Did you know that most calcium carbonate supplements come from limestone rock and lack other bone-supportive nutrients? New Chapter's organic plant calcium supplement for bone health is different! Bone Strength Take Care is sourced from Red Marine Algae thats rich in Calcium plus naturally occurring Magnesium and 70+ trace minerals. This plant calcium from Iceland has been researched by international experts in orthopedics, sports medicine, and physiology. For your best absorbed calcium formula, contains Vitamins K2 and D3 that directs calcium right to your bones where you need it, which also helps to maintain artery health. Experience 3-in-1 benefits: strong bones and teeth, flexible joints, and heart health.