Magnesium Deficiency

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Magnesium deficiency in humans can be mild or severe, and studies suggest it is more and more common. Reports published by the World Health Organization have estimated that three quarters of Americans do not meet the Recommended Daily Intake (RDI) of magnesium.1

How serious is this problem? Average magnesium intake in the U.S. has dwindled to less than half what it was a century ago:

  • In the year 1900: 500 mg per day
  • Today: 175-225 mg per day2

Magnesium deficiency has far-reaching impacts on health and well-being. Evidence has linked insufficient intake to a variety of conditions and symptoms, from simple irritability to chronic pain to life-threatening disease.

In This Section

Get the facts on magnesium deficiency in the following articles:

Magnesium Deficiency Symptoms
A complete list of the symptoms of low magnesium, including both neurological and muscular effects such as depression, fatigue, muscle cramps and abnormal heart rhythms.

Magnesium Deficiency Causes
Even those with a balanced diet rich in magnesium sources can suffer from deficiencies. Learn about the risk factors for deficiency.

Need More Magnesium? 10 Signs to Watch For
Get a sense of where your intake may lie simply by asking yourself a few questions.

Statistics on Magnesium Deficiency

With the current U.S. adult RDA of magnesium of 320-420 mg per day3 , the average American’s intake is only slightly more than half the minimum amount of magnesium required to function effectively.2 In fact, even this drastic figure may be an understatement. Many medical researchers find the RDA figures inadequate to prevent deficiencies of magnesium and chronic disease.4

Optimal Daily Intake was set at 500-750 mg for men and women, nearly double the current RDA.For example, The Real Vitamin & Mineral Book, a bestseller now in its fourth edition,establishes ODI, “Optimal Daily Intake” amounts — amounts necessary not just to prevent overt deficiency but to maintain optimal health and prevent disease.

Based on the authors’ thorough reviews of the scientific and medical literature and their work in clinical nutrition, the ODI for magnesium was set at 500-750 mg for men and women, nearly double the current RDA.5 Interestingly, these amounts are closer to the amounts commonly consumed before mass agricultural and food processing practices were taken up in the West.

By these estimations, modern deficiencies are both far more common and far more severe.

Other Western countries today exhibit similar deficiencies. In France, a study found that over 70% of men and nearly 80% of women were magnesium-deficient in their diets.6

In Finland, authorities were so convinced of the impact of magnesium deficiency on heart health that its government instituted a nationwide campaign to increase magnesium intake through magnesium salt substitutes. Finland’s death rates due to heart-related issues fell from number one in the world to down to 10th.7

The following chart compares mean intake of magnesium in various countries with the recommended daily intake from three sources. In no case is the average intake sufficient to meet even the lowest recommended intake.

Average Daily Magnesium Intake US RDA
(420 mg *)
% Supplied
DASH diet
(500 mg**)
% Supplied
Lieberman ODI
(750 mg ***)
% Supplied
U.S. 212 mg 50% 42% 28%
Canada 244 mg 58% 49% 33%
France 330 mg 79% 66% 44%
Guam 270 mg 64% 54% 36%
Israel 249 mg 59% 50% 33%
South Africa 257 mg 61% 51% 34%

Sources:1 2 3 5
* RDA for adult males over 31
** DASH Diet (Dietary Approaches to Stop Hypertension)
*** Optimal Daily Intake of 500-750 mg for men and women, 500-1000 suggested for those suffering from angina or osteoporosis

Why aren’t magnesium deficiencies more widely recognized?

While some signs and signals of depleted magnesium are more obvious, a wide variety of mild symptoms may indicate a subclinical deficiency. Reasons for magnesium depletion can include dietary, environmental, and drug-related factors.

Despite its prevalence, magnesium deficiencies often go unnoticed, undiagnosed, and untreated by health professionals, even when symptoms are present. Why?

Experts have offered a few possible explanations:

Explanation #1: Accurate magnesium tests are not available.

The accepted method of testing for human magnesium deficiency by the American Medical Association is the serum magnesium test, which assesses the amount of magnesium found in the blood. However, studies have shown that, within the bounds of normal blood levels set for magnesium by the AMA, true magnesium deficiencies still occur.

Dr. Ronald Elin, M.D. Ph.D., of the Department of Pathology and Laboratory Medicine at the University of Louisville has stated:

Serum and red blood cell magnesium concentrations have been shown to be poor predictors of intracellular magnesium concentration.”1

The inability of serum magnesium tests to diagnose magnesium depletion accurately is due to the fact that only 1% of the magnesium found in the body is actually located in the blood. And, as the body works with superior efficiency to keep the blood supply within a tight constant, even those with outright magnesium deficits can test within “normal” ranges.

Doctors Dierck-Hartmut and Dierck-Ekkehard Liebscher have examined closely the use of blood serum testing in magnesium deficiency diagnosis and have found fault specifically with the critical values used to differentiate deficiency from “normal” magnesium levels. Their report, published in the Journal of the American College of Nutrition, finds that as many as 50% of cases of deficiency may go untreated due to errors in reading serum magnesium reports. 8

As many as 50% of cases of deficiency may go untreated due to errors in reading serum magnesium reports.

New methods of magnesium testing are under continuous development, such as the ExaTest offered by Intracellular Diagnosics of California.

Yet many practitioners are not familiar with these methods and their price places them out of reach of many medical researchers. Until a more accurate and affordable method of assessing deficiency in magnesium is more widely employed, only a handful of physicians will have the tools necessary to accurately diagnose the need for magnesium therapy, and provide it for those who truly need it.

This leaves those who may suspect a deficiency with only a few choices:

  • Seek out some of the more advanced, and sometimes more costly, magnesium testing available today,
  • Or, proactively supplement with magnesium in order to test its effect.

Fortunately, magnesium supplementation is both safe and recommended by the leading magnesium experts.

Explanation #2: Magnesium “assists” other functions.

Another reason for a lack of awareness of magnesium deficiency may actually be the breadth of magnesium’s influence on so many of the body’s systems—the nervous, cardiovascular, immune, and muscular systems, to name a few.

  • Because it operates on a cellular level as a “key” to over hundreds of biochemical reactions, symptoms of deficiency may overlap those of alternate causes.
  • Similarly, symptoms may not exclusively identify a deficiency in magnesium as a cause.

A lack of clarity in identifying magnesium deficiency as a sole cause of symptoms may cause some doctors to look elsewhere. Yet many experts recommend the opposite approach: investigating the possibility of magnesium supplementation—a safe, natural, and essential nutrient—before employing other possible treatments.

When discussing pharmaceutical treatments for migraine headaches, for example, Dr. Jay Cohen, an expert on prescription drugs and their side effects, states:

Of all the nutritional and non-drug methods that people can adopt to prevent and treat migraine headaches, magnesium supplementation ranks first.”9

Explanation #3: Magnesium cannot be patented.

Authors and researchers, when writing about magnesium, consistently lament the lack of awareness among doctors of its potential therapeutic applications. The same can be said for an awareness among doctors of the benefits of nutrition in general.

Dr. Jay Cohen, in his book The Magnesium Solution for Migraines and Headaches, writes about his experience attending the Gordon Research Conference, an international conference of magnesium researchers and scientists. He explains:

One of the concerns of the experts at this conference was the difficulty in getting information about magnesium into the hands of everyday practitioners. Without the resources of a drug company for advertising, free seminars, and sales representatives carrying studies and samples to doctors’ offices, it can be very difficult to get independent information into doctors’ awareness.”9

The Real Vitamin and Mineral Book, a bestseller now in its fourth edition, explains very plainly the advantage of pharmaceutical information over nutritional information in its dissemination to the medical community:

It’s all about the money, and the vast majority of dietary supplements are not patentable… It costs more than $400 million to bring a new drug to market — a number out of the reach of any dietary supplement company. And even with great research, supplement companies lack the funds to compete with the billions spent on advertising and lobbying by the pharmaceutical industry.”5

calcium and magnesium in drinking water, world health organization

Medical doctors are trained more heavily in the actions of prescription medications than they are in basic nutrition. When they do enter medical practice a major source of their ongoing education is pharmaceutical companies’ pamphlets and information provided by sales representatives. In many cases, vitamin and mineral treatments may be investigated prior to resorting to drugs. But pharmaceutical companies have no vested interest in accompanying their literature with information about these alternatives.

Yet developments are being made. Researchers like those at the Gordon Conference continue to study the benefits of magnesium, and worldwide organizations have made inroads to public awareness.

  • In 2006, the World Health Organization hosted a panel following the International Symposium on Health Aspects of Calcium and Magnesium in Drinking Water, to examine the potential health benefits of increasing magnesium and calcium levels in worldwide water supplies. Their consensus report acknowledged the evidence for a protective relationship between magnesium, heart health and diabetes.1
  • In March 2005, the George and Patsy Eby Foundation provided funding to distribute 1000 copies of The Magnesium Miracle and The Magnesium Factor to members of Congress.

Correcting Widespread Deficiencies: An Urgent Matter

In his Letter to Congress, George Eby, of the Eby Research Institute, stressed the urgency of correcting America’s severe magnesium deficiency:

If these errors were corrected, I believe millions of lives and hundreds of billions of dollars in cardiac health-care costs would be saved.”10

Controlled trials continue to be called for toward answering the question of whether magnesium supplementation can truly alter the course of diseases like diabetes and hypertension. Yet clear scientific evidence, such as that found in the Atherosclerosis Risk in Communities study, have shown that low dietary and serum magnesium levels do correlate with a higher prevalence of hypertension, diabetes, and atherosclerosis.11

Even beyond its potential role in preventing these widespread conditions, magnesium quietly continues to alter the state of well-being of millions.

Those who suffer from magnesium deficiency experience a wide range of symptoms that can vary from low level to debilitating. And those who choose to correct their deficiencies commonly experience a long sought-after respite from conditions such as migraines, chronic pain, low energy and insomnia.

Considering that an estimated 75% of Americans are magnesium deficient1 , and 19% of Americans consume less than half of the magnesium necessary for health12 , the bulk of evidence points to magnesium supplementation as a pivotal aspect of optimal and preventive health.

What’s next?

Testimonials on magnesium’s results. Find out how others have used magnesium for pain, sleep problems, skin conditions and more.

How much magnesium do you need? Where can you get it? Read Sources of Magnesium to find answers.

How do you choose a magnesium supplement? Learn how to sort out the good from the bad.

  1. World Health Organization. Calcium and Magnesium in Drinking Water: Public health significance. Geneva: World Health Organization Press; 2009. [] [] [] [] []
  2. Altura BM, Altura BT. Magnesium: Forgotten Mineral in Cardiovascular Biology and Therogenesis. In: International Magnesium Symposium. New Perspectives in Magnesium Research. London: Springer-Verlag; 2007:239-260. [] [] []
  3. Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academy Press; 1997. [] []
  4. Dean C. The Magnesium Miracle. New York: Ballantine Books; 2007. []
  5. Lieberman S, Bruning N. The Real Vitamin & Mineral Book. New York: Avery; 2007. [] [] []
  6. Galan P. Dietary magnesium intake in French adult population. In: Theophile T, Anastassopoulou J. Magnesium: current status and new developments: theoretical, biological, and medical aspects. Dordrecht: Kluwer Academic; 1997. []
  7. Seelig M, Rosanoff A. The Magnesium Factor. New York: Avery; 2003. []
  8. Liebscher DH, Liebscher DE. About the misdiagnostics of magnesium deficiency. In: Xth International Magnesium Symposium. Cairns (Australia): 2003. []
  9. Cohen JS. The Magnesium Solution for Migraine Headaches. New York: Square One Publishers; 2004. [] []
  10. Eby G. A Message to U.S. Congress—Magnesium and Health Issues. Georgy Eby Research Institute. 2005. Available at: Accessed September 28, 2009. []
  11. Jing MA, Folsom AR, Melnick SL, et al. Associations of serum and dietary magnesium with cardiovascular disease, hypertension, diabetes, insulin, and carotid arterial wall thickness: the ARIC study. J Clin Epidemiol. 1995;48:927-940. []
  12. King DE, Mainous AG 3rd, Geesey ME, Woolson RF. Dietary magnesium and C-reactive protein levels. Journal of the American College of Nutrition [serial online]. 2005 Jun;24(3):166-71. Available from: MEDLINE with Full Text, Ipswich, MA. Accessed November 6, 2009. []