From the Guidelines
Daily calcium and vitamin D supplementation are recommended for all adults with hypocalcemia, particularly those with 22q11.2DS, to prevent complications such as fatigue, emotional irritability, and osteopenia/osteoporosis. Hypocalcemia is a condition characterized by abnormally low calcium levels in the blood, typically defined as a serum calcium level below 8.5 mg/dL or an ionized calcium level below 4.5 mg/dL 1. Treatment depends on the severity and underlying cause, with the goal of preventing complications and improving quality of life.
Key Considerations
- Regular investigations including measurements of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine concentrations are recommended to monitor hypocalcemia and its associated conditions 1.
- Magnesium supplementation is indicated for those with hypomagnesemia, as it can cause refractory hypocalcemia 1.
- Treatment with hormonally active metabolites of vitamin D may be necessary for more severe hypocalcemia, but usually requires consultation with an endocrinologist 1.
- Targeted monitoring of calcium concentrations should be considered at vulnerable times, such as peri-operatively, perinatally, or during severe illness, to prevent complications 1.
Management
- Calcium homeostasis is primarily regulated by parathyroid hormone, vitamin D, and calcitonin, which control calcium absorption, bone resorption, and renal excretion to maintain normal serum levels essential for nerve conduction, muscle contraction, blood coagulation, and cellular signaling.
- Standard treatments for hypocalcemia, such as calcium and vitamin D supplementation, seem effective in managing the condition and preventing complications 1.
- Routine clinical monitoring for autoimmune thyroid disease is also indicated, as more than 1 in 4 adults with 22q11.2DS may develop hypothyroidism, and 1 in 20 has hyperthyroidism 1.
From the Research
Definition and Causes of Hypocalcemia
- Hypocalcemia is a condition characterized by low serum calcium levels, which can be life-threatening if severe 2.
- It can occur in conjunction with multiple disorders, including hypoparathyroidism and disorders that disrupt vitamin D metabolism 2.
- Bisphosphonate treatment can also induce hypocalcemia, especially in patients with underlying vitamin D deficiency or renal dysfunction 3, 4, 5.
Symptoms and Diagnosis of Hypocalcemia
- Symptoms of acute hypocalcemia include neuromuscular irritability, tetany, and seizures, which can be rapidly resolved with intravenous administration of calcium gluconate 2.
- Chronic hypocalcemia often has more subtle manifestations, and diagnosis requires knowledge of the factors that influence calcium homeostasis 2.
- Assessment of calcium status can be inconsistent, and adjusted calcium (AdjCa) may not be a good surrogate of ionized calcium (iCa) in critically ill patients 6.
Treatment and Management of Hypocalcemia
- Treatment options for hypocalcemia vary depending on the underlying disorder, and may include calcium and vitamin D supplementation 2.
- In patients with hypoparathyroidism, calcium and vitamin D supplementation must be carefully titrated to avoid symptoms of hypocalcemia and hypercalciuria 2.
- Calcium replacement may not improve normalization or mortality in critically ill patients with hypocalcemia, and its use should be carefully considered 6.
- Evaluation of renal dysfunction, vitamin D deficiency, and parathyroid gland dysfunction is necessary before bisphosphonate treatment, and accurate monitoring of plasma calcium and creatinine levels is mandatory 3, 4, 5.