Magnesium

Figure 1. The crystal structure of Magnesium.

Magnesium is a chemical element with the symbol Mg and atomic number 12. Magnesium is the eighth most abundant element in the Earth's crust and the fourth most common element in the Earth (after iron, oxygen, and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle. It is the third most abundant element dissolved in seawater, after sodium and chlorine.

Magnesium is the eleventh most abundant element by mass in the human body and is essential to all cells and some 300 enzymes. Magnesium ions interact with polyphosphate compounds such as ATP (provides cells their energy), DNA (genetic instructions), and RNA (coding, decoding, regulating, and expressing genes). Within the human body, hundreds of enzymes require magnesium ions to function such as building proteins and strong bones, and regulating blood sugar, blood pressure, and muscle and nerve functions. Magnesium also acts an electrical conductor that contracts muscles and makes the heart beat steadily.

More than half of the magnesium in our body is stored in bones, and the remaining in various tissues throughout the body.

Food Sources

Magnesium is an essential trace mineral for the human body, hence it can only be obtained from one's diet. Magnesium is found in plant foods like legumes, dark green leafy vegetables, nuts, seeds, whole grains, and fortified cereals. It is also in fish, poultry, and beef. Some food sources for Magnesium include:

• Almonds, peanuts, cashews
• Pumpkin seeds
• Peanut butter
• Beans (black, kidney)
• Soybeans, soymilk
• Cooked spinach, Swiss chard
• White potato with skin
• Brown rice
• Oatmeal (instant, whole oats)
• Salmon
• Beef
• Poultry
• Banana
• Raisins
• Dark chocolate (at least 70%)
• Milk, yogurt

The Recommended Dietary Allowance (RDA) for adults 19-51+ years is 400mg-420mg daily for men and 310mg-320mg for women. Pregnancy requires about 350mg-360mg daily and lactation, 310mg-320mg.

Taken as a Dietary Supplement

Magnesium is a key factor in making several parts of the body run smoothly: the heart, bones, muscles, nerves, and others. Without enough magnesium, these areas malfunction. Magnesium deficiency (hypomagnesemia, or low plasma magensium) may result in symptoms of neuromuscular, cardiovascular, and metabolic dysfunction. These symptoms include fatigue, weakness, poor appetite, nausea, vomiting, numbness or tingling in skin, muscle cramps, seizures, and abnormal heart rate.

As a dietary supplement, Magnesium is often taken to help with Magnesium deficiency. However, Magnesium supplements are often promoted to help with bone health, migraines, depression, cardiovascular diseases, and diabetes as well, due to the essential roles Magnesium plays in these areas of bodily function.

Over-the-counter magnesium supplements can come in different forms. Liquid types like Magnesium Citrate or Magnesium Chloride may be better absorbed than solid tablets like Magnesium Oxide and Magnesium Sulfate.

Side Effects

Magnesium can have a laxative effect at high doses. In fact, Magnesium is sold as a laxative in the form of Magnesium Hydroxide. Magnesium Hydroxide is also an ingredient in some antacids to treat heartburn and upset stomach, so it is important to be aware of its laxative effects beforehand.

People with kidney disease may experience Magnesium toxicity in the human body (i.e. kidneys unable to flush out excess Magnesium via the urine). Signs of toxicity include excessive nausea, vomiting, diarrhoea, low mood/depression, muscle weakness, low blood pressure, abnormal heartbeat, or heart attack.