A fasciculation (fah SIK yoo lay shun) (or “muscle twitch”) is a small, local, involuntary muscle contraction (twitching) visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle fibers. Fasciculations have a variety of causes, the majority of which are benign, but can also be due to disease of the motor neurons.

Inadequate magnesium intake can cause fasciculations, especially after a magnesium loss due to severe diarrhea. Over-exertion is another risk factor for magnesium loss. As 70-80% of the adult population does not consume the recommended daily amount of magnesium, inadequate intake may also be a common cause. Treatment consists of magnesium supplements or increased intake of foods rich in magnesium, such as nuts (especially almonds) and bananas. Ironically, magnesium supplements may cause diarrhea which may cause magnesium loss. This can be managed by adjusting dosage and taking the supplements with meals.

Fasciculation also often occurs during a rest period after sustained stress, such as that brought on by unconsciously tense muscles. Reducing stress and anxiety is therefore another useful treatment.

Magnesium deficiency refers to a lack of dietary magnesium below specified levels, which can result in numerous symptoms and conditions. This can generally be remedied by an alteration of diet or oral supplements.

Symptoms

Symptoms of magnesium deficiency include: hyperexcitability, muscle weakness and tiredness.

Human health

Magnesium deficiency in humans was first described in the medical literature in 1934. The adult human daily nutritional requirement, which is affected by various factors including gender, weight and size, is 300-400 mg/day. Inadequate magnesium intake frequently causes muscle spasms, and has been associated with cardiovascular disease, diabetes, high blood pressure, anxiety disorders, migraines, osteoporosis and cerebral infarction

Nerve Conduction

Magnesium can affect muscle relaxation through direct action on the cell membrane. Mg++ ions close certain types of calcium channels, which conduct a positively charged calcium ion into the neuron. With an excess of magnesium, more channels will be blocked and the nerve will have less activity

Essential role in the biological activity of ATP

ATP (adenosine triphosphate), the main source of energy in cells, must be bound to a magnesium ion in order to be biologically active. What is called ATP is often actually Mg-ATP.

Hypertension

Magnesium-containing Epsom salts are especially used in treating the hypertension of eclampsia.

Food sources

Some good sources of magnesium.

Green vegetables such as spinach provide magnesium because of the abundance of chlorophyll molecules which contain the ion. Nuts (especially cashews and almonds), and some whole grains are also good sources of magnesium.

Although many foods contain magnesium, it is usually found in low levels. As with most nutrients, daily needs for magnesium are unlikely to be met by one serving of any single food. Eating a wide variety of fruits, vegetables, and grains will help ensure adequate intake of magnesium.

Following are some foods and the amount of magnesium in them:
spinach (1/2 cup) = 80 milligrams (mg)
peanut butter (2 tablespoons) = 50 mg
black-eyed peas (1/2 cup) = 45 mg
milk: low fat (1 cup) = 40 mg
Because magnesium readily dissolves in water, refined foods, which are often processed or cooked in water and dried, are generally poor sources of the nutrient. For example, whole-wheat bread has twice as much magnesium as white bread because the magnesium-rich germ and bran are removed when white flour is processed. The table of food sources of magnesium suggests many dietary sources of magnesium.

“Hard” water can also provide magnesium, but “soft” water does not contain the ion. Dietary surveys do not assess magnesium intake from water, which may lead to underestimating total magnesium intake and its variability.

Too much magnesium may make it difficult for the body to absorb calcium. Not enough magnesium can lead to hypomagnesemia as described above, with irregular heartbeats, high blood pressure, insomnia and muscle spasms (fasciculation). However, as noted, symptoms of low magnesium from pure dietary deficiency are thought to be rarely encountered.