Your body contains more calcium than any other mineral. Even though 99 percent of your calcium is stored in your bones and teeth, the small amount in your circulation plays a vital role in maintaining optimal function of your muscles, nerves and heart. In fact, calcium is so important to these tissues that your body will extract it from your bones to maintain constant serum calcium levels. Calcium deficiency is sometimes associated with heart enlargement and congestive heart failure.
Calcium’s Role
Calcium is a key participant in generating the electrical currents that allow your heart and muscles to contract and your nerves to conduct messages. Calcium’s movement across cell membranes is a necessary part of these processes. In addition, your heart and muscles are laden with small, sac-like vesicles filled with calcium. When stimulated, these vesicles release a flood of calcium that binds to proteins that trigger muscular contractions. Almost instantaneously, the calcium is then pumped back into the vesicles to await the next contraction cycle. Without sufficient calcium stores, your heart and muscles contract poorly and lose their tone.
Hypocalcemia
Calcium deficiency, or hypocalcemia, can be due to a number of causes. Vitamin D deficiency, decreased parathyroid hormone secretion due to diseased or damaged parathyroid glands, kidney disease, magnesium deficiency and high serum phosphate levels can all contribute to hypocalcemia. Mild hypocalcemia does not usually cause any symptoms, but more severe cases can cause muscle weakness and cramps, depression, dementia, psychosis, muscle spasms, abnormal sensations in your hands, feet, lips and tongue, seizures, heart failure and cardiomegaly, or heart enlargement.
Heart Enlargement
Rickets, a disease characterized by vitamin D deficiency and hypocalcemia, is unusual in developed countries due to widespread fortification of foods with vitamin D. However, in many areas, rickets is still an important health problem, particularly among infants and children. In rare instances, hypocalcemia can cause dilated cardiomyopathy – congestive heart failure and enlarged heart – in children or adults. An August 2009 review in “Pediatric Cardiology” described four black infants who developed dilated cardiomyopathy due to rickets, and the October 2004 issue of “Echocardiography” reported a case of dilated cardiomyopathy in a 40-year-old woman who became hypocalcemic when her parathyroid glands were damaged during thyroid surgery. All of these patients improved after supplementation with calcium and vitamin D.
Considerations
Your calcium status is a major determinant of your heart’s health. In rare cases, calcium deficiency – whether due to vitamin D deficiency or any other cause – can lead to heart enlargement and decreased cardiac function. Recommended dietary allowances for calcium vary from 200 mg daily for infants to 1,300 mg for adolescents, pregnant women and nursing mothers. Adequate vitamin D intake is also important for maintaining adequate serum calcium levels. Dietary recommendations for this vital nutrient range from 400 IU daily for infants to 800 IU for elderly adults. Ask your doctor if your calcium and vitamin D requirements are being met.
References
- Linus Pauling Institute at Oregon State University: Calcium
- “Echocardiography”; A Rare Cause of Dilated Cardiomyopathy: Hypocalcemia; A. Avsar, et al.; October 2004
- “The Merck Manual of Diagnosis and Therapy, 18th Edition: Hypocalcemia”; Mark H. Beers, M.D., Editor-in-Chief; 2006
- “Pediatric Cardiology”; Hypocalcemic Rickets and Dilated Cardiomyopathy: Case Reports and Review of Literature; J. Brown, et al.; August 2009
- Linus Pauling Institute at Oregon State University: Vitamin D
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