Fast Five Quiz: Common Nutritional Deficiencies

Romesh Khardori, MD, PhD


February 26, 2019

Acute hypocalcemia may lead to syncope, congestive heart failure, and angina owing to multiple cardiovascular effects. Neuromuscular and neurologic symptoms may also occur. Neuromuscular symptoms include the following:

  • Numbness and tingling sensations in the perioral area or in the fingers and toes

  • Muscle cramps, particularly in the back and lower extremities; may progress to carpopedal spasm (ie, tetany)

  • Wheezing; may develop from bronchospasm

  • Dysphagia

  • Voice changes (due to laryngospasm)

Neurologic symptoms of hypocalcemia include the following:

  • Irritability, impaired intellectual capacity, depression, and personality changes

  • Fatigue

  • Seizures (eg, grand mal, petit mal, focal)

  • Other uncontrolled movements

In order of frequency, hypocalcemia occurs in the following settings:

  • Chronic and acute renal failure

  • Vitamin D deficiency

  • Magnesium deficiency

  • Acute pancreatitis

  • Hypoparathyroidism and pseudohypoparathyroidism

  • Infusion of phosphate, citrate, or calcium-free albumin

Ionized calcium measurement is the definitive method for diagnosing hypocalcemia. A serum calcium level < 8.5 mg/dL or an ionized calcium level < 18 mg/dL is considered hypocalcemia. The PTH level should also be checked as early as possible. This test is an antibody-mediated radioimmunoassay. Low to normal PTH levels occur in patients with hereditary or acquired hypoparathyroidism and in patients with severe hypomagnesemia. Patients with ineffective PTH have elevated PTH levels. The PTH elevation is a result of hypocalcemia.

Treatment of chronic hypocalcemia depends on the cause of the disorder. Patients with hypoparathyroidism and pseudohypoparathyroidism can be managed initially with oral calcium supplements. The hypercalcemic effects of thiazide diuretics may offer some additional benefits. In patients with severe hypoparathyroidism, vitamin D treatment may be required; however, remember that PTH deficiency impairs the conversion of vitamin D to calcitriol. Therefore, the most efficient treatment is the addition of 0.5-2 µg of calcitriol or 1-alpha-hydroxyvitamin D3. Parathyroidectomy (subtotal or total) may be indicated in certain patients with severe secondary hyperparathyroidism and renal osteodystrophy.

Read more about hypocalcemia.


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