calcitonintasojen

Calcitonin is a peptide hormone produced by the parafollicular C cells of the thyroid gland. It helps regulate calcium and phosphate balance, and in humans its physiological role is less critical than that of parathyroid hormone and vitamin D. The term calcitonin levels refers to the concentration of this hormone in the blood at a given time.

Calcitonin is measured in serum using immunoassays. Results are usually reported in picograms per milliliter (pg/mL) or nanograms per liter (ng/L), depending on the laboratory. Reference ranges vary by assay, age, sex, and smoking status, and different laboratories may use different cutoffs. Basal levels are typically very low in healthy adults.

Normal ranges are often below 10 pg/mL in many adults, but values can be higher in older individuals or due to assay differences. Interpretation should consider the clinical context.

In endocrinology, basal serum calcitonin serves as a tumor marker for medullary thyroid carcinoma (MTC), arising from C cells. Significantly elevated calcitonin can indicate MTC or C-cell hyperplasia; mild elevations require further assessment for other conditions, including neuroendocrine tumors or chronic kidney disease. Calcitonin levels are also used in postoperative surveillance for MTC and, in some cases, to screen nodular thyroid disease for possible MTC.

Not all increases indicate cancer; factors such as smoking and kidney function can influence levels; assay variability can cause false positives; we often rely on imaging and cytology in combination with calcitonin testing. Some older stimulation tests used pentagastrin to provoke calcitonin release; these are less common now due to invasiveness and patient tolerance. Overall, calcitonin levels are a useful but specialized measure in calcium homeostasis and thyroid cancer management.