What are the causes of hypocalcemia in a 54-year-old male?

From the Guidelines

Low calcium levels (hypocalcemia) in a 54-year-old male are most commonly caused by vitamin D deficiency, hypoparathyroidism, or chronic kidney disease, which can lead to increased mortality, incidence of fractures, and decreased quality of life 1. The causes of hypocalcemia can be multifactorial, including:

• Vitamin D deficiency, which impairs calcium absorption from the intestines
• Hypoparathyroidism, where the parathyroid glands don't produce enough parathyroid hormone to regulate calcium
• Chronic kidney disease, which affects vitamin D activation
• Certain medications like bisphosphonates, anticonvulsants, or proton pump inhibitors
• Magnesium deficiency
• Pancreatitis
• Surgical removal of the parathyroid glands Other potential causes include malabsorption syndromes, certain cancers, or genetic disorders. According to the study by 1, secondary hyperparathyroidism (SHPT) is a failure of calcium homeostasis whereby increased PTH production in response to hypocalcemia (and/or hyperphosphatemia) is unable to correct plasma calcium because of organ failure or reduced calcium availability. Treatment of hypocalcemia should prioritize addressing the underlying cause, and may include calcium supplements (typically 1000-1500mg daily of elemental calcium) and vitamin D supplements (800-1000 IU daily of vitamin D3) 1. It is essential to note that severe hypocalcemia may require immediate intravenous calcium gluconate, and a comprehensive evaluation by a healthcare provider is necessary to determine the specific cause and appropriate treatment plan. The relationship between serum calcium levels and mineralization surface, osteoid surface, and cortical/total bone area has been studied, and a positive relationship has been found between serum calcium level and mineralization surface and osteoid surface 1. However, the study by 1 suggests that the pathogenesis of hypocalcemia in chronic kidney disease is complex and multifactorial, involving phosphate retention, skeletal resistance to the calcemic action of PTH, and altered vitamin D metabolism.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Causes of Low Calcium in Males

• Hypoparathyroidism is a rare endocrine disorder characterized by hypocalcemia and low or undetectable levels of parathyroid hormone 2
• Removal of, or damage to, the parathyroid glands at the time of anterior neck surgery is the most likely etiology of hypoparathyroidism 2
• Autoimmune destruction of the parathyroid glands and other genetic causes also represent common etiologies of hypoparathyroidism 2
• Hypocalcemia can also be caused by non-PTH mediated disorders, which require a comprehensive search for other causes for appropriate treatment 3
• Other causes of hypocalcemia include postsurgical hypoparathyroidism, autoimmune disease, genetic causes, infiltrative diseases, mineral deposition, or abnormalities in serum levels of magnesium 4

Pathophysiology of Low Calcium

• In hypoparathyroidism, the kidneys lose the calcium-conserving actions of parathyroid hormone and excrete a greater fraction of calcium, leading to hypocalcemia 2, 5
• The lack of parathyroid hormone action on the kidney results in deregulation of renal mechanisms transporting calcium and phosphate reabsorption, leading to hypocalcemia and hyperphosphatemia 5
• Hypocalcemia can cause neuromuscular disturbances ranging from epilepsy and tetany to mild paresthesia, and hyperphosphatemia can promote ectopic mineralization disease 5

Diagnosis and Management of Low Calcium

• The diagnosis of hypocalcemia involves measuring serum calcium levels, and the management involves treating the underlying cause 3
• Conventional treatment of hypoparathyroidism consists of oral calcium salts and active vitamin D, but it has limitations and can increase the risk of long-term complications 2, 4
• PTH replacement therapy, such as recombinant human PTH(1-84) or palopegteriparatide, can effectively achieve normal serum levels of calcium and lower serum levels of phosphate, and reduce the pill burden 3, 4