What types of calcium make up the total calcium level?

Total calcium levels in the body consist of three main forms: ionized calcium, which is the biologically active form; bound calcium, which is attached to proteins like albumin; and complexed calcium, which is bound to anions such as citrate or phosphate. Ionized calcium typically accounts for about 50% of total calcium, while the other forms contribute to the remaining percentage. Monitoring these forms is essential for assessing calcium homeostasis and diagnosing related disorders.