Vitamin K2
Also called: K2, MK-7
What it means
Vitamin K2 is a nutrient that helps direct calcium into your bones and away from your arteries by activating specific calcium-binding proteins.
Getting K2 along with calcium may help make sure the calcium you take in actually goes into building bone rather than settling in your blood vessels.
Vitamin K2 works like a traffic director for calcium in your body. It activates a protein called osteocalcin, which grabs calcium and binds it into your bone, and it also activates another protein that keeps calcium out of your arteries. Without enough K2, calcium can end up in soft tissues like blood vessels instead of your skeleton, which is not where you want it.
Good food sources include natto, hard cheeses like Gouda and Brie, egg yolks, and dark chicken meat. The MK-7 form of K2 is often preferred because it stays active in your body for about 72 hours, longer than other forms. A typical supplemental dose discussed is 100–200 mcg daily, taken as part of a broader nutrient plan.
K2 is usually considered alongside calcium, vitamin D3, and magnesium, since these nutrients work as a team — calcium provides the raw material, D3 helps you absorb it, K2 directs it into bone, and magnesium helps activate vitamin D. K2 is one piece of a bigger nutritional picture that also includes weight-bearing exercise, healthy hormones, sleep, and stress management when people talk about supporting bone health over time.
How sure is this?
Graded Strong Clinical Evidence: Supported by multiple well-designed clinical studies in humans. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Questions people ask about this
Calcium alone often isn't enough because bone building needs a whole team of nutrients working together, not just one mineral. If you're low on vitamin D, magnesium, vitamin K2, protein, or other supporting nutrients — or if a gut condition or certain medications are affecting absorption — the calcium you take may not actually be making it into your bones.
Read the full answer →Focus on getting enough calcium, vitamin D, vitamin K2, protein, and magnesium from a balanced, whole-food diet — these are the raw materials your bones need to rebuild themselves. Calcium (1,000–1,200 mg/day) is the main mineral, vitamin D helps you absorb it, K2 helps direct it into bone rather than soft tissue, and protein and magnesium support the collagen and mineral structure of bone.
Read the full answer →The best-supported ones for bone health are calcium, vitamin D3, vitamin K2, and magnesium — these four work together and have solid research behind them. Collagen peptides, vitamin C, adequate protein, and omega-3 fatty acids also show promising evidence, though some of that research is newer and still developing. The real "hype" risk isn't a specific supplement being fake, but taking things randomly, in the wrong amounts, or without knowing your actual blood levels and food intake first.
Read the full answer →Not in the same way you did while building. Bone is living tissue that adapts to the demands you place on it, so once you've reached your goals, you generally need less intensity than during the building phase — but you do need to keep giving your skeleton some ongoing signal to preserve what you gained. How that looks long-term is personal to you.
Read the full answer →Your plan has three layers: daily habits, weekly habits, and periodic check-ins. Daily, you support your bones with nutrition, movement, and sleep; weekly, you build a rhythm around your OsteoStrong session, resistance training, recovery, and a quick nutrition review; and every few months to a couple of years, you check in with your healthcare provider on labs and a DEXA scan. The real key isn't perfection — it's staying consistent over the long haul.
Read the full answer →Related words
Calcium is the main building-block mineral in bone, and since your body can't make it, you need to get it from food…
Vitamin D is a nutrient that helps your gut absorb calcium so it can be used to build and maintain bone.
Magnesium is a mineral that helps activate vitamin D and forms part of the actual crystal structure of bone.
Osteocalcin is a hormone made by bone that helps regulate blood sugar, muscle energy use, and other body functions…
Bone mineral density (BMD) measures how much mineral is packed into your bones, usually estimated with a DEXA scan,…
Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
