One of the many roles of magnesium in the body is in regulating muscle contraction and relaxation, so too much of the mineral can cause noticeable effects in the muscles. Excess magnesium levels typically occur when people take supplements of the mineral to treat a medical condition, not because of high dietary intake. Because of potentially life-threatening risks, you should not take supplemental magnesium unless under the care of a doctor.
Uses of Magnesium Supplements
Most people get enough magnesium from the foods they eat. However, some people have medical conditions that may contribute to deficiencies of the mineral and they may need a supplement. In addition, pharmacological doses of magnesium sometimes are prescribed to treat medical conditions such as high blood pressure, heart disease and diabetes, the Linus Pauling Institute reports. Because high doses of magnesium can affect muscle function and contribute to other complications, discuss its use with a doctor.
Upper Intake Limits
At the levels consumed in foods, magnesium poses no risk of toxicity. To help prevent too much of the mineral from accumulating because of supplemental use, the federal government has established tolerable upper intake levels. How much you can safely consume depends on your age. For kids and adults 9 and older, the upper intake limit is 350 mg per day. For younger kids ages 4 to 8, it is 110 mg per day, while kids ages 1 to 3 should consume no more than 65 mg per day, the National Institutes of Health Office of Dietary Supplements reports. No upper intake limit has been determined for infants.
Effects on Muscles
Both too much and too little magnesium in the body can affect your body's muscles. In the case of magnesium toxicity, you may experience weakness in the muscles, the Office of Dietary Supplements reports. However, muscle weakness and related lethargy typically occur in cases of severe toxicity. A magnesium deficiency can also cause problems with the muscles. Early on, you may notice muscle twitching. As the deficiency worsens, the twitching can turn into more severe muscle contractions, according to Medline Plus, an NIH online medial encyclopedia.
Signs of Magnesium Toxicity
Often, the first sign of too much magnesium is diarrhea. It can also cause low blood pressure and abdominal cramping. Then, as the levels become higher, people can become mentally confused and begin to experience heart disturbances and difficulty breathing, the Linus Pauling Institute reports. Once it reaches a critical level -- after the respiratory, gastrointestinal and muscle system become affected -- you can go into cardiac arrest and die.
Member Comments