AlgaeCal is the world's only clinically studied plant-based calcium supplement, and the only calcium proven to increase bone density in humans, not just slow its loss. Derived from a rare South American marine algae (Lithothamnion superpositum), AlgaeCal naturally contains calcium alongside magnesium, boron, and over 70 trace minerals in a whole-food matrix your body recognizes and absorbs more effectively than conventional rock-based calcium. Backed by three published human clinical studies and a landmark 7-year safety study, AlgaeCal offers a science-validated approach to lifelong bone health. Whether you're building bone density in your 30s or protecting it in your 60s, AlgaeCal delivers the foundational mineral support your skeleton demands naturally, safely, and effectively.