Side Effect: Low Blood Calcium (hypocalcemia)

What is Low Blood Calcium (hypocalcemia)?

Calcium is an essential mineral that plays a critical role in various physiological functions such as bone health, muscle contraction, nerve function, and blood clotting.

• A low blood calcium level, also known as hypocalcemia, is a condition where there is an abnormally low level of calcium in the blood.
• Calcium levels below 8.5 mg/dL (2.1 mmol/L) or ionized calcium levels below 4.5 mg/dL (1.1 mmol/L) are considered to be too low and may lead to symptoms that you can see and feel.

What does Low Blood Calcium (hypocalcemia) look like?

Patients with mild hypocalcemia often do not experience any symptoms, but symptoms that can occur include muscle cramps, muscle twitching, depression, or confusion. More severe cases may be life threatening and can cause seizures, muscle spasms, coma, or cardiac arrhythmias.

Who gets Low Blood Calcium (hypocalcemia)?

Hypocalcemia can be caused by a variety of factors in patients with cancer:

• Poor nutrition
• Decreased parathyroid hormone (PTH)
• Vitamin D deficiency
• Chemotherapy
• Decreased absorption due to tumor in the bowel
• Decreased absorption after bowel surgery
• Treatment with bone modifying agents such as denosumab (Xgeva®, Prolia®), zoledronic acid (Zometa®), or pamidronate (Aredia®)
• Liver dysfunction
• Tumor lysis syndrome
• Concomitant diseases such as renal failure, sepsis, and pancreatitis
• Patients receiving citrate anticoagulant during hemodialysis or apheresis when collecting stem cells

How to prevent Low Blood Calcium (hypocalcemia)

Prevention of hypocalcemia in cancer patients involves regular monitoring of calcium levels and identifying and addressing any possible risk factors. Some patients may need to be started on preventative calcium supplementation. For example, vitamin D supplementation may be recommended for patients with vitamin D deficiency, while treatment of low parathyroid may involve calcium and vitamin D supplementation.

How to treat Low Blood Calcium (hypocalcemia)

Treatment of hypocalcemia in patients with cancer depends upon the severity of the condition.

• Mild hypocalcemia can often be managed with oral calcium and vitamin D supplementation alone
• Severe hypocalcemia may require intravenous calcium administration.
• In some cases, the underlying cause of hypocalcemia may need to be treated before calcium levels can be restored to normal.