Calcium has various functions in the body: it is a determinant of the strength of the skeletal system, it is necessary for normal nerve and muscle function, it affects the activity of many enzymes and it also plays an important role in intracellular signaling. An average adult has 1-2 kg of calcium in his/her body, 98% is stored in the skeletal system.
Phosphorus is another important compound of the bones. It is an important factor in the body’s energy processes.
Vitamin D is also essential for bone metabolism, which helps in the absorption of calcium from the intestine, ensures the level of calcium in the blood, as well as mineralization and incorporation into the bone. It enhances the formation of the bone base and the synthesis of proteins involved in the process. In its absence, when it is insufficient to solidify the soft-bone base with minerals, we speak of osteomalacia (osteoporosis).
Bone metabolism is also regulated by hormones, one of the most important is the parathyroid hormone, which raises blood calcium levels to normal. The other key hormone is calcitonin, which is responsible for reducing the level of calcium in the blood to keep the balance and for the incorporation of calcium into the bone.
The composition and structure of bones adapts to the changing needs of a changing environment, forming and resorbing, depending on the strength and load of the musculoskeletal system. As the load increases, the bone stock builds, and as physical activity decreases, so does the mass and strength of the bones. 10% of healthy bone tissue is rebuilt every year.