Electrolytes: Calcium Disorders.

Area of Science:

• Endocrinology
• Internal Medicine
• Oncology

Background:

• Normal serum calcium levels range from 8 to 10 mg/dL.
• Hypercalcemia is defined as calcium levels of 10.5 mg/dL or greater, requiring confirmation with albumin-adjusted or ionized calcium.
• The most frequent etiologies of hypercalcemia are hyperparathyroidism and malignancy, though certain medications like lithium and thiazide diuretics can also contribute.

Purpose of the Study:

• To outline the diagnostic approach to hypercalcemia and hypocalcemia.
• To describe initial management strategies for hypercalcemia.
• To differentiate common causes of hypercalcemia based on parathyroid hormone levels.

Main Methods:

• Diagnosis confirmation using albumin-adjusted or ionized calcium levels.
• Initial treatment for severe or symptomatic hypercalcemia involves hydration.
• Evaluation includes parathyroid hormone (PTH) level assessment to guide etiology determination.

Main Results:

• Low PTH levels suggest malignancy (e.g., multiple myeloma, breast cancer, lymphoma) as the cause.
• Normal or elevated PTH levels indicate hyperparathyroidism as the likely cause.
• Hypocalcemia is frequently linked to vitamin D deficiency, with treatment involving intravenous calcium gluconate and magnesium repletion if necessary.

Conclusions:

• Hyperparathyroidism and malignancy are primary causes of hypercalcemia, distinguished by PTH levels.
• Management strategies for hypercalcemia range from hydration and monitoring to surgical intervention for hyperparathyroidism.
• Vitamin D deficiency is a common cause of hypocalcemia; while supplementation doesn't prevent fractures, it can reduce falls in at-risk older adults.