Known as the silent killer, high blood pressure is a condition that affects one in three American adults, often without any warning, according to the National Heart Lung and Blood Institute. While doctors cannot always pinpoint the cause of high blood pressure, research shows calcium plays an important role in your risk of developing the condition.
High Blood Pressure
High blood pressure, also known as hypertension, is a serious condition that occurs when an abnormally high force of blood pushes against your artery walls as your heart pumps blood. While the condition often causes no symptoms, left uncontrolled, high blood pressure can lead to stroke, heart attack, heart failure, kidney damage and sudden cardiac death. A blood pressure reading of 140/90 millimeters of mercury, or mmHg, and above, is considered high for most adults. High blood pressure can develop gradually over time with no known cause or occur due to certain medications or an underlying medical condition such as kidney or hormonal disorders. Other risk factors include age, race, obesity, a family history of high blood pressure, and alcohol and tobacco use.
Role of Calcium
Calcium is an important mineral necessary for building and maintaining strong bones and teeth. Your body also needs calcium for blood clotting, normal heart rhythm, and nerve and muscle function. Research shows people with low levels of calcium are at greater risk of developing high blood pressure, the University of Maryland Medical Center reports. Some studies suggest increasing calcium levels can help reduce high blood pressure, yet scientific findings remain inconclusive.
Calcium Supplements
Taking calcium supplements can lower blood pressure by up to 2 mmHg in those with or without high blood pressure, according to MedlinePlus. The results are even more beneficial in people with low levels of calcium. For women at risk of pre-eclampsia --- high blood pressure during pregnancy --- research finds that taking up to 2 g of calcium daily reduces the chance of developing hypertension by 50 percent, MedlinePlus reports.
High Blood Pressure Medications
In high amounts, calcium supplements are known to interfere with certain high blood pressure medications, making the medications less effective in controlling hypertension. These include thiazide diuretics, also known as water pills, and calcium channel blockers. Taking 1,500 mg or more of calcium with thiazide diuretics can cause a condition known as milk-alkali syndrome, which results in dangerously high blood levels of calcium, MayoClinic.com reports. High levels of calcium can lead to high blood pressure and kidney failure. Similarly, receiving calcium through an intravenous line may reduce the effectiveness of calcium channel blockers, a medication that helps relax and widen blood vessel walls to lower blood pressure.
Excess Calcium
A growing body of scientific evidence suggests taking calcium supplements may impact your likelihood of heart attack and stroke. According to an analysis of scientific studies by Mark J. Bolland and colleagues in an April 2011 issue of the "British Medical Journal," taking calcium supplements with or without vitamin D may increase a person's risk of heart attack and stroke by 25 to 30 percent and 15 to 20 percent, respectively, particularly in older women. The authors suggest a sudden change in blood calcium levels after ingesting supplements may be to blame. High blood calcium levels are associated with hardening of the arteries, a condition that leads to high blood pressure. Until scientific research can conclusively confirm the findings, do not consume more than 1,000 to 1,200 mg of calcium daily, MedlinePlus advises.
References
- National Heart Lung and Blood Institute: High Blood Pressure
- University of Maryland Medical Center; Calcium; March 2009
- MedlinePlus; Calcium; June 2011
- MayoClinic.com; Calcium Supplements --- Do They Interfere With Blood Pressure Drugs?; Sheldon G. Sheps; June 2010
- "British Medical Journal"; Calcium Supplements With or Without Vitamin D and Risk of Cardiovascular Events --- Re-analysis of The Women's Health Initiative Limited Access Dataset and Meta-Analysis; Mark J. Bolland, et al.; April 2011
- "The Merck Manual Home Health Handbook"; Robert S. Porter, et al.; 2009
