Bone is made primarily of minerals (mainly calcium and phosphorus) and proteins (mainly collagen and osteocalcin). In addition to providing architectural support for the body and protective armor for delicate organs such as the brain and heart, many bones also contain marrow, which is where new blood cells are created.
Vitamin D is vital to bone health because it is required both to maximize absorption of calcium from food in the intestines, and to synthesize osteocalcin. Vitamin K2 (a form of Vitamin K that only naturally exists in animal foods), is also required for proper function of osteocalcin and certain other bone proteins.
Bone is a dynamic, living tissue that is constantly remodeling itself. Bone cells listen to growth hormone, thyroid hormone, insulin, estrogen, and testosterone, to know when to grow.
Bone is also the body’s calcium warehouse. Calcium is critical to every cell in the body, so there must be some circulating in the blood at all times. If blood calcium drops, parathyroid hormone (made by the parathyroid glands) can command bone to release some of its calcium into the blood to keep the blood calcium levels normal.
Conditions affecting bone include: Osteoporosis, Paget’s disease, Rickets, and Osteomalacia.