Calciumspiegels

Calciumspiegels refers to the concentration of calcium in the blood, most commonly measured as serum calcium. The laboratory measurement can report total calcium or the fraction that is ionized (free calcium). Ionized calcium is physiologically active.

Normal total serum calcium typically lies about 2.2–2.6 mmol/L (8.8–10.3 mg/dL), while ionized calcium is about 1.1–1.3 mmol/L (4.5–5.2 mg/dL). Values may vary by assay and by the presence of hypoalbuminemia, which lowers total calcium without changing ionized calcium. Corrected calcium accounts for albumin.

Calcium homeostasis is regulated by parathyroid hormone (PTH), vitamin D, and calcitonin. PTH raises calcium by promoting bone resorption, increasing kidney reabsorption, and stimulating active vitamin D production, which enhances intestinal calcium absorption. Calcitonin and, to a lesser extent, high phosphate lower calcium.

Abnormal calciumspiegels can reflect endocrine disorders, kidney disease, or malignancy. Hypercalcemia (elevated calcium) may cause fatigue, thirst, polyuria, constipation, neuromuscular symptoms, and, if severe, arrhythmias. Causes include primary hyperparathyroidism, malignancy with bone involvement, granulomatous diseases, and certain medications.

Hypocalcemia (low calcium) can cause tingling, muscle cramps, seizures, or cardiac effects; common causes include hypoparathyroidism, vitamin D deficiency, chronic kidney disease, or acute pancreatitis. Assessment typically includes serum calcium with albumin, PTH level if abnormal, and measurement of ionized calcium when precise calcium activity is needed. Treatment targets the underlying cause and may involve calcium supplementation or restriction, vitamin D, and, in emergencies, intravenous calcium or other targeted therapies.