Vitamin K2 (MK-7)
A long-chain vitamin K2 form used in supplements. It is discussed most often for calcium-handling proteins tied to bone and soft-tissue calcification biology.
Plain English
MK-7 is the longer-lasting K2 form in many D3 plus K2 products.
Why It Matters After 40
It is useful only inside the bigger bone-health system: resistance training, protein, vitamin D status, calcium sufficiency, and medication context.
What To Do With It
Avoid changing vitamin K intake if you use warfarin unless your clinician or pharmacist guides it.
Proof Structure
Vitamin K activates key proteins
NIH ODS describes vitamin K as needed for proteins involved in blood clotting and bone metabolism.
Source: NIH ODS vitamin K