggested to be a better-absorbed form than K1 that also circulates in the blood longer than K1.

NOTE: Vitamin K2 has a number of menaquinone (MK for short) subtypes, with the most beneficial ones being MK-4, and MK-7. Research on the MK-4 subtype of vitamin K2 used 1500 mcg/day.

Studies on MK-7 used 180 mcg/ day. Also, Dr. Dennis Goodman, author of Vitamin K2: The Missing Nutrient for Heart and Bone Health, suggests amounts between 150 to 180 mcg/day of MK-7. These are the amounts found in EnDuro D.

Download Issue 126 PDF

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