What is the Corrected Calcium Test?
Calcium is among the minerals critical to the functionality of the body and is important for the bone system, muscle contraction, neural communication, and hemostasis. Calcium within the bloodstream is found in several different forms which include:
- Ionized (free) calcium: The ionized form of calcium that is biologically active.
- Protein-bound calcium: Mostly, the calcium is bound to albumin.
- Complexed calcium: Bound to other substances such as phosphate or citrate.
A standard serum calcium test measures total calcium, which includes both bound and free calcium. Calcium bonds with albumin, so if the albumin concentration is insufficient it can result in deceptively low total calcium readings. The corrected calcium measures the levels of calcium and the levels of albumin and adjusts the total calcium level based on the albumin concentration to provide a more accurate estimate of the biologically active calcium. Corrected calcium is useful in measuring cases of renal impairment, liver impairment, malnutrition, and other disorders.
How is the Test Performed?
The corrected calcium test is a straightforward test that includes a blood draw;
Preparation
- Fasting is not required generally
- Avoid intake of excessive calcium or vitamin D supplements
- Keep yourself hydrated
- Inform your doctor about the medications you are taking to avoid false results.
Sample collection
- A trained phlebotomist draws blood from the vein typically the arm using a needle
Laboratory Analysis
- The sample is then sent to the laboratory for further analysis using automated chemistry analyzers to measure the levels of calcium and albumin which is then calculated for the corrected calcium.
What are the symptoms that prompt this test?
The corrected calcium test is recommended by the healthcare provider if an individual is showing symptoms of calcium deficiency or excessive calcium in the blood. Common symptoms include the following:
Symptoms of Low Calcium
- Cramps, spasms, or twitching of the muscles in hands, feet, or face
- Numbness or tingling
- Weakness
- Fatigue
- Brittle nails
- Skin dryness
- Confusion
- Concentration difficulties
Symptoms of High Calcium
- Urinating frequently
- Nausea
- Vomiting
- Loss of appetite
- Constipation
- Pain in the abdomen
- Fatigue
- Formation of stones in kidneys
- Increased blood pressure
What are Normal Ranges for This Test?
The normal values for the Corrected Calcium vary according to the age and gender of an individual. The reference range is given below;
- Adults– 5 to 10.2 mg/dL
- Children – 8 to 10.8 mg/dL
- Newborns – 4 to 10.6 mg/dL
**The reference is given according to the corrected calcium level after measuring the albumin levels. If albumin levels are low the corrected calcium is adjusted accordingly.**
What Happens if Test Results Show Abnormal Levels?
Abnormal levels of corrected calcium are an indication of an underlying health issue that needs further testing and early management of the disease;
Elevated Levels of Corrected Calcium
- Hyperparathyroidism
- Cancer
- Vitamin D or overdose of calcium
- Kidney disorders
- Increased immobilization
Lower Levels of Corrected Calcium
- Hypoparathyroidism
- Chronic illnesses or malnutrition
- Vitamin D deficiency
- Kidney disorders
- Lowered magnesium levels
Further testing and treatments are given such as calcium supplements, vitamin D therapy, dietary changes, and surgery according to the needs of the patients.
