Magnesium has been referred to as "the forgotten electrolyte". Like sodium, potassium, and calcium, magnesium becomes a positively charged ion (cation) in the body, where it is responsible for enabling and regulating muscular function. Magnesium is the fourth most abundant cation in the body, and is found in every tissue in the body.
Magnesium citrate is a form of magnesium often taken in supplement form. Magnesium citrate is a salt, an ionic compound, that contains positive magnesium ions and negative citrate ions — the same negative ions that form citric acid when combined with positive hydrogen ions.
The name is ambiguous and may refer to salts that have these ions in a 1:1 ratio, a 3:2 ratio, or other ratios. Magnesium citrate is formed by combining magnesium oxide with citric acid, a reaction that creates magnesium citrate and water.
Magnesium citrate dissolves readily in water, so it may be used in powder, capsule, or liquid form. This also makes it an excellent source of dietary magnesium which absorbs readily into the bloodstream and bodily tissues.
Magnesium citrate is a good source of magnesium ions that are needed throughout the body. Magnesium is needed in every tissue in the body. It works with nucleic acids to produce energy, and it is involved in more than 300 enzyme systems that regulate protein production, signal transmission in nerves and muscles, blood pressure, blood glucose, and other functions.
The health benefits of magnesium citrate include:
Magnesium citrate causes the intestines to release water into the stool. This softens the stool and relieves constipation and irregularity. Magnesium citrate is more gentle than some of the other magnesium compounds and found as the active ingredient in many commercially available laxatives.
Muscle and Nerve Support
Magnesium is needed in order for muscles and nerves to function properly. Magnesium ions, along with calcium and potassium ions, provide the electrical charges that cause muscles to contract and that allow nerves to send electrical signals throughout the body.
Magnesium citrate helps to regulate the transport of calcium across cell membranes, playing a key role in bone creation. The bones are also a reservoir that stores magnesium for the body. Approximately 60% of the body's total magnesium is in the bones.
Magnesium helps to keep the heartbeat regular, by regulating conduction of the electrical signals that control the heart's timing. Magnesium citrate is commonly used to prevent arrhythmia. Arterial stiffness is a risk factor related to atherosclerosis that can cause cardiovascular problems. Magnesium citrate helps to make the artery walls more flexible, reducing this risk.
It is estimated that half of the U.S. population does not get enough magnesium in their diets. This is surprising, as magnesium should be available in vegetables and other food sources. One explanation suggests that soils may have become depleted of magnesium, producing crops and vegetables that are also depleted.
Magnesium deficiency can cause the following problems:
Under normal conditions for healthy individuals, excessive intake of magnesium citrate does not pose a health risk because the kidneys remove excess magnesium from the bloodstream.
Some people may experience diarrhea, nausea, and abdominal cramping when taking magnesium citrate supplements. If this happens, discontinue or reduce your dosage until these symptoms disappear.
However, long-term use at very high doses (such as the dosages used for laxatives and antacids, which may be as high as 5,000 mg/day) may cause magnesium toxicity. Symptoms of magnesium toxicity include:
Do not take magnesium-based laxatives or antacids for more than once per week without consulting with your doctor.
Amounts and Dosage
The Recommended Dietary Allowance (RDA) for magnesium is 400-420 milligrams (mg) per day for adult men, and 310-320 mg per day for adult women. Women who are pregnant may increase this amount to 350-360 mg per day.
A normal diet will provide most of the RDA for magnesium, so most brands only recommend taking 250 mg/day as a supplement. Take capsules or tablets with a full 8 ounce glass of water and with a regular meal.
However, higher doses may be suggested if you are using magnesium citrate as a laxative or as an antacid. Follow the label directions, and do not use it as a laxative or antacid for more than 1 week without consulting a doctor.
Magnesium is readily available from food, and can be obtained from leafy vegetables, nuts, seeds, and whole grains. An easy way to remember this is to associate magnesium with fiber. In most cases, foods that are good sources of fiber are also high in magnesium.
As with all supplements, you should check with your doctor if you are considering adding magnesium citrate supplements to your diet.