Calcium Serum Test
The Calcium Serum Test measures calcium levels in the blood to help screen for, diagnose, and monitor various conditions related to the bones, heart, nerves, kidneys, and teeth.
What is Calcium?
Calcium is one of the most essential minerals found in the body. Calcium helps the body to sustain healthy bones and teeth. In addition, calcium also plays a part in ensuring that the heart, muscles, and nerves are functioning correctly. The majority of the calcium in the body is located in the bones, while the remainder circulates in the blood. Therefore, calcium levels are strictly regulated. A calcium deficiency due to malabsorption or excess loss through the kidney or gut can lead to calcium being taken from bone to maintain blood concentrations. Approximately half of the calcium circulating in the blood is “free” and metabolically active. In contrast, the remaining half is “bound” to proteins, such as albumin and globulins, with a smaller amount fused to anions like phosphate. Thus these bound and complex forms are metabolically inactive.
What is the purpose of this test?
It is usual for some calcium to be lost daily, as it is filtered from the bloodstream by the kidneys and excreted into the urine and sweat. This Calcium Serum Test measures both the free and bound forms of calcium to help screen for, diagnose, and monitor various conditions related to the bones, heart, nerves, kidneys, and teeth.
This test may be helpful for individuals with the following health conditions:
- Bone diseases
- Abnormal vitamin D level
- Chronic kidney disease
- Overactive thyroid gland
- Taking too much thyroid hormone medications
- Certain cancers, including breast, lung, kidney, neck, and multiple myeloma
- Chronic liver disease
- Intestinal absorption issues
- Disorders of the parathyroid glands
What causes abnormal calcium levels?
Several health conditions may cause abnormal calcium levels. Higher than average calcium levels may be caused by the following:
- Bed rest for an extended period
- Consuming too much vitamin D or calcium
- Certain cancers, multiple myeloma, and T-cell lymphoma
- Metastatic bone tumor
- Infections causing granulomas such as tuberculosis, fungal and mycobacterial infections
- Paget disease
- Tumors that produce a parathyroid hormone-like substance
- Taking medications such as lithium, tamoxifen, and thiazides
Additionally, lower-than-average calcium levels may be due to the following:
- Intestinal absorption issues
- Kidney failure
- Liver disease
- Deficiencies of albumin, magnesium, or vitamin D
When should I order a Calcium Serum Test?
Individuals may order this Calcium Serum Test if they have experienced symptoms related to abnormal calcium levels in the blood. For example, individuals with abnormal blood calcium levels may experience the following symptoms:
- Increased thirst
- Frequent urination
- Mental changes, such as fatigue or confusion
- Bone pain
- Muscle twitching
- Muscle weakness
- Digestive upset, including nausea, appetite loss, and constipation
- Muscle cramps
- Dry skin
- Brittle fingernails
- Tingling in the lips, fingers, or feet
- Abnormal heart rhythm
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