Calcium is an extremely vital mineral required by the body to maintain adequate strength of bones and teeth as well blood pressure regulation. There are certain situations or conditions where the body does not get enough calcium resulting in depleted calcium levels in the body. Low blood calcium level (Hypocalcemia) results in various medical complications. The medical condition where there is a deficiency of calcium in the body is called as Hypocalcemia. In this article, we will read in detail the various causes, symptoms and treatments of Hypocalcemia.
How Do We Define Hypocalcemia?
- Calcium, as stated, is an extremely important mineral in the body, which strengthens the bones and regulates the blood pressure.
- Decreased calcium intake in diet can cause Osteoporosis or Hypocalcemia.
- Hypocalcemia is congenital disease and may or may not be associated with hypoparathyroidism.1
- Majority of calcium is stored in bones. Elderly individuals are exposed to aging process of entire body and subject to wear and tear of bone mineral deposits, which is calcium. The decreased intake of calcium and increased metabolic demineralization of calcium in bone results in increased excretion of calcium and causes Hypocalcemia.
- The bones become fragile due to decreased level of calcium (Hypocalcemia) and often show signs of osteoporosis.
- Abnormal calcium metabolism and demineralization of the bone is often caused by hormonal changes in menopausal female resulting in osteoporosis.
Causes Of Hypocalcemia
- Hereditary Disease-
- Autosomal Dominant Hypocalcemia- Severe Hypocalcemia is observed in Bartter's syndrome.1
- Genetic Mutation- Hypocalcemia is congenital disease caused by genetic mutation of calcium sensing receptor (CASR) gene.1
- Increased Excretion of Calcium-
- Ageing Disease- Hypocalcemia can be caused as a result of natural aging process where the levels of calcium start to decrease in the body with age as excretion of calcium is more than absorption of calcium.
- Hypoparathyroid Disease- Hypocalcemia is caused by decreased absorption of calcium influenced by low parathyroid hormone. Thyroidectomy often is associated with low parathyroid hormone secretion because of removal of parathyroid gland during thyroidectomy surgery.2
- Vitamin D Deficiency- Vitamin D deficiency is associated with Hypocalcemia.
- Hypermagnesemia- Increased level of magnesium interferes with calcium absorption in blood and calcium deposits in bones.
- Decreased Absorption of Calcium-
- End stage renal disease
- Chelation- use of citrate and lactate
- Babies born to mothers who are diabetic also have a risk to develop hypocalcemia.
- Some of the other causes of Hypocalcemia are malnutrition and malabsorption.
Symptoms Of Hypocalcemia
Nonspecific Symptoms of Hypocalcemia-
- Drowsy and sleepiness
Specific Symptoms of Hypocalcemia-
- Musculoskeletal System
- Muscle spasm
- Hyperactive tendon reflex
- Latent tetany
- Trousseau Sign- Maintaining pressure within blood pressure cuff above systolic pressure causes severe muscle spasm in same arm known as carpal spasm.
- Chvostek’s Sign- The test is performed by neurologist. Facial bone zygoma is palpated and tapped with index finger, which results in facial spasm.
- Nervous System
- Cognitive dysfunction
- Sensory dysfunction-
- Numbness and tingling in the extremities and face
- Respiratory System-
- Cardio-Vascular System-
- Petechiae- mostly observed over extremities.
- Bruises or Purpura- seen over trunks and extremities.
Diagnosis of Hypocalcemia
- Blood Electrolytes-
- Low serum ionized calcium level (level below 4.4mg/dL).
- Pancreatic Enzyme-
- Amylase elevated suggesting pancreatitis
- Hyper or hypomagnesemia-
- Blood serum level of magnesium is either low or elevated.
- Kidney Function Test-
- Serum creatinine and BUN are elevated suggesting kidney failure
- Parathyroid Hormone (PTH) Study-
- iPTH level is low
- Vitamin D Level-
- 25- hydroxyvitamine D and 1,25-hydroxyvitamin D level is low
Arrhythmias Observed Over ECG Are As Follows-
- QT- prolongation
- Ventricular fibrillation
- Ventricular tachycardia4
Treatment For Hypocalcemia
- Oral Calcium-
- Calcium level lower than 7 mg/L is treated with intravenous calcium. Calcium level above 7 mg/L is treated with oral calcium and diet.
- Calcium diet and pills- Calcium supplement diet and over the counter pills with vitamin D is prescribed.5
- Intravenous Calcium-
- Calcium level lower than 7 mg/L is treated with intravenous calcium.
- Intravenous calcium is injected as chloride or gluconate.
- Calcium gluconate 10% is prescribed for severe Hypocalcemia.
- Calcium gluconate is preferred over calcium chloride since it causes less tissue damage if accidently injected in surrounding soft tissue.
- Intravenous Magnesium-
- Hypomagnesemia is treated with intravenous magnesium. 2 gm magnesium is injected over 30 minutes.
- Oral Vitamin D-
- Several over the counter vitamin D pills are available.
- The vitamin D dosage and how long should the pills be taken should be discussed with physician.
- Frequent blood examination and diagnosis of cause of Hypocalcemia will dictate the length of treatment.
- Vitamin D with calcium is beneficial in treating Hypocalcemia when caused by low parathyroid hormone.5
Complications Of Hypocalcemia
Some Of The Complications Of Hypocalcemia Are
- Fragile bones
- Eye dysfunction
- Abnormal heartbeat
1. Functional activities of mutant calcium-sensing receptors determine clinical presentations in patients with autosomal dominant hypocalcemia.
Kinoshita Y1, Hori M, Taguchi M, Watanabe S, Fukumoto S.
J Clin Endocrinol Metab. 2014 Feb;99(2):E363-8. doi: 10.1210/jc.2013-3430. Epub 2013 Dec 2.
2. Vitamin D deficiency and the risk of hypocalcemia following total thyroidectomy.
Nhan C1, Dolev Y, Mijovic T, Rivera JA, Kallai-Sanfaçon MA, Mlynarek AM, Payne RJ
J Otolaryngol Head Neck Surg. 2012 Dec;41(6):401-6.
3. Reading epilepsy as the initial symptom of idiopathic hypoparathyroidism.
Maeda K1, Sekine O.
Intern Med. 2011;50(11):1235-7
4. Potential benefit of oral calcium/vitamin D administration for prevention of symptomatic hypocalcemia after total thyroidectomy.
Kurukahvecioglu O1, Karamercan A, Akin M, Tezel E, Ege B, Taneri F, Onuk E.
Endocr Regul. 2007 Mar;41(1):35-9.
5. Hypocalcemic myocardial dysfunction: short- and long-term improvement with calcium replacement.
Wong CK1, Lau CP, Cheng CH, Leung WH, Freedman B.
Am Heart J. 1990 Aug;120(2):381-6.