NOW Foods Coral Calcium 1000 mg provides calcium sourced from fossilized above-sea coral (Lithothamnion sp.) — a naturally mineralized marine plant that provides calcium alongside naturally co-occurring magnesium and over 70 trace minerals in proportions similar to the mineral ratios found in human bone. Unlike calcium carbonate from limestone or oyster shell, coral calcium comes with a full complement of trace minerals that play supporting roles in bone metabolism, making it a more nutritionally complex calcium source. Each capsule provides 1,000 mg of coral calcium contributing a meaningful elemental calcium dose for daily bone health support. NOW Foods uses above-sea fossilized coral — not live coral — preserving marine ecosystems. Manufactured in their GMP-certified facility with identity verification and potency testing.