Can a Magnesium Deficiency Cause a Rapid Heart Rate?

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Magnesium is a macromineral, which means your body requires large amounts of it compared to trace minerals. All of your organs, particularly your heart, need magnesium. Magnesium carries an electrical charge, so it is in a class of elements known as electrolytes. Magnesium deficiency can cause rapid heartbeat, nausea, vomiting and agitation.


Your body uses magnesium as a cofactor for more than 300 chemical reactions. Magnesium contributes to bone health. It plays a role in helping your body absorb and use calcium. Half of your body's total magnesium content is found in your bones. It is also important to smooth muscle and nerve function. It helps promote healthy heart rhythm and plays a role in energy production. It also helps promote healthy blood pressure and supports immune function.

Magnesium and Heart Health

Cations are ions that carry a positive electrical charge. Magnesium and potassium are the most abundant cations in your body. Cations play an important role in regulating your heartbeat. A normal heart rate at rest is between 60 and 100 beats per minute. You are considered to have a rapid heartbeat if your heart rate is above 100 beats per minute at rest. This is also known as tachycardia. Restoring magnesium helps bring your rate into the normal range if magnesium deficiency is the cause.


Magnesium is abundant in your diet. For this reason, a true magnesium deficiency is uncommon. However, certain conditions, such as kidney disease, severe diarrhea or vomiting, can cause excess magnesium loss. Severe magnesium deficiency can be dangerous. It can cause seizures and extremely low blood pressure. In these instances it is treated promptly through intravenous replacement. You may experience muscle spasms, fatigue and insomnia in milder deficiency states.

Sources and Supplements

Bananas, green leafy vegetables, whole grains, wheat bran and legumes are magnesium sources. The recommended dietary intake is 400 mg daily if you are a man under 30 and 310 mg for women under 30. Men and women over 30 should get about 20 mg more. Magnesium supplements are available in capsule, tablet and powder form. Side effects include upset stomach and diarrhea. A typical dose does not exceed the recommended dietary intakes. Consult your doctor before taking magnesium supplements.