Which of the following is a mineral electrolyte commonly measured in clinical chemistry?

• A. Calcium
• B. CK
• C. LD
• D. Alkaline phosphatase

Answer: (A)

Mineral electrolytes are charged ions in body fluids, and calcium is one of the most important of these. Calcium exists mainly as Ca2+ in serum and is essential for bone formation, muscle contraction, nerve signaling, and blood clotting. Because of its widespread and critical roles, calcium is routinely measured in clinical chemistry as part of routine metabolic panels, sometimes distinguishing total calcium from the physiologically active ionized form.

The other options are not minerals or electrolytes; they are enzymes (creatine kinase, lactate dehydrogenase, alkaline phosphatase) that serve as markers of tissue injury or disease rather than a basic electrolyte. So calcium stands out as the mineral electrolyte commonly measured.