Magnesium Deficiency, Restlessness & Migraines

Magnesium is a metallic mineral that is classified as a macromineral in human nutrition. This means you have to consume fairly large amounts -- milligrams as opposed to micrograms -- in order to maintain optimal levels in your tissues. Magnesium is involved in several hundred enzymatic reactions within your cells, and it helps to maintain the integrity of your bones and teeth. According to nutritionist Elson Haas, M.D., one of magnesium's most important functions is to regulate the activity of your nerves and muscles, a function that may play a role in migraines, insomnia, anxiety, restlessness and other conditions.

Measurement

Most of the ionized magnesium in your body is found inside your cells. Therefore, measurement of your plasma magnesium, which determines the levels of magnesium outside your cells, may not accurately reflect your true body stores of this important mineral. Thus, the definition of hypomagnesemia, or low magnesium, varies somewhat among different laboratories. "The Merck Manual of Diagnosis and Therapy" defines hypomagnesemia as a plasma level less than 1.4 mEq/L. This level usually indicates that total body stores are depleted as well.

Deficiency

Haas contends that magnesium deficiency is fairly common, due to low levels of magnesium in soft water and in processed and cooked foods. Early signs of deficiency include fatigue, irritability, insomnia, restlessness and loss of appetite. As deficiency worsens, muscle twitches, nausea and vomiting, weakness, personality changes, heart rhythm disturbances and severe muscle spasms develop. Magnesium deficiency has been associated with diabetes, coronary artery disease, osteoporosis, high blood pressure and vascular headaches, such as migraines and cluster headaches.

Migraine

Magnesium is required by many enzymatic processes, and it helps to balance the movement of ions, such as calcium and potassium, across cell membranes. This connection with cellular energy production and ion flux may account for magnesium's influence on vascular headaches, which often involve changes in the muscular tone of the blood vessels in your brain, according to experts at the Jefferson Headache Center in Philadelphia. A study published in the June 1996 "Cephalalgia" demonstrated that a daily dose of 600 mg of oral trimagnesium citrate decreased the frequency of migraines by over 40 percent among the study's subjects. Intravenous magnesium sulfate is sometimes used to treat migraine headaches in emergency rooms.

Considerations

Magnesium deficiency is probably more common than is indicated by routine laboratory tests, which only measure the small amount of magnesium that is found outside your cells. Current recommended dietary allowances for magnesium vary from 30 mg for infants to 420 mg for adult males. Larger doses may be needed for preventing migraine headaches or for addressing signs of magnesium deficiency, such as tremor, insomnia, irritability or restlessness. Ask your doctor if you should take more magnesium.