Ostelin Cal-DK2 provides optimal delivery of calcium into the bones with a convenient 1-a-day dose. Cal-DK2 contains calcium, which helps reduce bone density loss in pregnant, post-menopausal and elderly women. It also contains high strength vitamin D3, which promotes calcium absorption. Vitamin K2 activates Osteocalcin, a protein that regulates calcium which is essential for bone mineralisation. A diet deficient in calcium can lead to osteoporosis in later life.