1. 1. Order Your Tests

    Browse from hundreds of tests and select the ones you want.

  2. 2. Visit a Lab

    Visit a lab near you at your convenience; no appointment time necessary.

  3. 3. Get Your Results

    Physician-reviewed lab results are available online within 24-72 hours.

Calcium Blood Test

This Calcium Blood Test is used to measure levels of calcium in the body by way of an accurate blood test.

Order Test
Test Preparation:
Testing Method:
Blood draw

This Calcium Blood Test is used to measure levels of calcium in the body by way of an accurate blood test. Calcium is essential in keeping bones and teeth healthy and plays key roles in sending nerve signals and blood clotting. Calcium deficiencies (hypocalcemia) can cause bones to become brittle and can lead to osteoporosis, cramps, dermatitis, and skeletal malformations. Dairy products are rich in calcium and, barring an allergy or intolerance, it’s important to make sure they are part of your regular diet. With our Calcium Blood Test, you can know for sure if your diet has a healthy balance of this necessary mineral.

How Our Calcium Blood Test Works

For our Calcium Blood Test, simply place your order online and stop by one of our 4,000+ nationwide testing facilities at your convenience (no appointment required). A member of the center’s staff will collect a small blood sample at which point your part of the process is done. The sample collection itself takes only a few minutes and most patients are in, out and about their day in under a half-hour. From there, your sample will be processed in a CLIA-certified laboratory which will perform a total calcium test1 to assess how much calcium is in your blood, which is a good measure of whether you have enough calcium. You will get your results within 24 to 72 hours.

Common Calcium Deficiency Symptoms

Calcium deficiency2 can lead to osteoporosis, or thinning of the bones. It can also lead to rickets in children, although this is most commonly associated with vitamin D deficiency. In rickets, the growth cartilage does not correctly mineralize, leading to skeletal deformities.

However, the test is primarily looking for low blood calcium, which is often asymptomatic. Symptoms can vary widely, but include mouth numbness, tingling in the hands and feet, and muscle spasms. More serious symptoms can include renal injury, brain issues, cataracts, seizures, and congestive heart failure. These are extremely rare, however.

Low blood calcium can also be caused by vitamin D or magnesium deficiency or issues with your parathyroid glands.

Meanwhile, high blood calcium can cause symptoms such as constipation, nausea, abdominal pain, loss of appetite, frequent urination, increased thirst and confusion.

How to Interpret Your Results

We strive to make your results as easy to read as possible. When you get your results, it will have two columns. The first column, “Results,” is your actual blood calcium levels. There will be two marks here, one for total blood calcium and the other an estimate of ionized blood calcium. The second column, “Flag,” will show a mark if your levels are two low. The third column, “reference range” shows what is considered normal so you can see how far outside normal range you are.

A “Flag” will show that your blood calcium levels are either low or high.

Calcium Testing Versus Vitamin D Testing

While low blood calcium can indicate a vitamin D deficiency, this test will not actually confirm whether you have enough vitamin D. If you are concerned about your vitamin D levels, you should order a vitamin D test.

Note that it is very common for your physician to order tests of both if you have bone issues or issues absorbing calcium. Doing both tests together can also help you determine what you are actually deficient in.


  • You should take this test if you have osteomalacia (soft bones) or low bone density. If you have symptoms of either low or high blood calcium, you should also take this test.

    The test can also indicate vitamin D deficiency, but you should consider getting a vitamin D test (or both) if you suspect that or are not sure.

  • While we do our best to make your results clear, our care counselors are available to answer any of your questions. We can also put you in touch with a physician who can give medical advice, such as recommending supplements or suggesting you should talk to your family doctor.

  • The test is accurate, however, it does not tell you how much calcium is in your bones. If you are concerned about bone health, you should talk to a medical professional about a bone density scan.

  • If your calcium is too low then you should also check your vitamin D levels. Many people are deficient in vitamin D, and you may need to take a supplement. You should also get your magnesium levels checked. Tell your doctor your blood calcium is low. In most cases you should check again after taking a vitamin D and/or calcium supplement for a while. Your doctor may, however, want to check for more serious conditions.

  • High blood calcium can indicate a bone disorder or an issue with your parathyroid gland. It can also be the result of taking too much vitamin D. Because so many people are deficient, some people take unnecessarily large doses. However, you should talk to your doctor.

  1. https://medlineplus.gov/lab-tests/calcium-blood-test/

  2. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/