Which of the following is considered the active form of calcium?
Ionised calcium
Albumin bound calcium
Phosphate bound calcium
Protein bound calcium
In blood viually all of calcium is in the plasma, which has a mean normal calcium concentration of approximately 9.5mg/dl. calcium exists in 3 chemical states in plasma, of which 50% is Ionised , 40% is bound to proteins, 10% is complexed with small anions. The free or ionised calcium is the biologically active form . Its concentration in plasma is tightly regulated by vitamin D and parathyroid hormone. Teitz textbook of clinical biochemistry , 6th edition,section 5, page number 1736.
nutrition and digestion