By Erica Verrillo
Found abundantly in leafy greens, fish, nuts, seeds,and dried fruits, magnesium is the unsung hero of nearly all our body’s metabolic processes. It is a cofactor in over 300 enzyme systems, and performs vital roles in regulating blood glucose levels, protein synthesis, blood pressure, and muscle and nerve function. Along with potassium, calcium and sodium, it is classed as one of the seven minerals essential for the functioning of the human body. Without it, we would die.
According to the USDA, fully 68% of Americans do not consume the daily recommended intake for magnesium.1 Independent researchers place this figure even higher, at 75% – 80%. 2 (Keep in mind that the daily recommended intake is not the optimal amount a person needs to consume in order to maintain a healthy, fully functioning body, but the minimal amount one needs in order to avoid illness.)
Because magnesium is essential for relaying nervous system impulses and for the metabolism of calcium and potassium, the effects of magnesium deficiency run the gamut, from growth retardation to heart failure, from anorexia to learning disabilities and personality changes, from weakness to muscle pain, and, of course, fatigue. Even at the daily recommended intake, symptoms of deficiency can appear. In 1990, Kubena et al. listed the effects of chronic marginal intakes of magnesium, including “abnormalities in reproduction, growth, and development and disorders of neuromuscular, cardiovascular, renal, and immune function.” 9 Considering the fact that roughly three-quarters of Americans are functionally deficient in magnesium, we would expect to see at least mild deficiency symptoms in the majority of our population.
Given both its widespread systemic effects as well as its under-consumption by most of the population, it is not surprising that magnesium has been used as a treatment for such diverse conditions as diabetes, cardiac disorders, migraines, asthma, and major depression. 3-7
Magnesium Deficiency in ME/CFS
In early 1991, I.M. Cox, M.J. Campbell, and D. Dowson published a preliminary study on magnesium levels in CFS/ME patients. All 22 patients studied had reduced levels of serum magnesium. 10 (A reduced level of serum magnesium is cause for alarm, given that the vast majority of magnesium is found in tissue, not blood.) The researchers followed up their findings with a randomized clinical study in which 15 of the patients received intramuscular injections of magnesium sulfate every week for six weeks and 17 received a placebo. Of the 15 patients receiving magnesium, 12 reported improvement in symptoms.
A subsequent article by Dr. Mildred Seelig observed an overlap with ME/CFS and many of the symptoms of latent tetany syndrome, a medical condition resulting from magnesium deficiency leading to sleep abnormalities, vertigo, mitral valve prolapse, headaches, and anxiety. She proposed that ME/CFS patients would improve with the treatment used for LTS, namely magnesium. 8 Dr. Seelig concluded that “The evidence that Mg deficiency causes a variety of both humoral and cellular defense disturbances, among which are several that have been identified in CFS and FM, is a reason to suspect that either Mg deficiency or its abnormal utilization might be a pathogenic factor in CFS.”
Dr. Martin Pall’s work supports Dr. Seelig’s conclusion. Dr. Pall speculated that, given the likelihood that people with CFS/ME are marginally deficient in magnesium before falling ill, magnesium deficiency may actually contribute to the pathogenesis of the illness. In his book, Explaining “Unexplained Illnesses,” Dr. Martin Pall presents a compelling argument implicating oxidative stress in the etiology of CFS/ME. 11 An important part of the cycle of oxidative stress typical of multisystem illnesses like CFS/ME, FM and Gulf War Syndrome is the chronic excitability of NMDA receptors. This over-excitability results in a hyperactive nervous system – along with cell damage, inflammation, and lowered production of ATP. Magnesium is one of the principal inhibitors of NMDA activity, which makes it a valuable treatment for any illness involving chronic oxidative stress.
In addition to its contribution to oxidative stress, Dr. Myhill believes that low magnesium levels in CFS/ME patients is a symptom of mitochondrial failure. When mitochondria fail, calcium leaks into cells and magnesium leaks out. According to Dr. Myhill, this leakage explains why it is useless to test serum levels of magnesium. As she puts it, “Serum levels are maintained at the expense of intracellular levels. If serum levels change this causes heart irregularities and so the body maintains serum levels at all cost. It will drain magnesium from inside cells and indeed from bone in order to achieve this.” 12 Dr. Myhill’s explanation not only accounts for why serum levels of magnesium are inconsistent in CFS/ME, but why magnesium supplementation is so effective.
Treating ME/CFS With Magnesium
Although nearly every CFS/ME physician includes either injectable or oral magnesium as part of their protocol, there are relatively few studies measuring the overall effects of magnesium supplementation. The paucity of studies may be due to the fact that body stores of magnesium cannot be measured via a blood test. However, one of the few formal studies (Manuel y Keenoy et al.) found that supplementation with magnesium led to an improvement in magnesium body stores, as well as serum vitamin E levels in ME/CFS patients.13 The results of that study indicate that magnesium supplementation not only leads to increased body stores, but may reduce oxidative stress (as indicated by the increase in vitamin E levels).
What Form to Take?
Subscribe to the World's Most Popular Newsletter (it's free!)
Because oral magnesium is difficult to absorb, the forms most frequently recommended are magnesium citrate and magnesium glycinate. Magnesium citrate dissolves in water, which makes it more bioavailable than most other forms of magnesium (such as sulfate or oxide, both of which are inorganic and poorly absorbed 14).
Dr. Paul Cheney has observed that magnesium glycinate causes the least intestinal upset and is the most easily absorbed.15 The usual recommended dosage is 200 to 400 mg/day taken with food, although CFS/ME patients are cautioned to start with a smaller dose and increase it gradually. Intramuscular injections of 1 cc of magnesium sulfate (50%) or magnesium chloride can be administered once or twice a week. Because of magnesium’s effect on heart function, the first injection should be performed in a physician’s office. The main drawback of injected magnesium is that the injections are painful. The simultaneous administration of vitamin B12 or lidocaine helps relieve the pain of the injection. Because magnesium is a cathartic, high doses can cause diarrhea. In patients prone to gastrointestinal upset, a low dose is normally recommended.
Most people with ME/CFS who take magnesium, whether oral or injected, report increased stamina and energy. Many include better sleep as an additional benefit (most likely due to magnesium’s muscle-relaxing effects).
MAGNESIUM IN A NUTSHELL
- Increases energy
- Decreases pain
- Helps insomnia
- Reduces oxidative stress
- Immune system regulator
- Oral forms are effective
- A high dose may cause diarrhea
Excellent summary of magnesium’s effects on the body from the Linus Pauling Institute .
USDA statistics  on nutrient consumption by state and nationally.
- USDA Agricultural Research Service , “Percentage of individuals meeting DRI – Magnesium – 32 per cent”
- Ford ES, Mokdad AH. Dietary magnesium intake in a national sample of U.S. adults. J Nutr  2003;133: 2879-2882.
- Rude RK. Magnesium deficiency and diabetes mellitus: Causes and effects. Postgrad Med  1992; 92: 222-4.
- Iseri LT, Freed J, Bures AR. Magnesium deficiency and cardiac disorders. Am J Med  1975;58:837-46.
- Mauskop A, Altura BM. Role of magnesium in the pathogenesis and treatment of migraines. Clin Neurosci . 1998;5(1):24-7.
- Marcela Davalos Bichara and Ran D. Goldman, MD. Magnesium for treatment of asthma in children. Canadian Family Physician . September 2009 vol. 55no. 9 887-889.
- George A. Eby , Karen L. Eby. Rapid recovery from major depression using magnesium treatment. Medical Hypotheses  (2006)
- Seelig, Mildred MD, MPH. “Review and Hypothesis: Might Patients with the Chronic Fatigue Syndrome Have Latent Tetany of Magnesium Deficiency.” Journal of Chronic Fatigue Syndrome , Vol. 4(2) 1998
- Kubena KS, Durlach J. “Historical review of the effects of marginal intake of magnesium in chronic experimental magnesium deficiency.” Magnes Res .1990 Sep;3(3):219-26.
- Cox IM, Campbell MJ, Dowson D. “Red blood cell magnesium and chronic fatigue syndrome.” Lancet . 1991 Mar 30;337(8744):757-60.
- Pall, Martin. Explaining “Unexplained Illnesses.” CRC Press, 2007.
- Dr. Myhill discusses magnesium deficiency and treatment in CFS/ME patients. DrMyhill.co .
- Manuel y Keenoy, B, Moorkens, G, Vertommen, J, Noe, M, Neve, J, and De Leeuw, I. “Magnesium status and parameters of the oxidant-antioxidant balance in patients with chronic fatigue: effects of supplementation with magnesium.” J Am Coll Nutr . 2000 Jun;19(3):374-82.
- Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. “Magnesium bioavailability from magnesium citrate and magnesium oxide.” J Am Coll Nutr . 1990 Feb;9(1):48-55.
- Carol Sieverling “Dr. Cheney’s Basic Treatment Plan for Chronic Fatigue Syndrome.” ProHealth , 10/19/01.
Erica Verrillo is the author of Chronic Fatigue Syndrome: A Treatment Guide, 2nd Edition, available as an electronic book on Amazon , Barnes & Noble , Kobo  and Payhip  (PDF file). Her website, CFSTreatmentGuide.com , provides practical resources for patients with ME/CFS. She also writes a blog, Onward Through the Fog , with up-to-date news and information about the illness, as well as the full text of CFS: A Treatment Guide, 1st Edition (available in translation). Ms. Verrillo has been the editor of ProHealth’s ME/CFS HealthWatch since February 2013.