All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Calcitonin in the blood
Medical expert of the article
Last reviewed: 05.07.2025
Reference values (norm) for serum calcitonin concentration are less than 150 pg/ml (ng/l).
Calcitonin is a peptide hormone consisting of 32 amino acids and produced by the cells of the parafollicular epithelium (C-cells) of the thyroid gland. The half-life of the hormone is 5-8 minutes. Normally, calcitonin is involved in the regulation of calcium metabolism, being a physiological antagonist of PTH. In osteocytes, it inhibits enzymes that destroy bonetissue; in renal tubular cells, calcitonin causes increased clearance and release of Ca2+, phosphates , Mg 2+, K + , Na + and thereby helps reduce the concentration of Ca 2+ in the blood. The synthesis and release of calcitonin is regulated by the concentration of Ca 2+ in the blood: its increase stimulates the synthesis and secretion of the hormone, and a decrease inhibits these processes. In addition,gastrin and glucagon stimulate the secretion of calcitonin.
In clinical practice, the determination of calcitonin is necessary for the diagnosis of medullary thyroid cancer, since with this disease its content in the blood increases significantly, as well as for a comprehensive assessment of calcium metabolism disorders (together with PTH and vitamin D3 ).
Determination of calcitonin is of exceptional importance for diagnostics of medullary thyroid cancer. Increase of basal and stimulated concentration of calcitonin in blood serum during provocative test with pentagastrin is the main diagnostic criterion of medullary thyroid carcinoma, the results of the study correlate with the stage of the disease and tumor size. In 70% of patients, basal concentration of calcitonin is within 500-2000 pg/ml; in 30% - within normal limits or slightly exceeds normal values. After administration of pentagastrin, concentration of calcitonin increases in almost all patients with medullary thyroid cancer. If the basal level is initially elevated, then during the test with pentagastrin its concentration in blood increases by 10-20 times. In cases where the basal calcitonin level is at the lower limits of the norm or is not detectable, and after stimulation with pentagastrin it increases significantly, but does not go beyond the normal range, one should suspect an early stage of medullary cancer or hyperplasia of C-cells of the thyroid gland. In some patients, infusion of calcium preparations should be used as a stimulant, since tumors may not respond to pentagastrin.
A persistent increase in blood calcitonin levels after tumor removal in patients with medullary thyroid cancer may indicate that the surgery was not radical or that there are distant metastases. A rapid increase in calcitonin levels after surgery indicates a relapse of the disease.
An increase in the concentration of calcitonin in the blood is possible in non-malignant lung diseases, acute pancreatitis, hyperparathyroidism, pernicious anemia, Paget's disease. An increase in the concentration of calcitonin is also observed in malignant neoplasms of the mammary gland, stomach (most often in Zollinger-Ellison syndrome ), kidneys, and liver.
[