Hypocalcemia is a decrease in calcium levels in the blood that, in most cases, does not cause any type of symptoms and is usually identified in the results of the blood test. However, when the amount of calcium is too low, serious symptoms such as muscle spasms, mental confusion and seizures can occur.
Generally, hypocalcemia appears when the body is unable to maintain normal circulating levels of free calcium, as occurs in hypoparathyroidism or lack of vitamin D, for example, and treatment is carried out according to the cause, taking into account the severity of the condition. condition and whether or not there are symptoms, making calcium supplementation necessary.
Calcium is an essential mineral for bone health and the body's metabolism, and its levels in the blood are essentially regulated by the parathyroid gland and vitamin D, which balance the absorption of calcium in the diet, distribution in the bones and in the body or its elimination through the kidneys. Find out more about the functions and benefits of calcium for the body.
What are the causes
The main causes of hypocalcemia include:
- Hypoparathyroidism, especially when there is damage or removal of the parathyroids, which can occur through neck surgery, such as during thyroid removal, or irradiation during cancer treatment, for example;
- Pseudohypoparathyroidism, when the body loses sensitivity and is unable to respond to PTH levels, which is the parathyroid hormone;
- Deficiencies in parathyroid development, such as DiGeorge syndrome, which affects babies;
- Vitamin D deficiency;
- Low intake or poor absorption of calcium;
- Kidney diseases, which make it difficult to activate vitamin D and can cause greater excretion of calcium in the urine;
- Side effect of certain medications, such as Asparaginase, Cisplatin, Rifampicin, Ketoconazole, anticonvulsants or bisphosphonates, for example;
- Changes in the levels of other mineral salts that interfere with calcium levels, such as excess phosphate or lack of magnesium;
- Chronic alcoholism.
Furthermore, hypocalcemia can be a complication of acute pancreatitis, as fatty acids released by the inflamed pancreas can interfere with the amount of calcium.
How to confirm
Hypocalcemia is diagnosed through the measurement of free calcium in the blood, called ionic calcium, which is below normal levels, which must be between 4 and 5 mg/dl and the measurement of total calcium indicates that it is lacking when below 8 .5 mg/dl. However, these values may vary depending on the laboratory that performs the test. Also check out what happens when there is excess calcium in the blood.
However, the doctor may still need to test the kidneys, hormones and levels of other components in the blood, such as PTH, vitamin D, phosphorus and magnesium, for example, to identify the possible cause of the problem.
Main symptoms of Hypocalcemia
Although hypocalcemia does not present symptoms in milder cases, when calcium levels become very low or drop abruptly, signs such as:
- Muscle cramps and spasms;
- Tingling in the mouth, hands and feet;
- Nausea and vomiting;
- Abdominal cramps;
- Asthma attack.
When hypocalcemia is chronic and appears gradually, as happens in hypoparathyroidism, dry skin, brittle nails, hair loss and erosion of teeth can also be noticed, as well as nervousness, anxiety, mental confusion, memory changes and tremors. Learn about other common symptoms of this problem.
How the treatment is carried out
The treatment of hypocalcemia depends on the cause, the severity of the condition and the presence or absence of symptoms. When there is severe hypocalcemia with symptoms, calcium replacement, such as calcium gluconate or calcium chloride, via vein is necessary until symptoms are relieved.
In cases of mild hypocalcemia, calcium supplements and increased intake of foods with calcium may be indicated. See a list of foods rich in calcium.
It is also necessary to investigate the cause and resolve it, which may include replacing magnesium, vitamin D, as well as treating kidney or parathyroid changes, if they are the reason for hypocalcemia.
- HINRICHSEN, Sylvia L. Causes of…: Differential diagnosis. 1 ed. Rio de Janeiro: Medbook, 2014. 278-280.