Hypokalciemi

Hypokalciemi, also known as hypocalcemia, is a condition characterized by low levels of calcium in the blood. Calcium is essential for bone formation, muscle function, nerve signaling, and blood clotting. Normal regulation involves the parathyroid hormone, vitamin D, calcitonin, the kidneys, and bone turnover. Total serum calcium can be influenced by albumin levels; ionized calcium is the physiologically active fraction.

Clinical presentation ranges from none to severe. Mild cases may cause numbness, tingling in lips and fingers, or muscle cramps. More significant deficiency can lead to tetany, facial muscle twitching, seizures, and potentially life-threatening cardiac arrhythmias. Signs such as Chvostek’s or Trousseau’s may be observed on examination.

Causes are diverse. Hypoparathyroidism (including after neck surgery) is a common cause, as are vitamin D deficiency and malabsorption. Chronic kidney disease can impair calcium and vitamin D metabolism. Other contributors include pancreatitis, hyperphosphatemia, magnesium deficiency, certain medications (for example, bisphosphonates, anticonvulsants, or loop diuretics), and, in some cases, acute illness or critical illness. Hypoalbuminemia can lower measured total calcium without affecting ionized calcium.

Diagnosis involves measuring total and/or ionized calcium, often with albumin adjustment. Evaluation usually includes parathyroid hormone, magnesium, phosphate, and vitamin D levels, as well as assessment of kidney function and dietary intake.

Treatment depends on severity and cause. Mild cases may require dietary calcium and vitamin D supplementation, or monitoring. Acute or symptomatic hypocalcemia is treated with calcium, typically calcium gluconate given intravenously, followed by oral calcium with active vitamin D (calcitriol) if needed. Correcting coexisting magnesium deficiency is important, and the underlying cause should be addressed to prevent recurrence.