From the Guidelines
Hypocalcemia is primarily caused by vitamin D deficiency, hypoparathyroidism, chronic kidney disease, pancreatitis, and medication effects, and its diagnosis and treatment should prioritize addressing the underlying condition and correcting calcium levels to prevent morbidity and mortality. The most common causes of hypocalcemia include:
- Vitamin D deficiency, which impairs calcium absorption from the intestines 1
- Hypoparathyroidism, where the parathyroid glands produce insufficient parathyroid hormone (PTH) 1
- Chronic kidney disease, which reduces vitamin D activation 1
- Pancreatitis, which causes calcium deposition in inflamed tissues
- Medication effects from drugs like bisphosphonates or certain anticonvulsants Other causes include malabsorption syndromes that prevent calcium uptake, rapid blood transfusions with citrated blood products that bind calcium, and critical illness, particularly sepsis 1. Pseudohypocalcemia can occur with low albumin levels, as calcium binds to albumin in the blood 1. Understanding these causes is essential for proper diagnosis and treatment of hypocalcemia, which may include calcium supplementation, vitamin D therapy, and addressing the underlying condition 1. It is crucial to note that the treatment of hypocalcemia should be individualized, especially in patients with chronic kidney disease, to avoid the potential harm associated with a positive calcium balance 1. Regular investigations, including measurements of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine concentrations, are recommended to monitor and manage hypocalcemia effectively 1.
From the FDA Drug Label
7 DRUG INTERACTIONS
7.1 Cardiac Glycosides Hypercalcemia increases the risk of digoxin toxicity, while digoxin may be therapeutically ineffective in the presence of hypocalcemia.
The reason for hypocalcemia mentioned in the drug label is the potential ineffectiveness of digoxin in its presence.
- Hypocalcemia may occur due to the ineffectiveness of certain medications, such as digoxin, when calcium levels are low 2.
From the Research
Hypocalcemia Causes
- Hypoparathyroidism, characterized by impaired secretion of parathyroid hormone (PTH), is a classic cause of chronic hypocalcemia 3
- Disorders that disrupt the metabolism of vitamin D can also lead to chronic hypocalcemia, as vitamin D is responsible for increasing the gut absorption of dietary calcium 3
- Bisphosphonate treatment can cause hypocalcemia, especially in patients with vitamin D deficiency 4, 5
- Vitamin D deficiency is frequent in oncology patients with bone metastasis treated with bisphosphonates and might increase bone damage 6
Hypocalcemia Risk Factors
- Renal dysfunction can increase the risk of hypocalcemia, especially in patients treated with bisphosphonates 4, 5
- Poor oral intake, inadequate sunlight exposure, and renal failure can contribute to vitamin D deficiency, increasing the risk of hypocalcemia 4
- Hypocalcemia can be life-threatening if severe, and its symptoms can include neuromuscular irritability, tetany, and seizures 3
Hypocalcemia Treatment
- Intravenous calcium infusion is essential to raise calcium levels and resolve or minimize symptoms in the setting of acute hypocalcemia 7
- Oral calcium and/or vitamin D supplementation is the most frequently used treatment for chronic hypocalcemia 7
- Replacement of PTH in hypoparathyroidism, using recombinant human (rh) PTH(1-84), has been recently approved and can be effective in correcting serum calcium levels and reducing the daily requirements of calcium and active vitamin D supplements 7