Vitamin K2 (MK-7)
Menaquinone-7
The partner vitamin D3 needs to work properly. K2 MK-7 directs calcium away from arteries and into bones, and plays a direct role in maintaining healthy testosterone levels alongside D3.
What it is
A fat-soluble vitamin found naturally in fermented foods and certain animal products. MK-7 is the most bioavailable and longest-acting form of K2, remaining active in the body for 72 hours compared to just a few hours for other forms.
Why it's in Foundation
High-dose Vitamin D3 without K2 can disrupt calcium metabolism. K2 MK-7 ensures calcium is directed correctly and works synergistically with D3 to support hormonal health. Most D3 supplements ignore this relationship entirely. Foundation doesn't.
What the Research Shows
Research shows Vitamin K2 directly influences testosterone-producing Leydig cells in the testes. Studies have also demonstrated that K2 supplementation supports testosterone levels in men, independent of its role as a D3 cofactor.
View the Human Study
Testosterone support and calcium metabolism in men, published clinical research
What to Expect
How it Works with Other Ingredients
Vitamin D3
K2 and D3 are inseparable partners. K2 activates the proteins that D3 produces, making both ingredients significantly more effective together.
Boron
Boron supports the metabolism of both K2 and D3, enhancing the hormonal signaling network both vitamins support.
Zinc
Zinc supports testosterone synthesis at the cellular level while K2 supports the testicular environment where that synthesis occurs.