NBRC Normal Values TMC Practice Test

Calcium status in the blood is normally defined by a relatively narrow window. The accepted normal range for total serum calcium is about 8.5–10.5 mg/dL. This range reflects the combined amount of calcium bound to proteins and the free ionized portion that’s biologically active.

Among the given choices, the range 8.5–10.5 mg/dL best fits that standard. Values starting lower than roughly 8.5 mg/dL would be considered low (hypocalcemia), while those extending well above 10.5 mg/dL would be high (hypercalcemia). Remember that total calcium can be influenced by albumin levels; a low albumin can make total calcium appear low even if the ionized calcium is normal, which is why sometimes corrected or ionized calcium measurements are used.