This bone-support formula combines 400mg of **Calcium**, 1,000 IU of **Vitamin D3**, and 130mcg of **Vitamin K** — three nutrients all dosed within their clinical ranges and chosen to work as a unit rather than in isolation. The calcium uses a di-calcium malate form that absorbs well and doesn't require food, and at 400mg per serving it stays under the ~500mg-per-dose point where calcium absorption starts to drop off.

What makes this more useful than calcium on its own is how the three fit together: the Vitamin D3 helps your body actually absorb the calcium (without it you take in only 10-15%), and vitamin K's **K2** form directs that calcium into your bones and teeth instead of your arteries. That K2 routing matters — it partly addresses the cardiovascular concern that's been raised about isolated calcium supplements. One caveat on the K: of the 130mcg total, only 30mcg is the long-acting MK-7 form doing that bone-routing work, with the rest being K1 for clotting. Most bone studies use 90-180mcg of MK-7, so this sits on the lighter side for that specific job.

Two things to keep in mind. Your total calcium should land around 1,000-1,200mg a day from all sources, so if you already eat dairy or leafy greens, one serving covers the gap — the label's up-to-3-servings range can push you past what you need. And if you take a blood thinner like warfarin, the vitamin K here can interfere, so check with your doctor first.