Calcium is an essential mineral involved in bone strength, muscle contraction, nerve signaling, and blood clotting.

Blood calcium exists in two forms: bound (to proteins like albumin) and free/ionized (biologically active).

Clinical uses include:

Diagnosing calcium metabolism disorders.

Evaluating parathyroid gland function.

Monitoring patients with kidney disease, bone disorders, or certain cancers.

Investigating symptoms such as muscle spasms, tingling, weakness, or confusion.

The test is performed using a blood sample.

Analyte: Serum calcium concentration.

Normal Range: ~8.5 – 10.5 mg/dL (varies slightly by lab).

Abnormal Findings:

High calcium (hypercalcemia): May indicate hyperparathyroidism, malignancy, vitamin D excess, or prolonged immobilization.

Low calcium (hypocalcemia): May indicate hypoparathyroidism, vitamin D deficiency, kidney disease, or malnutrition.

Clinical Use:

Provides insight into bone and mineral metabolism.

Helps differentiate endocrine vs. renal causes of abnormal calcium levels.

Guides treatment in metabolic bone disease, renal disorders, and critical care.