Background InformationWhile calcium gets most of the attention, magnesium is just as much of a major essential mineral and may be a much more important supplement consideration for many. Over 50% of the body’s magnesium is contained in the bones. Magnesium is found inside cells throughout the body with only a minimal amount found free (unbound) in the blood stream. Magnesium is absolutely critical to cellular function and plays a key role in:

  • Blood clotting
  • Brain chemistry
  • Muscle contraction
  • Energy metabolism
  • Immune function
  • Insulin sensitivity and the body’s use of glucose
  • Respiratory function
  • Regulating blood pressure
  • Synthesis of many body compounds

Signs and symptoms of severe magnesium deficiency include fatigue, mental confusion, irritability, weakness, heart disturbances, problems in nerve conduction and muscle contraction, muscle cramps, loss of appetite, insomnia, and a predisposition to stress.


The Importance of Magnesium Supplementation

The usual recommendation for magnesium is supplementation at the level of the Recommended Dietary Allowance (RDA): 350 mg per day for adult males and 280 mg per day for adult females. Since the average daily intake of magnesium in the United States is only 266 mg, magnesium insufficiency is extremely common in Americans making magnesium supplementation critical for many.

Magnesium supplementation has been shown to have tremendous beneficial effects in the following health conditions:

  • Asthma and chronic obstructive pulmonary disease (COPD)
  • Attention deficit disorder (ADD) with hyperactivity (ADHD)
  • Cardiovascular disease
    • Angina
    • Arrhythmias
    • Congestive heart failure
    • High blood pressure
    • Diabetes
    • Fatigue
    • Fibromyalgia
    • Kidney stones
    • Migraine and tension headaches
    • Osteoporosis
    • Pregnancy (toxemia, premature delivery, and other complications)
    • Premenstrual syndrome

New Data

Magnesium’s role in preventing heart disease and strokes is generally well-accepted. Low magnesium (Mg) intake is also associated with increased incidence of diabetes mellitus, metabolic syndrome, and all-cause mortality. Historically it has generally been thought that easily ionized forms of magnesium like Mg citrate or aspartate are significantly better absorbed than magnesium salts like Mg oxide. However, a new study challenges that position.

In this double-blind study, researchers investigated the impact of supplemental oral Mg citrate versus Mg oxide on intracellular magnesium levels ([Mg2+]i) in healthy subjects. Healthy volunteers received either magnesium oxide tablets (520 mg/day of elemental magnesium) or magnesium citrate tablets (295.8 mg/day of elemental magnesium) for one month (phase 1), followed by a four-week wash-out period, and then crossover treatment for one month (phase 2). Using new analytical techniques (x-ray dispersion analysis) results showed Mg oxide produced a [Mg2+]i level of 36.3 mEq/L vs. 35.4 mEq/L for Mg citrate and reduced total and LDL cholesterol more significantly as well. Both forms also reduced platelet aggregation

Since the dosage of magnesium was also greater in the Mg oxide group, what these results indicate is that MG oxide as suitable of a form of magnesium as Mg citrate when given at larger dosage levels. Approximately 500 mg of Mg oxide may be equal to 350 mg Mg citrate.



Shechter M, Saad T, Shechter A, et al. Comparison of magnesium status using X-ray dispersion analysis following magnesium oxide and magnesium citrate treatment of healthy subjects. Magnes Res. 2012 Mar 1;25(1):28-39.

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