Calcium

Function

Calcium is one of the most vital minerals in the human body, playing a central role in several physiological processes beyond bone health. Roughly 99% of the body's calcium is stored in the teeth and bones, while the remaining 1% circulates in the blood. This circulating calcium is essential for muscle contraction, nerve signal transmission, blood coagulation, and the proper functioning of the heart.

Why it is Ordered

Calcium levels are typically measured as part of a Basic Metabolic Panel (BMP) or Comprehensive Metabolic Panel (CMP) during routine check-ups. It is also ordered to investigate symptoms of bone disease, kidney stones, neurological issues, or cardiac arrhythmias. Doctors use it to monitor patients with known parathyroid disorders, certain types of cancer, or those taking medications that affect mineral balance, such as diuretics or lithium.

Associated Conditions

Abnormal calcium levels are frequently linked to the parathyroid glands, which regulate calcium via Parathyroid Hormone (PTH).

• Hypercalcemia (High Calcium): Often caused by primary hyperparathyroidism or malignancies (bone metastasis). It can lead to 'moans, groans, stones, and bones'—psychiatric overtones, abdominal pain, kidney stones, and bone aches.
• Hypocalcemia (Low Calcium): Frequently caused by Vitamin D deficiency, hypoparathyroidism, or chronic kidney disease. It can lead to muscle cramps, tetany (uncontrolled muscle spasms), and tingling in the extremities.