Calcium
A blood test that measures calcium levels to assess bone health, parathyroid function, and detect mineral imbalances that may indicate various medical conditions.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
This test measures the total amount of calcium circulating in the blood. Calcium is the most plentiful mineral in the human body, with approximately 99% residing in bones and teeth and the remaining 1% distributed in the bloodstream, where it performs functions that are critical enough to warrant tight hormonal regulation.
Beyond building the skeleton, that small circulating fraction of calcium is essential for nerve signal transmission, muscle contraction (including the heartbeat), blood clotting, and enzyme activation. Because so many vital processes depend on stable blood calcium, the body employs a precise feedback loop: when calcium levels dip, the parathyroid glands release parathyroid hormone (PTH), which raises calcium by boosting absorption in the gut and kidneys and, if necessary, drawing calcium out of bone. When levels rise, PTH secretion drops, and excess calcium is excreted. This test captures a snapshot of where calcium sits within that tightly controlled range.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing symptoms that may be associated with calcium imbalances, such as fatigue, muscle weakness, or irregular heartbeat
- Those with a personal or family history of kidney stones, osteoporosis, or parathyroid disorders
- Individuals with conditions that may affect calcium levels, including kidney disease, certain cancers, or malabsorption disorders
- People taking medications that can impact calcium metabolism, such as certain diuretics, lithium, or calcium supplements
- Those undergoing routine health screening or monitoring for chronic conditions that may affect mineral balance
What to expect
Preparation
No special preparation is typically needed. Fasting may be required in some cases; follow your healthcare provider's instructions. Inform your doctor about any medications or supplements you're taking. Some medications and supplements can affect calcium levels, so individuals should provide a complete list of all medications and supplements to their healthcare provider.
Sample Type
A needle is used to draw blood from a vein in the arm or hand. The blood collection is a standard procedure that takes only a few minutes.
Collection
A healthcare provider will clean a small area of the arm with an antiseptic. A tourniquet is placed around the upper arm to fill veins with blood. A needle is inserted into a vein to draw blood into a vial or syringe. The sample is sent to a laboratory for analysis.
Turnaround
Results are typically available within 1 day from the date of specimen pickup. The turnaround time may vary depending on the laboratory and testing schedule.
Understanding your results
Normal blood calcium for adults typically falls between 8.5 and 10.2 mg/dL, though exact reference ranges differ from lab to lab, so results should always be compared to the range printed on the same report. A value outside the expected range does not necessarily indicate disease on its own; healthcare providers interpret calcium results alongside other factors including albumin levels (since calcium binds to this protein), PTH, vitamin D, kidney function, medications, and the individual's symptoms and medical history.
| Population | Reference Range | Notes |
|---|---|---|
| Adults | 8.5-10.2 mg/dL | Normal range may vary slightly between laboratories |
| Adults (Alternative Range) | 8.6-10.3 mg/dL | Some laboratories use this slightly different range |
Reference ranges shown are general guidelines. Your lab report will include the specific reference range used by the laboratory that processed your sample, which is the authoritative range for interpreting your results.
What does a “Low” result mean?
Hypocalcemia is defined as a total serum calcium concentration less than 8.8 mg/dL. Hypocalcemia, also known as low calcium levels or calcium deficiency disease, happens when you do not have enough calcium in your blood. Many different health conditions can cause hypocalcemia, and it's often caused by abnormal levels of parathyroid hormone (PTH) or vitamin D in your body. Many factors can cause or contribute to hypocalcemia, including aging-related changes, genetic disorders, health conditions such as pancreatitis, kidney disorders, medications that affect calcium absorption, not getting enough calcium or Vitamin D in your diet, and parathyroid disorders. Too little calcium can cause muscle spasms, numbness, confusion or seizures.
What does a “High” result mean?
The following blood calcium levels indicate different levels of diagnosis and severity of hypercalcemia: Mild hypercalcemia: 10.5 to 11.9 mg/dL, Moderate hypercalcemia: 12.0 to 13.9 mg/dL, Hypercalcemic crisis: 14.0 to 16.0 mg/dL. The most common cause of high calcium blood level is excess PTH released by the parathyroid glands due to an enlargement of one or more parathyroid glands or a growth on one of the glands. Most of the time, these growths are benign. Other causes may include certain kinds of cancers, such as lung and breast cancer, or cancer that has spread to organs. Too much calcium in the blood can cause tiredness, weakness, constipation and nausea.
Privacy & confidentiality
All test orders are authorized and results reviewed by an independent, board-certified physician who is not the patient's personal doctor. At LevelPanel, we prioritize your privacy and understand that many individuals prefer to keep their health information confidential. When you order a calcium test through our platform, your results are <u>not reported to your doctor</u> unless you specifically choose to share them. The test results are <u>not part of your medical records</u> and will <u>not appear on insurance statements</u> since you pay directly for the service. Your calcium test results are delivered securely through our HIPAA-compliant patient portal, ensuring that only you have access to your health information. We do not share your results with employers, insurance companies, or government databases. This confidential testing approach allows individuals to monitor their bone health and mineral balance privately, whether they're concerned about potential calcium imbalances, tracking the effectiveness of dietary changes, or simply want baseline health information without involving their healthcare provider initially. Many people choose private lab testing for calcium levels when they want to monitor their health discreetly, especially if they have concerns about bone health, kidney function, or parathyroid disorders but prefer to understand their status before involving their regular healthcare provider. With no doctor visit required and complete confidentiality, you can take control of your health monitoring on your own terms.
Frequently asked questions
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Last reviewed: April 2026
CPT Code: 82310
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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