Parathyroid Diseases (PTH)

Parathyroid Disease (PTH) Lab Tests and health information

Do you have a family history of parathyroid disease? 

Our pth test can detect early parathyroid hormone abnormalities and low or high calcium levels in the blood.

The parathyroid glands, which are four little glands in your neck, are affected by the parathyroid disease, which is an endocrine disorder. Hormones produced by these glands assist in regulating the amount of calcium and phosphorus in your blood.

Hyperparathyroidism develops when one or more of these glands become hyperactive (HPT). If not treated appropriately, this illness might lead to significant health complications. HPT can lead to kidney stones and osteoporosis if left untreated. 

When one or more of these parathyroid glands become inactive, hypoparathyroidism occurs. Symptoms include weariness, sadness, and physical weakness, which might result from this. A high blood pressure level is the most prevalent sign. Some patients, however, might have hypocalcemia without having high blood pressure. 

Click here for more information about parathyroid disease and lab tests to detect, diagnose and monitor.

If you have a family history of hyperparathyroidism or hypoparathyroidism, it's important to know if you're at risk. We provide lab testing to help you measure and evaluate your biomarkers to get the information you need to obtain the treatment you require before any illness occurs. 

You should be aware that there are effective treatments available for these conditions! Getting tested for it with our lab tests today is the first step toward a treatment! We provide many test choices so that you can get exactly what you need to detect this disease before it progresses. Our lab tests can help identify parathyroid disease early by measuring calcium levels in your blood. This is especially significant for persons with a family history of PTH problems since they are more likely to develop them. Early diagnosis means earlier management and better results for people with this illness. 

Order any time of the day or night and get results in 24 to 48 hours for most tests from Quest Diagnostics labs.  Results are private and secure, and a physician reviews them. Dynamic charting lets you keep track of changes over time if you need to. Friendly customer service is always available by phone or chat if you have any questions about ordering a test or getting the results back from the lab.

Take control of your health by ordering your blood tests for Parathyroid Diseases (PTH) tests from the list below.


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Description: A Calcium test is a blood test that is used to screen for, diagnose, and monitor a wide range of medical conditions.

Also Known As: Ca Test, Serum Calcium Test, Calcium Blood Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Calcium test ordered?

A blood calcium test is frequently requested during a general medical evaluation. It's usually part of the comprehensive metabolic panel or the basic metabolic panel, two sets of tests that can be done during an initial evaluation or as part of a routine medical checks.

Many people do not experience symptoms of high or low calcium until their levels are dangerously high or low.

When a person has certain types of cancer, kidney illness, or has had a kidney transplant, calcium monitoring may be required. When someone is being treated for abnormal calcium levels, monitoring may be required to determine the effectiveness of medications such as calcium or vitamin D supplements.

What does a Calcium blood test check for?

Calcium is one of the most plentiful and vital minerals in the human body. It is required for cell signaling as well as the proper operation of muscles, nerves, and the heart. Calcium is essential for blood clotting as well as bone growth, density, and maintenance. This test determines how much calcium is present in the blood.

Calcium is found complexed in the bones for 99 percent of the time, while the remaining 1% circulates in the blood. Calcium levels are closely monitored; if too little is absorbed or consumed, or if too much is lost through the kidney or stomach, calcium is removed from bone to keep blood concentrations stable. Approximately half of the calcium in the blood is metabolically active and "free." The other half is "bound" to albumin, with a minor proportion complexed to anions like phosphate, and both of these forms are metabolically inactive.

Blood calcium can be measured using two different tests. The free and bound forms of calcium are measured in the total calcium test. Only the free, physiologically active form of calcium is measured in the ionized calcium test.

Lab tests often ordered with a Calcium test:

  • Phosphorus
  • Vitamin D
  • Magnesium
  • PTH
  • Albumin
  • Basic Metabolic Panel (BMP)
  • Comprehensive Metabolic Panel (CMP)

Conditions where a Calcium test is recommended:

  • Kidney Disease
  • Thyroid Disease
  • Alcoholism
  • Malnutrition
  • Parathyroid Diseases
  • Breast Cancer
  • Multiple Myeloma

How does my health care provider use a Calcium test?

A blood calcium test is used to screen for, diagnose, and monitor a variety of bone, heart, nerve, kidney, and tooth disorders. If a person has signs of a parathyroid disease, malabsorption, or an overactive thyroid, the test may be ordered.

A total calcium level is frequently checked as part of a standard health check. It's part of the comprehensive metabolic panel and the basic metabolic panel, which are both collections of tests used to diagnose or monitor a range of ailments.

When a total calcium result is abnormal, it is interpreted as a sign of an underlying disease. Additional tests to assess ionized calcium, urine calcium, phosphorus, magnesium, vitamin D, parathyroid hormone, and PTH-related peptide are frequently performed to assist determine the underlying problem. PTH and vitamin D are in charge of keeping calcium levels in the blood within a narrow range of values.

Measuring calcium and PTH combined can assist identify whether the parathyroid glands are functioning normally if the calcium is abnormal. Testing for vitamin D, phosphorus, and/or magnesium can assist evaluate whether the kidneys are excreting the right amount of calcium, and measuring urine calcium can help detect whether additional deficits or excesses exist. The balance of these many compounds is frequently just as critical as their concentrations.

The total calcium test is the most common test used to determine calcium status. Because the balance between free and bound calcium is usually constant and predictable, it is a reliable reflection of the quantity of free calcium present in the blood in most cases. However, the balance between bound and free calcium is altered in some persons, and total calcium is not a good indicator of calcium status. Ionized calcium measurement may be required in certain cases. Critically sick patients, those receiving blood transfusions or intravenous fluids, patients undergoing major surgery, and persons with blood protein disorders such low albumin are all candidates for ionized calcium testing.

What do my Calcium test results mean?

The amount of calcium circulating in the blood is not the same as the amount of calcium in the bones.

A feedback loop including PTH and vitamin D regulates and stabilizes calcium uptake, utilization, and excretion. Conditions and disorders that disturb calcium control can induce abnormal acute or chronic calcium elevations or declines, resulting in hypercalcemia or hypocalcemia symptoms.

Total calcium is usually tested instead of ionized calcium since it is easier to do and requires no additional treatment of the blood sample. Because the free and bound forms of calcium make up about half of the total, total calcium is usually a decent depiction of free calcium. Because nearly half of the calcium in blood is bonded to protein, high or low protein levels might alter total calcium test findings. In these circumstances, an ionized calcium test is more appropriate for measuring free calcium.

A normal total or ionized calcium test, when combined with other normal laboratory findings, indicates that a person's calcium metabolism is normal and blood levels are properly managed.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


Urinary calcium reflects dietary intake, rate of calcium absorption by the intestine and bone resorption. Urinary calcium is used primarily to evaluate parathyroid function and the effects of vitamin D. A significant number of patients with primary hyperparathyroidism will have elevated urinary calcium. However, there are other clinical entities that may be associated with increased urine calcium: Sarcoidosis, Paget's disease of bone, vitamin D intoxication, hyperthyroidism and glucocorticoid excess. Decreased urine calcium is seen with thiazide diuretics, vitamin D deficiency and familial hypocalciuric hypercalcemia.


Urinary calcium reflects dietary intake, rate of calcium absorption by the intestine and bone resorption. Urinary calcium is used primarily to evaluate parathyroid function and the effects of vitamin D. A significant number of patients with primary hyperparathyroidism will have elevated urinary calcium. However, there are other clinical entities that may be associated with increased urine calcium: Sarcoidosis, Paget's disease of bone, vitamin D intoxication, hyperthyroidism and glucocorticoid excess. Decreased urine calcium is seen with thiazide diuretics, vitamin D deficiency and familial hypocalciuric hypercalcemia.

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Description: An ionized calcium test is a blood test that is used to screen for, diagnose, and monitor a wide range of medical conditions.

Also Known As: Ionized Ca Test, Serum Ionized Calcium Test, Calcium Blood Test, Calcium Ionized Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is an Ionized Calcium test ordered?

A blood calcium test is frequently requested during a general medical evaluation. It's usually part of the comprehensive metabolic panel or the basic metabolic panel, two sets of tests that can be done during an initial evaluation or as part of a routine medical checks.

Many people do not experience symptoms of high or low calcium until their levels are dangerously high or low.

When someone develops numbness around the mouth, hands, and feet, as well as muscle spasms in those areas, an ionized calcium test may be ordered. Low ionized calcium levels can cause these symptoms. When calcium levels fall slowly, however, many people have no symptoms.

What does an Ionized Calcium blood test check for?

Calcium is one of the most plentiful and vital minerals in the human body. It is required for cell signaling as well as the proper operation of muscles, nerves, and the heart. Calcium is essential for blood clotting as well as bone growth, density, and maintenance. This test determines how much calcium is present in the blood.

Calcium is found complexed in the bones for 99 percent of the time, while the remaining 1% circulates in the blood. Calcium levels are closely monitored; if too little is absorbed or consumed, or if too much is lost through the kidney or stomach, calcium is removed from bone to keep blood concentrations stable. Approximately half of the calcium in the blood is metabolically active and "free." The other half is "bound" to albumin, with a minor proportion complexed to anions like phosphate, and both of these forms are metabolically inactive.

Blood calcium can be measured using two different tests. The free and bound forms of calcium are measured in the total calcium test. Only the free, physiologically active form of calcium is measured in the ionized calcium test.

Lab tests often ordered with an Ionized Calcium test:

  • Phosphorus
  • Vitamin D
  • Magnesium
  • PTH
  • Magnesium
  • Albumin
  • Basic Metabolic Panel (BMP)
  • Comprehensive Metabolic Panel (CMP)

Conditions where an Ionized Calcium test is recommended:

  • Kidney Disease
  • Thyroid Disease
  • Alcoholism
  • Malnutrition
  • Parathyroid Diseases
  • Breast Cancer
  • Multiple Myeloma

How does my health care provider use an Ionized Calcium test?

A blood calcium test is used to screen for, diagnose, and monitor a variety of bone, heart, nerve, kidney, and tooth disorders. If a person has signs of a parathyroid disease, malabsorption, or an overactive thyroid, the test may be ordered.

A total calcium level is frequently checked as part of a standard health check. It's part of the comprehensive metabolic panel and the basic metabolic panel, which are both collections of tests used to diagnose or monitor a range of ailments.

When a total calcium result is abnormal, it is interpreted as a sign of an underlying disease. Additional tests to assess ionized calcium, urine calcium, phosphorus, magnesium, vitamin D, parathyroid hormone, and PTH-related peptide are frequently performed to assist determine the underlying problem. PTH and vitamin D are in charge of keeping calcium levels in the blood within a narrow range of values.

Measuring calcium and PTH combined can assist identify whether the parathyroid glands are functioning normally if the calcium is abnormal. Testing for vitamin D, phosphorus, and/or magnesium can assist evaluate whether the kidneys are excreting the right amount of calcium, and measuring urine calcium can help detect whether additional deficits or excesses exist. The balance of these many compounds is frequently just as critical as their concentrations.

The total calcium test is the most common test used to determine calcium status. Because the balance between free and bound calcium is usually constant and predictable, it is a reliable reflection of the quantity of free calcium present in the blood in most cases. However, the balance between bound and free calcium is altered in some persons, and total calcium is not a good indicator of calcium status. Ionized calcium measurement may be required in certain cases. Critically sick patients, those receiving blood transfusions or intravenous fluids, patients undergoing major surgery, and persons with blood protein disorders such low albumin are all candidates for ionized calcium testing.

What do my Ionized Calcium test results mean?

The amount of calcium circulating in the blood is not the same as the amount of calcium in the bones.

A feedback loop including PTH and vitamin D regulates and stabilizes calcium uptake, utilization, and excretion. Conditions and disorders that disturb calcium control can induce abnormal acute or chronic calcium elevations or declines, resulting in hypercalcemia or hypocalcemia symptoms.

Total calcium is usually tested instead of ionized calcium since it is easier to do and requires no additional treatment of the blood sample. Because the free and bound forms of calcium make up about half of the total, total calcium is usually a decent depiction of free calcium. Because nearly half of the calcium in blood is bonded to protein, high or low protein levels might alter total calcium test findings. In these circumstances, an ionized calcium test is more appropriate for measuring free calcium.

A normal total or ionized calcium test, when combined with other normal laboratory findings, indicates that a person's calcium metabolism is normal and blood levels are properly managed.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


Description: A Vitamin D test is a blood test used to determine if you have a Vitamin D deficiency and to monitor Vitamin D levels if you are on supplementation.

Also Known As: Ergocalciferol Test, Vitamin D2 Test, Cholecalciferol Test, Vitamin D3 Test, Calcidiol Test, 25-hydroxyvitamin D Test, Calcifidiol Test, 25-hydroxy-vitamin D Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting preferred, but not required.

When is a Vitamin D test ordered:

When calcium levels are inadequate and/or a person exhibits symptoms of vitamin D deficiency, such as rickets in children and bone weakening, softness, or fracture in adults, 25-hydroxyvitamin D is frequently ordered to rule out a vitamin D deficit.

When a person is suspected of having a vitamin D deficiency, the test may be requested. Vitamin D deficiency is more common in older folks, people who are institutionalized or homebound and/or have minimal sun exposure, people who are obese, have had gastric bypass surgery, and/or have fat malabsorption. People with darker skin and breastfed babies are also included in this category.

Before starting osteoporosis medication, 25-hydroxyvitamin D is frequently requested.

What does a Vitamin D blood test check for?

Vitamin D is a group of chemicals that are necessary for the healthy development and growth of teeth and bones. The level of vitamin D in the blood is determined by this test.

Vitamin D is tested in the blood in two forms: 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. The primary form of vitamin D found in the blood is 25-hydroxyvitamin D, which is a relatively inactive precursor to the active hormone 1,25-dihydroxyvitamin D. 25-hydroxyvitamin D is routinely evaluated to assess and monitor vitamin D status in humans due to its longer half-life and higher concentration.

Endogenous vitamin D is created in the skin when exposed to sunshine, whereas exogenous vitamin D is taken through foods and supplements. Vitamin D2 and vitamin D3 have somewhat different molecular structures. Fortified foods, as well as most vitamin preparations and supplements, include the D2 form. The type of vitamin D3 produced by the body is also used in some supplements. When the liver and kidneys convert vitamin D2 and D3 into the active form, 1,25-dihydroxyvitamin D, they are equally effective.

Some tests may not differentiate between the D2 and D3 forms of vitamin D and just report the total result. Newer methods, on the other hand, may record D2 and D3 levels separately and then sum them up to get a total level.

Vitamin D's major function is to assist balance calcium, phosphorus, and magnesium levels in the blood. Vitamin D is necessary for bone growth and health; without it, bones become fragile, misshapen, and unable to mend themselves properly, leading to disorders such as rickets in children and osteomalacia in adults. Vitamin D has also been proven to influence the growth and differentiation of a variety of other tissues, as well as to aid in immune system regulation. Other illnesses, such as autoimmune and cancer, have been linked to vitamin D's other roles.

According to the Centers for Disease Control and Prevention, two-thirds of the US population has adequate vitamin D, while one-quarter is at risk of inadequate vitamin D and 8% is at risk of insufficiency, as defined by the Institute of Medicine's Dietary Reference Intake.

The elderly or obese, persons who don't receive enough sun exposure, people with darker skin, and people who take certain drugs for lengthy periods of time are all at risk of insufficiency. Adequate sun exposure is usually defined as two intervals of 5-20 minutes each week. Vitamin D can be obtained through dietary sources or supplements by people who do not get enough sun exposure.

This test has 3 Biomarkers

  • Vitamin D Total which is a combined measurement of Vitamin D, 25-Oh, D2 and Vitamin 25-Oh, D3
  • Vitamin D, 25-Oh, D2 which is a measurement of ergocalciferol Vitamin D, which is Vitamin D obtained through plant sources. 
  • Vitamin D, 25-Oh, D3 which is a measurement of cholecalciferol Vitamin D, which is Vitamin D obtained through animal sources.

Lab tests often ordered with a Vitamin D test:

  • Complete Blood Count
  • CMP
  • Iron and TIBC
  • Calcium
  • Phosphorus
  • PTH
  • Magnesium

Conditions where a Vitamin D test is recommended:

  • Kidney Disease
  • Osteoporosis
  • Lymphoma
  • Cystic Fibrosis
  • Autoimmune Disorders
  • Celiac Disease
  • Malabsorption
  • Malnutrition

Commonly Asked Questions:

How does my health care provider use a Vitamin D test?

Determine whether a deficit or excess of vitamin D is causing bone weakening, deformity, or improper calcium metabolism.

Because PTH is required for vitamin D activation, it can aid in diagnosing or monitoring problems with parathyroid gland function.

Because vitamin D is a fat-soluble vitamin that is absorbed from the intestine like a fat, it can help monitor the health of people with conditions that interfere with fat absorption, such as cystic fibrosis and Crohn's disease.

People who have had gastric bypass surgery and may not be able to absorb adequate vitamin D should be closely monitored.

When vitamin D, calcium, phosphorus, and/or magnesium supplementation is suggested, it can help assess the success of the treatment.

What do my Vitamin D results result mean?

Despite the fact that vitamin D techniques differ, most laboratories use the same reference intervals. Because toxicity is uncommon, researchers have focused on the lower limit and what cut-off for total 25-hydroxyvitamin D shortage implies.

A low blood level of 25-hydroxyvitamin D could indicate that a person isn't getting enough sunlight or dietary vitamin D to meet his or her body's needs, or that there's an issue with absorption from the intestines. Seizure medications, notably phenytoin, might occasionally interfere with the liver's generation of 25-hydroxyvitamin D.

Vitamin D insufficiency has been linked to an increased risk of some malignancies, immunological illnesses, and cardiovascular disease.

Excessive supplementation with vitamin pills or other nutritional supplements frequently results in a high level of 25-hydroxyvitamin D.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


Description: A Comprehensive Metabolic Panel or CMP is a blood test that is a combination of a Basic Metabolic Panel, a Liver Panel, and electrolyte panel, and is used to screen for, diagnose, and monitor a variety of conditions and diseases such as liver disease, diabetes, and kidney disease. 

Also Known As: CMP, Chem, Chem-14, Chem-12, Chem-21, Chemistry Panel, Chem Panel, Chem Screen, Chemistry Screen, SMA 12, SMA 20, SMA 21, SMAC, Chem test

Collection Method: 

Blood Draw 

Specimen Type: 

Serum 

Test Preparation: 

9-12 hours fasting is preferred. 

When is a Comprehensive Metabolic Panel test ordered:  

A CMP is frequently requested as part of a lab test for a medical evaluation or yearly physical. A CMP test consists of many different tests that give healthcare providers a range of information about your health, including liver and kidney function, electrolyte balance, and blood sugar levels. To confirm or rule out a suspected diagnosis, abnormal test results are frequently followed up with other tests that provide a more in depth or targeted analysis of key areas that need investigating. 

What does a Comprehensive Metabolic Panel blood test check for? 

The complete metabolic panel (CMP) is a set of 20 tests that provides critical information to a healthcare professional about a person's current metabolic status, check for liver or kidney disease, electrolyte and acid/base balance, and blood glucose and blood protein levels. Abnormal results, particularly when they are combined, can suggest a problem that needs to be addressed. 

The following tests are included in the CMP: 

  • Albumin: this is a measure of Albumin levels in your blood. Albumin is a protein made by the liver that is responsible for many vital roles including transporting nutrients throughout the body and preventing fluid from leaking out of blood vessels. 

  • Albumin/Globulin Ratio: this is a ratio between your total Albumin and Globulin  

  • Alkaline Phosphatase: this is a measure of Alkaline phosphatase or ALP in your blood. Alkaline phosphatase is a protein found in all body tissues, however the ALP found in blood comes from the liver and bones. Elevated levels are often associated with liver damage, gallbladder disease, or bone disorder. 

  • Alt: this is a measure of Alanine transaminase or ALT in your blood. Alanine Aminotransferase is an enzyme found in the highest amounts in the liver with small amounts in the heart and muscles. Elevated levels are often associated with liver damage. 

  • AST: this is a measure of Aspartate Aminotransferase or AST. Aspartate Aminotransferase is an enzyme found mostly in the heart and liver, with smaller amounts in the kidney and muscles. Elevated levels are often associated with liver damage. 

  • Bilirubin, Total: this is a measure of bilirubin in your blood. Bilirubin is an orange-yellowish waste product produced from the breakdown of heme which is a component of hemoglobin found in red blood cells. The liver is responsible for removal of bilirubin from the body. 

  • Bun/Creatinine Ratio: this is a ratio between your Urea Nitrogen (BUN) result and Creatinine result.  

  • Calcium: this is a measurement of calcium in your blood. Calcium is the most abundant and one of the most important minerals in the body as it essential for proper nerve, muscle, and heart function. 

  • Calcium: is used for blood clot formation and the formation and maintenance of bones and teeth. 

  • Carbon Dioxide: this is a measure of carbon dioxide in your blood. Carbon dioxide is a negatively charged electrolyte that works with other electrolytes such as chloride, potassium, and sodium to regulate the body’s acid-base balance and fluid levels.  

  • Chloride: this is a measure of Chloride in your blood. Chloride is a negatively charged electrolyte that works with other electrolytes such as potassium and sodium to regulate the body’s acid-base balance and fluid levels. 

  • Creatinine: this is a measure of Creatinine levels in your blood. Creatinine is created from the breakdown of creatine in your muscles and is removed from your body by the kidneys. Elevated creatinine levels are often associated with kidney damage. 

  • Egfr African American: this is a measure of how well your kidneys are functioning. Glomeruli are tiny filters in your kidneys that filter out waste products from your blood for removal while retaining important substances such as nutrients and blood cells. 

  • Egfr Non-Afr. American: this is a measure of how well your kidneys are functioning. Glomeruli are tiny filters in your kidneys that filter out waste products from your blood for removal while retaining important substances such as nutrients and blood cells. 

  • Globulin: this is a measure of all blood proteins in your blood that are not albumin. 

  • Glucose: this is a measure of glucose in your blood. Glucose is created from the breakdown of carbohydrates during digestion and is the body’s primary source of energy. 

  • Potassium: this is a measure of Potassium in your blood. Potassium is an electrolyte that plays a vital role in cell metabolism, nerve and muscle function, and transport of nutrients into cells and removal of wastes products out of cells. 

  • Protein, Total: this is a measure of total protein levels in your blood. 
    Sodium: this is a measure of Sodium in your blood. Sodium is an electrolyte that plays a vital role in nerve and muscle function. 

  • Sodium: this is a measure of sodium in your blood's serum. Sodium is a vital mineral for nerve and muscle cell function.

  • Urea Nitrogen (Bun): this is a measure of Urea Nitrogen in your blood, also known as Blood UreaNitrogen (BUN). Urea is a waste product created in the liver when proteins are broken down into amino acids. Elevated levels are often associated with kidney damage. 

Lab tests often ordered with a Comprehensive Metabolic Panel test: 

  • Complete Blood Count with Differential and Platelets
  • Iron and Total Iron Binding Capacity
  • Lipid Panel
  • Vitamin B12 and Folate
  • Prothrombin with INR and Partial Thromboplastin Times
  • Sed Rate (ESR)
  • C-Reactive Protein

Conditions where a Comprehensive Metabolic Panel test is recommended: 

  • Diabetes
  • Kidney Disease
  • Liver Disease
  • Hypertension

Commonly Asked Questions: 

How does my health care provider use a Comprehensive Metabolic Panel test? 

The comprehensive metabolic panel (CMP) is a broad screening tool for assessing organ function and detecting diseases like diabetes, liver disease, and kidney disease. The CMP test may also be requested to monitor known disorders such as hypertension and to check for any renal or liver-related side effects in persons taking specific drugs. If a health practitioner wants to follow two or more separate CMP components, the full CMP might be ordered because it contains more information. 

What do my Comprehensive Metabolic Panel test results mean? 

The results of the tests included in the CMP are usually analyzed together to look for patterns. A single abnormal test result may indicate something different than a series of abnormal test findings. A high result on one of the liver enzyme tests, for example, is not the same as a high result on several liver enzyme tests. 

Several sets of CMPs, frequently performed on various days, may be examined to gain insights into the underlying disease and response to treatment, especially in hospitalized patients. 

Out-of-range findings for any of the CMP tests can be caused by a variety of illnesses, including kidney failure, breathing issues, and diabetes-related complications, to name a few. If any of the results are abnormal, one or more follow-up tests are usually ordered to help determine the reason and/or establish a diagnosis. 

Is there anything else I should know? 

A wide range of prescription and over-the-counter medications can have an impact on the results of the CMP's components. Any medications you're taking should be disclosed to your healthcare professional. Similarly, it is critical to provide a thorough history because many other circumstances can influence how your results are interpreted. 

What's the difference between the CMP and the BMP tests, and why would my doctor choose one over the other? 

The CMP consists of 14 tests, while the basic metabolic panel (BMP) is a subset of those with eight tests. The liver (ALP, ALT, AST, and bilirubin) and protein (albumin and total protein) tests are not included. If a healthcare provider wants a more thorough picture of a person's organ function or to check for specific illnesses like diabetes or liver or kidney disease, he or she may prescribe a CMP rather than a BMP. 

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

Please note the following regarding BUN/Creatinine ratio: 

The lab does not report the calculation for the BUN/Creatinine Ratio unless one or both biomarkers’ results fall out of the published range. 

If you still wish to see the value, it's easy to calculate. Simply take your Urea Nitrogen (BUN) result and divide it by your Creatinine result.  

As an example, if your Urea Nitrogen result is 11 and your Creatinine result is 0.86, then you would divide 11 by 0.86 and get a BUN/Creatinine Ratio result of 12.79. 


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Description: A Creatinine test is a blood test that is used to evaluate the health of your kidneys and diagnose and monitor the treatment of kidney disease.

Also Known As: Create Test, Blood Creatinine Test, Serum Creatinine Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Creatinine test ordered?

During a health assessment, creatinine may be requested as part of a complete or basic metabolic panel. It may be ordered if a person is seriously ill or if a doctor feels that their kidneys aren't functioning properly.

When someone has a known renal condition or a disease that may impact kidney function, a creatinine blood test, coupled with a BUN test and urine albumin, may be ordered at regular intervals. When a CT scan is planned, before to and during some medication therapy, and before and after dialysis, both BUN and creatinine may be requested to assess the effectiveness of treatments.

What does a Creatinine blood test check for?

Creatinine is a waste product created by muscles when a molecule called creatine is broken down. The kidneys eliminate creatinine from the body by filtering almost all of it from the blood and excreting it in the urine. The level of creatinine in the blood and/or urine is measured in this test.

Creatine is a component of the energy-producing cycle that allows muscles to contract. The body produces both creatine and creatinine at a roughly steady rate. Because the kidneys filter almost all creatinine from the blood and excrete it in the urine, blood levels are usually an excellent predictor of how well the kidneys are operating. The amount produced is determined by the person's size and muscular mass. As a result, men's creatinine levels will be slightly higher than women's and children's.

A blood creatinine test's results can be combined with those from other tests, such as a 24-hour urine creatinine test, to produce calculations that are used to assess kidney function.

Lab tests often ordered with a Creatinine test:

  • BUN (Blood Urea Nitrogen)
  • Creatinine Clearance
  • Comprehensive Metabolic Panel (CMP)
  • Basic Metabolic Panel (BMP)
  • Urinalysis
  • Microalbumin and Creatinine Ratio
  • Cystatin C with eGFR
  • Beta-2 Microglobulin
  • Urine Protein

Conditions where a Creatinine test is recommended:

  • Kidney Disease
  • Diabetes
  • Proteinuria
  • Hypertension

How does my health care provider use a Creatinine test?

Kidney function is assessed with a creatinine blood test. It's usually requested in conjunction with a BUN test or as part of a basic or comprehensive metabolic panel, which consists of a series of tests designed to assess the operation of the body's primary organs. BMP or CMP tests are used to screen healthy persons during normal physical exams, as well as to help evaluate people who are acutely or chronically ill in the emergency room and/or hospital. Creatinine testing is sometimes done as part of a renal panel to assess kidney function.

Creatinine is a waste product created by muscles when a molecule called creatine is broken down. Because the kidneys filter almost all creatinine from the blood and discharge it into the urine, blood levels are usually an excellent predictor of how well the kidneys are operating.

The kidneys are a pair of bean-shaped organs placed on the right and left sides of the back at the bottom of the ribcage. Nephrons are a million microscopic blood filtering units found within them. Blood is continuously filtered by a small cluster of looping blood arteries called a glomerulus in each nephron. Water and tiny molecules flow through the glomerulus, but blood cells and bigger molecules are retained. Each glomerulus has a little tube attached to it that gathers the fluid and molecules that flow through it and then reabsorbs what the body can use. Urine is formed from the residual waste.

If the creatinine and BUN tests are abnormal, or if the patient has an underlying condition that affects the kidneys, such as diabetes or high blood pressure, creatinine and BUN tests may be used to monitor renal functionality and therapy effectiveness. Before some procedures, such as a CT scan, that may necessitate the use of medicines that can harm the kidneys, blood creatinine and BUN tests may be requested to assess renal function.

Creatinine test results can be utilized in calculations to determine renal function.

The estimated glomerular filtration rate, used as a screen to search for signs of early kidney damage, is calculated using blood creatinine readings, as well as age, weight, and sex.

What do my Creatinine test results mean?

Elevated creatinine levels in the blood indicate renal disease or other disorders affecting kidney function.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


This panel is designed for individuals diagnosed as having diabetes mellitus whose kidney disease has advanced to Stage 3/4 impairment. The panel affords the opportunity to assess electrolytes, phosphorus, serum creatinine/eGFR, hemoglobin, microalbumin, parathyroid hormone, calcium, and vitamin D. The grouping of these tests, readily identifiable as elements that adhere to guideline recommendations, is intended to facilitate the ready adherence to professional society clinical practice guidelines. Components of the testing related to the Management of CKD in diabetes, as outlined in the Standards of Medical Care in Diabetes 2013. These recommendations are in broad agreement with those published by the National Kidney Foundation and the American Association of Clinical Endocrinologists.

Clinical Significance

Phosphate, 24-Hour Urine with Creatinine - Phosphorus is present in many foods with a mean intake of approximately 1500 mg per day for adult males and about 1000 mg per day for adult females. Absorbed phosphate, under the influence of parathyroid hormone is readily excreted in the kidney. Measurement of urinary phosphorus generally reflects dietary intake hence, day-to-day excretion may show considerable variation.


Description: PTH is a hormone that is used to help maintain levels of calcium in the blood. A PTH test will measure the amount of PTH in the blood and can be used to make sure that the feedback loop is working correctly. 

Also Known As: Parathyroid hormone Intact test, Intact PTH test, Parathormone test

Collection Method: Blood Draw

Specimen Type: Plasma

Test Preparation: No preparation required

When is a PTH test ordered?

When a calcium test is abnormal, a PTH test may be requested. When someone shows signs of hypercalcemia or hypocalcemia, it may be prescribed.

When someone has been treated for an illness or condition that affects calcium control, such as the elimination of a parathyroid tumor, or when a person has a long - term condition like renal disease, a health practitioner may prescribe a PTH test along with a calcium test at intervals.

When someone with hyperparathyroidism is undergoing surgery to remove abnormal parathyroid tissue, an intraoperative PTH test may be done to confirm that all of the abnormal glands are removed, which can vary in number and position.

What does a PTH blood test check for?

The hormone parathyroid aids in the body's ability to keep calcium levels in the blood at a constant level. Calcium, PTH, vitamin D, and, to a lesser extent, phosphorus and magnesium are all part of a feedback loop. Conditions and disorders that disturb this feedback loop can lead to abnormal increases or declines in calcium and PTH levels, as well as hypercalcemia and hypocalcemia symptoms. This test determines how much PTH is present in the blood.

PTH is generated by four parathyroid glands, which are positioned behind the thyroid gland in the neck and are the size of a button. PTH is secreted into the bloodstream by these glands in reaction to low blood calcium levels. To help restore normal blood calcium levels, the hormone functions in three ways:

  • PTH encourages calcium to be released from the bones into the bloodstream.
  • It encourages the kidneys to convert vitamin D from inactive to active form, which enhances calcium absorption from food in the intestines.
  • It works on the kidneys to reduce calcium excretion in the urine while increasing phosphorus excretion.

PTH generally declines as calcium levels in the blood begin to rise.

The parathyroid hormone is made up of 84 amino acids. The parathyroid gland contains both intact and fragmented hormone, which it secretes. The intact hormone makes up a lesser percentage of the total, but its proportion rises when calcium levels are low and falls when calcium levels are high.

PTH has a relatively short half-life once released into the bloodstream; absorption and cleavage in the liver and kidneys cause levels to drop by 50% in less than 5 minutes. The pieces are known as C-terminal fragments, and they range in size from 6 amino acids to more than half of the molecule's N-terminal region. C-terminal fragments have a longer half-life, are found in higher concentrations, and are eventually eliminated by the kidneys. Although the C-terminal fragments were assumed to be inactive at first, it now appears that some of them may have biologic actions that are able to counteract those of whole PTH.

Lab tests often ordered with a PTH test:

  • Calcium
  • Phosphorus
  • Vitamin D

Conditions where a PTH test is recommended:

  • Parathyroid Disease
  • Kidney Disease
  • Hypercalcemia
  • Hypocalcemia

How does my health care provider use a PTH test?

The most commonly requested parathyroid hormone test is intact PTH. It's utilized to figure out what's causing a low or high calcium level, as well as to distinguish between parathyroid and non-parathyroid reasons. When a person has a parathyroid-related ailment, it can also be utilized to track the effectiveness of treatment. People with chronic renal disease or who are on dialysis have their PTH levels checked on a regular basis.

Almost always, a calcium test is ordered in conjunction with a PTH test. It's not just the calcium level in the blood that matters, but also the calcium-PTH balance and the parathyroid glands' response to fluctuating calcium levels. Typically, health professionals are concerned about severe calcium regulation imbalances that may necessitate medical intervention or recurring imbalances that signal an underlying disease.

PTH levels can be used to track persons who have chronic calcium imbalances due to illnesses or diseases, as well as those who have had surgery or another procedure for a parathyroid tumor.

What do my PTH test results mean?

A health professional will look at both calcium and PTH findings to see if they're in the right range and in balance. If both PTH and calcium levels are normal, the body's calcium regulating mechanism is likely to be in good working order.

Low levels of PTH can be caused by hypercalcemia or a defect in PTH generation, resulting in hypoparathyroidism. Hyperparathyroidism, which is most commonly caused by a benign parathyroid tumor, can produce excessive PTH secretion. Cancer may be the reason in some cases.

If calcium levels are low and PTH levels are high, the parathyroid glands are responding properly and producing enough PTH. A health practitioner may examine a low calcium level further by analyzing vitamin D, phosphorus, and magnesium levels, depending on the degree of hypocalcemia.

If calcium levels are low and PTH levels are normal or low, PTH isn't working properly, and the person being tested is most likely hypoparathyroid. The failure of the parathyroid glands to produce enough PTH causes hypoparathyroidism. It could be caused by a variety of factors and could be chronic, progressive, or transitory. An autoimmune problem, parathyroid injury or removal during surgery, a hereditary condition, or a serious sickness are all possible causes. PTH levels will be low, calcium levels will be low, and phosphorus levels will be high in those who are impacted.

If your calcium levels are high and your PTH levels are high, your parathyroid glands are producing too much PTH. To help diagnose the origin and severity of hyperparathyroidism, a health practitioner may order X-rays or other imaging procedures. Primary, secondary, and tertiary hyperparathyroidism are three types of hyperparathyroidism characterized by an excess of PTH produced by the parathyroid glands.

If calcium levels are high and PTH levels are low, the parathyroid glands are functioning normally. However, a health practitioner will likely conduct additional tests to rule out non-parathyroid causes for the elevated calcium, such as genetic variants in calcium receptors or tumors that secrete a peptide with PTH-like activity, which increases calcium concentration while decreasing PTH.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


Description: PTH is a hormone that is used to help maintain levels of calcium in the blood. A PTH and Calcium test will measure the amount of PTH and calcium in the blood and can be used to make sure that the feedback loop is working correctly. 

Also Known As: Parathyroid hormone Intact (with Calcium) test, Intact PTH test, Parathormone test, PTH with Calcium Test, Parathyroid Hormone Intact with Calcium Test, Intact PTH with Calcium Test, PTH with Ca Test

Collection Method: Blood Draw

Specimen Type: Plasma and Serum

Test Preparation: No preparation required

When is a PTH Intact with Calcium test ordered?

When a calcium test is abnormal, a PTH and Calcium test may be requested. When someone shows signs of hypercalcemia or hypocalcemia, it may be prescribed.

When someone has been treated for an illness or condition that affects calcium control, such as the elimination of a parathyroid tumor, or when a person has a long - term condition like renal disease, a health practitioner may prescribe a PTH test along with a calcium test at intervals.

When someone with hyperparathyroidism is undergoing surgery to remove abnormal parathyroid tissue, an intraoperative PTH test may be done to confirm that all of the abnormal glands are removed, which can vary in number and position.

What does a PTH Intact and Calcium test check for?

The hormone parathyroid aids in the body's ability to keep calcium levels in the blood at a constant level. Calcium, PTH, vitamin D, and, to a lesser extent, phosphorus and magnesium are all part of a feedback loop. Conditions and disorders that disturb this feedback loop can lead to abnormal increases or declines in calcium and PTH levels, as well as hypercalcemia and hypocalcemia symptoms. This test determines how much PTH is present in the blood.

PTH is generated by four parathyroid glands, which are positioned behind the thyroid gland in the neck and are the size of a button. PTH is secreted into the bloodstream by these glands in reaction to low blood calcium levels. To help restore normal blood calcium levels, the hormone functions in three ways:

  • PTH encourages calcium to be released from the bones into the bloodstream.
  • It encourages the kidneys to convert vitamin D from inactive to active form, which enhances calcium absorption from food in the intestines.
  • It works on the kidneys to reduce calcium excretion in the urine while increasing phosphorus excretion.

PTH generally declines as calcium levels in the blood begin to rise.

The parathyroid hormone is made up of 84 amino acids. The parathyroid gland contains both intact and fragmented hormone, which it secretes. The intact hormone makes up a lesser percentage of the total, but its proportion rises when calcium levels are low and falls when calcium levels are high.

PTH has a relatively short half-life once released into the bloodstream; absorption and cleavage in the liver and kidneys cause levels to drop by 50% in less than 5 minutes. The pieces are known as C-terminal fragments, and they range in size from 6 amino acids to more than half of the molecule's N-terminal region. C-terminal fragments have a longer half-life, are found in higher concentrations, and are eventually eliminated by the kidneys. Although the C-terminal fragments were assumed to be inactive at first, it now appears that some of them may have biologic actions that are able to counteract those of whole PTH.

Calcium is one of the most plentiful and vital minerals in the human body. It is required for cell signaling as well as the proper operation of muscles, nerves, and the heart. Calcium is essential for blood clotting as well as bone growth, density, and maintenance. This test determines how much calcium is present in the blood.

Calcium is found complexed in the bones for 99 percent of the time, while the remaining 1% circulates in the blood. Calcium levels are closely monitored; if too little is absorbed or consumed, or if too much is lost through the kidney or stomach, calcium is removed from bone to keep blood concentrations stable. Approximately half of the calcium in the blood is metabolically active and "free." The other half is "bound" to albumin, with a minor proportion complexed to anions like phosphate, and both of these forms are metabolically inactive.

Blood calcium can be measured using two different tests. The free and bound forms of calcium are measured in the total calcium test. Only the free, physiologically active form of calcium is measured in the ionized calcium test.

Lab tests often ordered with a PTH Intact and Calcium test:

  • Phosphorus
  • Vitamin D
  • Magnesium
  • Albumin
  • Basic Metabolic Panel (BMP)
  • Comprehensive Metabolic Panel (CMP)

Conditions where a PTH Intact and Calcium test is recommended:

  • Kidney Disease
  • Thyroid Disease
  • Alcoholism
  • Malnutrition
  • Parathyroid Diseases
  • Breast Cancer
  • Multiple Myeloma
  • Hypercalcemia
  • Hypocalcemia

How does my health care provider use a PTH Intact and Calcium test?

The most commonly requested parathyroid hormone test is intact PTH. It's utilized to figure out what's causing a low or high calcium level, as well as to distinguish between parathyroid and non-parathyroid reasons. When a person has a parathyroid-related ailment, it can also be utilized to track the effectiveness of treatment. People with chronic renal disease or who are on dialysis have their PTH levels checked on a regular basis.

Almost always, a calcium test is ordered in conjunction with a PTH test. It's not just the calcium level in the blood that matters, but also the calcium-PTH balance and the parathyroid glands' response to fluctuating calcium levels. Typically, health professionals are concerned about severe calcium regulation imbalances that may necessitate medical intervention or recurring imbalances that signal an underlying disease.

PTH levels can be used to track persons who have chronic calcium imbalances due to illnesses or diseases, as well as those who have had surgery or another procedure for a parathyroid tumor.

What do my Parathyroid Hormone with Calcium test results mean?

A health professional will look at both calcium and PTH findings to see if they're in the right range and in balance. If both PTH and calcium levels are normal, the body's calcium regulating mechanism is likely to be in good working order.

Low levels of PTH can be caused by hypercalcemia or a defect in PTH generation, resulting in hypoparathyroidism. Hyperparathyroidism, which is most commonly caused by a benign parathyroid tumor, can produce excessive PTH secretion. Cancer may be the reason in some cases.

If calcium levels are low and PTH levels are high, the parathyroid glands are responding properly and producing enough PTH. A health practitioner may examine a low calcium level further by analyzing vitamin D, phosphorus, and magnesium levels, depending on the degree of hypocalcemia.

If calcium levels are low and PTH levels are normal or low, PTH isn't working properly, and the person being tested is most likely hypoparathyroid. The failure of the parathyroid glands to produce enough PTH causes hypoparathyroidism. It could be caused by a variety of factors and could be chronic, progressive, or transitory. An autoimmune problem, parathyroid injury or removal during surgery, a hereditary condition, or a serious sickness are all possible causes. PTH levels will be low, calcium levels will be low, and phosphorus levels will be high in those who are impacted.

If your calcium levels are high and your PTH levels are high, your parathyroid glands are producing too much PTH. To help diagnose the origin and severity of hyperparathyroidism, a health practitioner may order X-rays or other imaging procedures. Primary, secondary, and tertiary hyperparathyroidism are three types of hyperparathyroidism characterized by an excess of PTH produced by the parathyroid glands.

If calcium levels are high and PTH levels are low, the parathyroid glands are functioning normally. However, a health practitioner will likely conduct additional tests to rule out non-parathyroid causes for the elevated calcium, such as genetic variants in calcium receptors or tumors that secrete a peptide with PTH-like activity, which increases calcium concentration while decreasing PTH.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


The hormone Parathyroid Hormone (PTH) acts to increase serum calcium and 1-, 25- dihydroxyvitamin D concentrations, while decreasing phosphorus. Cross-reactivity with fragment 7-84 may occur in patients with renal insufficiency. The BioIntact PTH assay is considered the most reliable. Parathyroid function is related to the calcium concentration so both results should be interpreted together.


Surgical treatment of hyperparathyroidism relies on the ability to accurately identify parathyroid tissue. The use of fine-needle aspirate (FNA) with measurement of intact parathyroid hormone (PTH) levels in suspected parathyroid cysts or adenomas is used to identify parathyroid tissue and has been proven to be a useful surgical adjunct in the treatment of hyperparathyroidism.


Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead hypercalcemia. This assay employs liquid chromatography tandem mass spectrometry to independently measure and report the two common forms of 25-hydroxy vitamin D: 25OH D3 - the endogenous form of the vitamin and 25OH D2 - the analog form used to treat 25OH Vitamin D3 deficiency. While this assay will produce accurate Vitamin D results on patients of any age, it is specifically indicated for infants less than 3 years of age.


Description: A Vitamin D test is a blood test used to determine if you have a Vitamin D deficiency and to monitor Vitamin D levels if you are on supplementation. 

Also Known As: 25-hydroxyvitamin D Test, Vitamin D 25-Hydroxyvitamin Test 

Collection Method: Blood Draw 

Specimen Type: Serum 

Test Preparation: Fasting preferred, but not required. 

When is a Vitamin D test ordered?

When calcium levels are inadequate and/or a person exhibits symptoms of vitamin D deficiency, such as rickets in children and bone weakening, softness, or fracture in adults, 25-hydroxyvitamin D is frequently ordered to rule out a vitamin D deficit. 

When a person is suspected of having a vitamin D deficiency, the test may be requested. Vitamin D deficiency is more common in older folks, people who are institutionalized or homebound and/or have minimal sun exposure, people who are obese, have had gastric bypass surgery, and/or have fat malabsorption. People with darker skin and breastfed babies are also included in this category. 

Before starting osteoporosis medication, 25-hydroxyvitamin D is frequently requested. 

What does a Vitamin D blood test check for? 

Vitamin D is a group of chemicals that are necessary for the healthy development and growth of bones and teeth. The level of vitamin D in the blood is determined by this test. 

Vitamin D is tested in the blood in two forms: 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. The primary form of vitamin D found in the blood is 25-hydroxyvitamin D, which is a relatively inactive precursor to the active hormone 1,25-dihydroxyvitamin D. 25-hydroxyvitamin D is routinely evaluated to assess and monitor vitamin D status in humans due to its longer half-life and higher concentration. 

Vitamin D's major function is to assist balance calcium, phosphorus, and magnesium levels in the blood. Vitamin D is necessary for bone growth and health; without it, bones become fragile, misshapen, and unable to mend themselves properly, leading to disorders such as rickets in children and osteomalacia in adults. Vitamin D has also been proven to influence the growth and differentiation of a variety of other tissues, as well as to aid in immune system regulation. Other illnesses, such as autoimmune and cancer, have been linked to vitamin D's other roles. 

According to the Centers for Disease Control and Prevention, two-thirds of the US population has adequate vitamin D, while one-quarter is at risk of inadequate vitamin D and 8% is at risk of insufficiency, as defined by the Institute of Medicine's Dietary Reference Intake. 

The elderly or obese, persons who don't receive enough sun exposure, people with darker skin, and people who take certain drugs for lengthy periods of time are all at risk of insufficiency. Adequate sun exposure is usually defined as two intervals of 5-20 minutes each week. Vitamin D can be obtained through dietary sources or supplements by people who do not get enough sun exposure. 

Lab tests often ordered with a Vitamin D test: 

  • Complete Blood Count 
  • CMP 
  • Iron and TIBC 
  • Calcium 
  • Phosphorus 
  • PTH 
  • Magnesium

Conditions where a Vitamin D test is recommended:

  • Kidney Disease 
  • Osteoporosis 
  • Lymphoma 
  • Cystic Fibrosis 
  • Autoimmune Disorders 
  • Celiac Disease 
  • Malabsorption 
  • Malnutrition 

Commonly Asked Questions: 

How does my health care provider use a Vitamin D test? 

Determine whether a deficit or excess of vitamin D is causing bone weakening, deformity, or improper calcium metabolism. 

Because PTH is required for vitamin D activation, it can aid in diagnosing or monitoring problems with parathyroid gland function. 

Because vitamin D is a fat-soluble vitamin that is absorbed from the intestine like a fat, it can help monitor the health of people with conditions that interfere with fat absorption, such as cystic fibrosis and Crohn's disease. 

People who may not be able to absorb vitamin D adequately or have had gastric bypass surgery should be closely monitored. 

When vitamin D, calcium, phosphorus, and/or magnesium supplementation is suggested, it can help assess the success of the treatment. 

What do my Vitamin D results result mean? 

Even though vitamin D techniques differ, most laboratories use the same reference intervals. Because toxicity is uncommon, researchers have focused on the lower limit and what cut-off for total 25-hydroxyvitamin D shortage implies. 

A low blood level of 25-hydroxyvitamin D could indicate that a person isn't getting enough sunlight or dietary vitamin D to meet his or her body's needs, or that there's an issue with absorption from the intestines. Seizure medications, notably phenytoin, might occasionally interfere with the liver's generation of 25-hydroxyvitamin D. 

Vitamin D insufficiency has been linked to an increased risk of some malignancies, immunological illnesses, and cardiovascular disease. 

Excessive supplementation with vitamin pills or other nutritional source of vitamin D frequently results in a high level of 25-hydroxyvitamin D. 

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.


Brief Description: A Vitamin D test is a blood test used to determine if you have a Vitamin D deficiency and to monitor Vitamin D levels if you are on supplementation.

Also Known As: Ergocalciferol Test, Vitamin D2 Test, Cholecalciferol Test, Vitamin D3 Test, Calcidiol Test, 25-hydroxyvitamin D Test, Calcifidiol Test, 25-hydroxy-vitamin D Test, Vitamin D Total Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting preferred, but not required.

When is a Vitamin D test ordered?

When calcium levels are inadequate and/or a person exhibits symptoms of vitamin D deficiency, such as rickets in children and bone weakening, softness, or fracture in adults, 25-hydroxyvitamin D is frequently ordered to rule out a vitamin D deficit.

When a person is suspected of having a vitamin D deficiency, the test may be requested. Vitamin D deficiency is more common in older folks, people who are institutionalized or homebound and/or have minimal sun exposure, people who are obese, have had gastric bypass surgery, and/or have fat malabsorption. People with darker skin and breastfed babies are also included in this category.

Before starting osteoporosis medication, 25-hydroxyvitamin D is frequently requested.

What does a Vitamin D blood test check for?

Vitamin D is a group of chemicals that are necessary for the healthy development and growth of teeth and bones. The level of vitamin D in the blood is determined by this test.

Vitamin D is tested in the blood in two forms: 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. The primary form of vitamin D found in the blood is 25-hydroxyvitamin D, which is a relatively inactive precursor to the active hormone 1,25-dihydroxyvitamin D. 25-hydroxyvitamin D is routinely evaluated to assess and monitor vitamin D status in humans due to its longer half-life and higher concentration.

Endogenous vitamin D is created in the skin when exposed to sunshine, whereas exogenous vitamin D is taken through foods and supplements. Vitamin D2 and vitamin D3 have somewhat different molecular structures. Fortified foods, as well as most vitamin preparations and supplements, include the D2 form. The type of vitamin D3 produced by the body is also used in some supplements. When the liver and kidneys convert vitamin D2 and D3 into the active form, 1,25-dihydroxyvitamin D, they are equally effective.

Some tests may not differentiate between the D2 and D3 forms of vitamin D and just report the total result. Newer methods, on the other hand, may record D2 and D3 levels separately and then sum them up to get a total level.

Vitamin D's major function is to assist balance calcium, phosphorus, and magnesium levels in the blood. Vitamin D is necessary for bone growth and health; without it, bones become fragile, misshapen, and unable to mend themselves properly, leading to disorders such as rickets in children and osteomalacia in adults. Vitamin D has also been proven to influence the growth and differentiation of a variety of other tissues, as well as to aid in immune system regulation. Other illnesses, such as autoimmune and cancer, have been linked to vitamin D's other roles.

According to the Centers for Disease Control and Prevention, two-thirds of the US population has adequate vitamin D, while one-quarter is at risk of inadequate vitamin D and 8% is at risk of insufficiency, as defined by the Institute of Medicine's Dietary Reference Intake.

The elderly or obese, persons who don't receive enough sun exposure, people with darker skin, and people who take certain drugs for lengthy periods of time are all at risk of insufficiency. Adequate sun exposure is usually defined as two intervals of 5-20 minutes each week. Vitamin D can be obtained through dietary sources or supplements by people who do not get enough sun exposure.

This test has 3 Biomarkers

  • Vitamin D Total which is a combined measurement of Vitamin D, 25-Oh, D2 and Vitamin 25-Oh, D3
  • Vitamin D, 25-Oh, D2 which is a measurement of ergocalciferol Vitamin D, which is Vitamin D obtained through plant sources. 
  • Vitamin D, 25-Oh, D3 which is a measurement of cholecalciferol Vitamin D, which is Vitamin D obtained through animal sources.

Lab tests often ordered with a Vitamin D test:

  • Complete Blood Count
  • CMP
  • Iron and TIBC
  • Calcium
  • Phosphorus
  • PTH
  • Magnesium

Conditions where a Vitamin D test is recommended:

  • Kidney Disease
  • Osteoporosis
  • Lymphoma
  • Cystic Fibrosis
  • Autoimmune Disorders
  • Celiac Disease
  • Malabsorption
  • Malnutrition

Commonly Asked Questions:

How does my health care provider use a Vitamin D test?

Determine whether a deficit or excess of vitamin D is causing bone weakening, deformity, or improper calcium metabolism.

Because PTH is required for vitamin D activation, it can aid in diagnosing or monitoring problems with parathyroid gland function.

Because vitamin D is a fat-soluble vitamin that is absorbed from the intestine like a fat, it can help monitor the health of people with conditions that interfere with fat absorption, such as cystic fibrosis and Crohn's disease.

People who have had gastric bypass surgery and may not be able to absorb adequate vitamin D should be closely monitored.

When vitamin D, calcium, phosphorus, and/or magnesium supplementation is suggested, it can help assess the success of the treatment.

What do my Vitamin D results result mean?

Despite the fact that vitamin D techniques differ, most laboratories use the same reference intervals. Because toxicity is uncommon, researchers have focused on the lower limit and what cut-off for total 25-hydroxyvitamin D shortage implies.

A low blood level of 25-hydroxyvitamin D could indicate that a person isn't getting enough sunlight or dietary vitamin D to meet his or her body's needs, or that there's an issue with absorption from the intestines. Seizure medications, notably phenytoin, might occasionally interfere with the liver's generation of 25-hydroxyvitamin D.

Vitamin D insufficiency has been linked to an increased risk of some malignancies, immunological illnesses, and cardiovascular disease.

Excessive supplementation with vitamin pills or other nutritional supplements frequently results in a high level of 25-hydroxyvitamin D.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.



The average person has four parathyroid glands. These glands are button-sized and are situated at the base of the throat near the thyroid gland. Parathyroid glands produce a hormone called parathyroid (PTH) that is responsible for regulating the quantity of calcium in the blood.

Calcium is a mineral that is essential in the formation of bones, teeth, clotting of blood, and proper functioning of the heart, nerves, and muscles. About 99% of the calcium in the human body is found in the bones and teeth, while the rest circulates in the blood. Some calcium is eliminated from the body every day through urine.

To regulate the amount of calcium in the blood, the parathyroid hormone acts as part of a feedback system that includes vitamin D, phosphorus (as phosphate), and calcium. Phosphorus is another mineral that collaborates with calcium in its numerous operations in the body. Most of it combines with calcium to assist in the formation of teeth and bones. Vitamin D boosts the absorption of phosphate and calcium in the digestive system.

The parathyroid glands’ role is to ensure that the amount of calcium in the blood remains within a specific range. As the amount of calcium in the blood reduces, the parathyroid glands produce and release PTH, which works to increase the amount of calcium in the blood in 3 ways:

PTH triggers the kidneys to reduce the removal of calcium through urine and increase the removal of phosphate through urine.

It acts on the kidneys to transform vitamin D from the inactive to the active state. This, in turn, increases the quantity of calcium absorbed from food in the digestive system.

It boosts the release of calcium from bones into the bloodstream.

As the amount of calcium in the blood gets higher, the production of PTH by the parathyroid glands reduces. This feedback system ensures a dynamic but relatively stable concentration of calcium in the blood.

Parathyroid illnesses are conditions that affect the quantity of PTH (parathyroid hormone) produced, which in turn affects the amount of calcium in the bloodstream.

Hyperparathyroidism

Hyperparathyroidism is a condition characterized by the production of excess PTH by the parathyroid glands. It is divided into three groups: primary, secondary, and tertiary.

Primary hyperparathyroidism is a disease where the parathyroid glands are dysfunctional—the disease results in excess PTH in the blood as well as excess calcium in the blood. Since calcium is derived from the bones, they, in turn, become weak over time, increasing the risk of fractures.

About 85% of primary hyperparathyroidism cases are caused by a benign tumor (adenoma) in a single parathyroid gland. Less common causes are as a result of multiple adenomas or hyperplasia (an increase in the activity and size of 2 or more parathyroid glands). Very rare cases of the disease (less than 1%) are caused by parathyroid cancer, where tumors cause the production of excess PTH.

About 100,000 individuals in the U.S suffer from primary hyperparathyroidism each year. The disease is more common in individuals aged over 50 years and is more prevalent in women than men. In rare scenarios, the condition is caused by a genetic, endocrine syndrome (Men 1 or Men 2).

Secondary hyperparathyroidism is caused by low concentrations of calcium in the blood, which can happen due to the following:

  • Kidney failure: this can cause low amounts of active Vitamin D and elevated levels of phosphate, which lead to increased production of PTH.
  • Vitamin D deficiency.
  • Low calcium absorption caused by gastrointestinal disorders.
  • Tertiary hyperparathyroidism is rare and occurs when the main cause behind secondary hyperparathyroidism is fixed, but the parathyroid glands continue to over-produce PTH.

Hypoparathyroidism

Hypoparathyroidism is a PTH deficiency, and it can be a temporary or permanent condition. Hypoparathyroidism is not as common as hyperparathyroidism. Regardless of the cause, individuals with hypoparathyroidism have an elevated blood phosphorus level and a lower blood calcium level that may be mild or severe.

The leading cause of this condition is the removal of the parathyroid glands during surgical procedures necessary for the treatment of other conditions. Parathyroid glands may need to be removed if you have cancer of the throat or thyroid cancer. Surgery may also be necessary when treating hyperparathyroidism caused by hyperplasia (increase in the activity and size of the parathyroid glands). About 3 or 3.5 glands are removed, and the remaining glands or part of a gland can be auto transplanted to an individual’s forearm. If the remaining gland does not work as expected, hypoparathyroidism may occur.

In some cases, it is caused by damage to all parathyroid glands by an autoimmune condition.

In rare cases, it is caused by a failure of the glands to develop correctly.

Temporary hypoparathyroidism may occur soon after undergoing treatment for hyperparathyroidism. This is known as hungry bone syndrome and happens when PTH decreases rapidly, and the bones are forced to seek calcium from the bloodstream. It can also be observed in newly born infants whose mothers have hyperparathyroidism.

Radiotherapy for cancer patients that affects the neck or face: Too much exposure to radiation can damage the parathyroid glands.

Low levels of magnesium in the blood: normal levels of magnesium are necessary for PTH production and release.

Signs and Symptoms

Signs and symptoms of parathyroid disease are closely related with those of an individual with a low blood calcium concentration (hypocalcemia) that occurs with hypoparathyroidism or high blood calcium concentration (hypercalcemia) that occurs with hyperparathyroidism.

Some examples include:

  • Low calcium (hypothyroidism)
  • Depression or anxiety
  • Dry skin, brittle nails
  • Hair loss
  • Painful menstrual periods
  • Fatigue
  • Numbness and tingling sensations in the lips, toes, and fingers
  • Muscle cramps or twitching
  • Abdominal pain
  • High calcium (hyperparathyroidism):
  • Depression
  • Constipation
  • Kidney stones (excess calcium in the urine can crystalize and form stones)
  • Bone pain and fragile bones
  • Frequent urination
  • Feeling very thirsty
  • Abdominal pain, loss of appetite, nausea,
  • Fatigue

Many people with parathyroid disease are diagnosed at an early stage with minimal or no complications, but others may experience mild to severe complications before seeking medical care.

Tests

Testing is done to monitor, diagnose, and detect parathyroid diseases. The first sign of parathyroid disease may be an irregular blood calcium result on a routine blood test (like a CMP- Comprehensive Metabolic Panel). Some of the tests used to diagnose the parathyroid glands are noted below.

Some of the test results for patients with hyperparathyroidism include:

Calcium – elevated calcium levels, although many conditions may cause increased levels of calcium in the blood, so the test must be repeated multiple times to ascertain the cause.

PTH (parathyroid hormone)- usually elevated.

Urine calcium (one-day urine) – may be elevated due to hyperparathyroidism.

Some of the test results for patients with hypoparathyroidism include:

  • Low magnesium
  • High phosphate
  • Low PTH
  • Low calcium

Vitamin D – this test may be undertaken to establish whether an individual has a vitamin D deficiency that may be affecting calcium concentration in the blood.