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

The 24-hour urine test provides an accurate measure of calcium excretion compared to a random urine sample.

Clinical uses include:

Diagnosing hypercalciuria (excess calcium in urine), which can lead to kidney stones.

Evaluating parathyroid gland disorders (hyperparathyroidism, hypoparathyroidism).

Monitoring patients with osteoporosis, kidney disease, or metabolic bone disorders.

Assessing dietary calcium intake and excretion balance.

The test requires collecting all urine passed in 24 hours in a special container.

Analyte: Calcium concentration in 24-hour urine.

Normal Range: Approximately 100–300 mg/24 hrs (varies by lab, age, and diet).

High Calcium Excretion: May indicate hyperparathyroidism, excessive dietary intake, vitamin D excess, or kidney stone risk.

Low Calcium Excretion: May suggest hypoparathyroidism, malabsorption, vitamin D deficiency, or chronic kidney disease.

Clinical Use:

Detects abnormalities in calcium metabolism.

Differentiates renal vs non-renal causes of calcium imbalance.

Supports diagnosis of bone, endocrine, and renal disorders.