Quick Facts
- Sample: Random urine specimen
- Fasting: Optional – avoid calcium supplements 24 hours before
- Turn-around: 2-4 business days. May take longer based on weather, holiday or lab delays.
Benefits
- Screen for kidney stone risk - Detect excessive calcium excretion before stones form
- Monitor calcium metabolism - Track how well your body processes calcium
- Convenient home collection - No 24-hour urine collection required
- Early detection of bone disorders - Identify potential parathyroid or bone issues
- Kidney function assessment - Evaluate how well kidneys regulate calcium
- Preventive health insights - Make informed decisions about diet and supplements
Who Is This Test For?
- History of kidney stones - Monitor calcium levels to prevent recurrence
- Bone health concerns - Screen for calcium metabolism disorders
- Family history of kidney stones - Proactive screening for genetic predisposition
- Suspected parathyroid disorders - Evaluate calcium regulation problems
- Chronic kidney disease monitoring - Track kidney function over time
- High calcium supplement users - Ensure safe supplementation levels
How It Works - Just 3 Steps
- Order online - Purchase your test kit and receive collection instructions
- Collect sample - Provide a random urine sample at home using sterile container
- Get results - Receive results in 2-4 business days
FAQ
What does this test measure? The ratio of calcium to creatinine in your urine, helping assess calcium excretion and kidney function.
Is this test as accurate as a 24-hour urine collection? While 24-hour collection is the gold standard, this random test effectively screens for calcium problems (Mayo Clinic 2024).
What if my results are abnormal? High ratios may indicate increased kidney stone risk; low ratios could suggest bone health issues requiring further evaluation.
Can medications affect my results? Yes - antacids, diuretics, steroids, and vitamin D supplements can increase calcium excretion (Quest Diagnostics).
How often should I test? Depends on your risk factors - annually for prevention, quarterly if monitoring treatment.
Do I need to fast for this test? No fasting required, but avoid calcium supplements and dairy 24 hours before testing for best accuracy.
More Details
What is the purpose of this test?
This test evaluates how much calcium your kidneys excrete by measuring the calcium-to-creatinine ratio in a random urine sample. Creatinine serves as a stable marker to account for urine concentration variations due to hydration levels (MedlinePlus 2024). The ratio helps detect hypercalciuria (excess calcium excretion), which increases kidney stone risk, or hypocalciuria, which may indicate bone metabolism problems.
Who would benefit from this test?
Individuals with recurrent kidney stones benefit most from this screening, as hypercalciuria is a common underlying cause. People with family histories of kidney stones, suspected parathyroid disorders, or bone diseases should consider testing. Those taking high-dose calcium supplements or vitamin D also benefit from monitoring to prevent complications (Quest Diagnostics).
When should I order this test?
Order this test if you've had kidney stones, experience symptoms like painful urination or blood in urine, or have unexplained bone pain. Consider testing if you have a family history of kidney stones, take calcium supplements regularly, or have been diagnosed with hyperparathyroidism. Proactive screening is valuable for those wanting to assess their calcium metabolism and kidney function as part of preventive healthcare.
How do I interpret the results?
Results show your calcium-to-creatinine ratio, typically reported in mg/g creatinine. Understanding your numbers helps assess kidney stone risk and calcium metabolism status.
Ratio < 0.14 mg/g
- What it means: Normal calcium excretion
- Typical action: Continue current lifestyle
Ratio 0.14–0.20 mg/g
- What it means: Borderline elevated
- Typical action: Monitor diet, increase fluids
Ratio > 0.20 mg/g
- What it means: Hypercalciuria (high risk)
- Typical action: Medical evaluation, 24-hour urine test
Ratio < 0.05 mg/g
- What it means: Very low excretion
- Typical action: Evaluate for bone disorders
Most kidney stones contain calcium, making early detection of hypercalciuria crucial for prevention.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation
Pre-test preparation
Avoid milk, dairy products, and calcium supplements 24 hours before testing for most accurate results. Inform your doctor about medications including antacids, diuretics, steroids, or vitamin D supplements, as these can affect calcium excretion (MyUpchar). Collect your random urine sample in the sterile container provided, preferably mid-stream for best quality.
How often should I get tested?
Testing frequency depends on your individual risk factors and health status. Regular monitoring helps track treatment effectiveness and prevent complications.
- Preventive screening: Every 1–2 years
- History of kidney stones: Every 6–12 months
- Active treatment monitoring: Every 3–6 months
- High-risk medication use: Every 6 months
- Parathyroid disorders: As directed by physician
Why early detection matters
Early identification of calcium excretion abnormalities prevents serious complications including recurrent kidney stones, bone loss, and kidney damage. Hypercalciuria affects up to 10% of the population and is present in 50% of kidney stone formers (PMC 2013). Detecting problems early allows for dietary modifications, medication adjustments, and lifestyle changes that effectively prevent stone formation and preserve kidney function.
Related tests you may consider
Calcium Urine Test, 24-Hour - Measures calcium levels in the urine over 24 hours to help screen for, diagnose, and monitor various conditions related to the bones, heart, nerves, kidneys, and teeth.
Calcium Serum Test- Checks the amount of calcium in your blood to help find problems with your bones, muscles, nerves, or kidneys and make sure your calcium levels stay healthy.
Parathyroid Hormone (PTH) Intact without Calcium Blood Test - Measures the level of PTH in the blood to help screen for osteoporosis and other underlying health conditions.
Vitamin D 25-Hydroxy Blood Test - Checks if you have enough vitamin D, helping to ensure your bones stay healthy and reducing the risk of various health issues associated with vitamin D deficiency.
Comprehensive Metabolic Panel (CMP-14) with eGFR Blood Test - Evaluates nutrient levels, liver, and kidney function.
