Research Article Challenges Magnesium Upper Intake Limits, Proposes Re-evaluation

Research Article Challenges Magnesium Upper Intake Limits, Proposes Re-evaluation

Research Article Challenges Magnesium Intake Limits, Proposes Re-evaluation

On July 22, prominent researchers, Dr. Rebecca Costello, Dr. Andrea Rosanoff, Dr. Forrest Nielsen, and Dr. Christina West, unveiled a groundbreaking scientific perspective on magnesium intake in their article titled “[Perspective: Call for Re-evaluation of the Tolerable Upper Intake Level for Magnesium Supplementation in Adults].”

Published in Science Direct, this pivotal study presents a compelling argument challenging the existing beliefs surrounding magnesium (Mg) intake and advocates for the reconsideration of the current tolerable upper intake level (UL) set in 1997. At that time, concerns about potential diarrhea issues had led to the establishment of a conservative threshold, hindering the exploration of higher magnesium dosages.

By meticulously examining and questioning these concerns, the researchers propose the need to raise the upper limit, potentially leading to increased magnesium supplementation. This, in turn, could reduce the prevalence of undernutrition for this vital nutrient and offer enhanced protection against a multitude of chronic diseases.

For additional information on the study and its findings, please visit the following link:

CMER Sr. Research Fellow, R.B. Costello presented a poster at the recent ASN meeting




The most common question I’m asked about magnesium is “What form of magnesium should I be taking?”    In other words,

What type or form of magnesium is best?   Which form of magnesium is best absorbed?  Which is most bioavailable?


I always answer:


“The research, which I’ve been studying since 1985, tells me over and over that it’s not the form of magnesium that’s important but the dose.   Meta-analysis studies gathering several clinical trials of magnesium for certain conditions, like high blood pressure, show us that the form of magnesium is not what really matters – what really matters is the daily dose of magnesium given.

How much elemental magnesium is in your daily oral supplement?

250 – 500 mg per day if you are very healthy and have a really good diet that is high in micronutrients (vitamins and minerals) including magnesium

600 – 800 mg per day if you are showing any signs of a magnesium deficit:  high blood pressure, high cholesterol, high fasting blood glucose, or if you have none of these but engage regularly in vigorous exercise

800+ mg per day plus transdermal magnesium daily if you have a chronic condition that is magnesium related:  afib, mitral valve prolapse, osteoporosis, copd, depression, cardiovascular disease, or are healing from an operation, illness or have had a recent trauma.

IN all cases, if your GI tract is not comfortable with the high levels of oral magnesium, give a transdermal magnesium a try.   Getting a whole-body massage with Magnify magnesium cream mixed with cocoanut oil or other massage lotion can really do wonders for someone with a magnesium deficit.


Getting a whole-body massage with Magnify magnesium cream mixed with cocoanut oil or other massage lotion can really do wonders for someone with a magnesium deficit.

Transdermal Magnesium research is promising

Transdermal Magnesium research

Transdermal Magnesium research is promising, but in its infancy.

In 2012 Dr. Rosanoff, creator and Director of Research at CMER, developed a transdermal magnesium cream and had it tested in the research laboratory of Prof. Mahavir Chougule at the University of Hawaii School of Pharmacy in Hilo, HI.  He found that magnesium from this cream-mixture did cross human cadaver skin while an aqueous solution of the same magnesium chloride compound did not.   They presented this research at the International Magnesium Conference, Merida Mexico in 2012.    Since Dr. Rosanoff applied for and was granted US. Patent No.  US 10,258,646 B2 on this cream and it was tested against a placebo cream in a human randomly controlled trial that showed magnesium from this cream raised serum magnesium levels in two weeks about the same as oral magnesium supplements raise serum magnesium in three months (1).  This was a small study and its findings need to be confirmed.

This and other transdermal preparations have been used for several years now, and many people report help with cramps, pain, stiffness, chronic fatigue syndrome and fibromyalgia, Parkinson’s as well as other health issues.  Research in transdermal magnesium and these symptoms/conditions is meager, and we hope that researchers will explore the potential of this safe, comfortable, non-oral way to supplement one’s magnesium.

Dr. Rosanoff’s cream can be purchased at

Links and Reference:

  1. Kass L, Rosanoff A, Tanner A, et al. Effect of transdermal magnesium cream on serum and urinary magnesium levels in humans: A pilot study. PloS one 2017;12(4):e0174817. doi: 10.1371/journal.pone.0174817
Vigorous Exercise And Nutritional Magnesium

Vigorous Exercise And Nutritional Magnesium

Vigorous exercise and Nutritional Magnesium

Vigorous activity can influence nutritional magnesium status, and magnesium status can influence physical performance as well as dictate whether vigorous physical activity is healthy or dangerous.  This is true whether the runner is fit or unfit, trained or untrained.

Nutritional magnesium is deeply involved in ATP1 (energy) production, oxygen uptake, central nervous function, electrolyte balance, glucose metabolism, and muscle function, including that all-important muscle—the heart.

During both training and a race or performance, vigorous exercise ups the body’s requirement for nutritional magnesium – not only because of the higher metabolism and muscle contraction where magnesium plays crucial roles but also because of increased magnesium loss in sweat and urine.  It has been estimated that athletes’ general requirement for nutritional magnesium is easily 10 – 20% higher than the general population.  At the same time, nutritional magnesium can be low in modern, processed food diets.  Without a reliable, widely available marker for clinical magnesium status (serum magnesium does not adequately reflect body magnesium status), the combination of increased magnesium need during racing/training plus marginal magnesium intake can make the seemingly healthy choice of running just the opposite.


When magnesium status is healthy and adequate, blood magnesium shows large swings during exercise, more than 10 times larger than when exercising in a marginal or deficient magnesium state.  This wide range of blood magnesium inflow and outflow appears to allow the healthy body to fully function during the high magnesium need of vigorous exercise.  Healthy magnesium stores allow for the large excretions of magnesium in urine and sweat that occur when the body is performing at peak capacity—without dang the er of going into a depleted magnesium state.  These magnesium changes in blood and urine normalize within 24 hours after vigorous exercise in runners adequate in magnesium, unless a deficit has been induced by the exercise bout.  In runners with marginal or deficit magnesium status, the blood levels do not show such wide swings of magnesium during perf the romance, and urine losses are smaller.  It is as if the body is conserving its precious store of magnesium by limiting the body’s ability to perform at its peak.  Thus, it has been shown that supplemental magnesium given to deficient and marginally deficient runners allows measurably increased performance during athletic events.


It’s been known since 1983 that magnesium supplements can alleviate muscle spasms brought on by exercise.  Vigorous exercise induces oxidative stress, which adequate magnesium status allows the body to healthfully withstand.  Vigorous runner while magnesium deficient or marginally deficient can make the body more vulnerable to this extra oxidative stress.  Immune changes are observed with strenuous exercise; a bout of vigorous physical exercise while in marginal or deficient magnesium status can make the immune changes larger.

It is always wise for a person engaged in vigorous physical activity to keep their magnesium status adequate and healthy, keeping in mind that their requirements are higher than the general population, that a strenuous race of long-term training can deplete body magnesium, and that the modern processed food diet can be lower in nutritional magnesium than their high needs require.


Vigorous exercise, such as running in a 10K race, is often a goal of the most health-conscious individuals, not only because it brings a high sense of accomplishment, but because exercise is known to be a healthy lifestyle choice in our modern, sedentary society.  Thus it behooves runners and those in vigorous exercise training to realize that nutritional magnesium status can affect the body’s ability to safely engage in such vigorous physical activity.

  1. ATP  (adenosine triphosphate):  the chemical responsible for cellular energy.


Nielsen, F.H. & Lukaski, H.C.  “Update on the Relationship Between Magnesium and Exercise”  Magnes Res.  2006, Sep; 19(3):180-189.

Seelig, M.S. and Rosanoff, A.  “The Magnesium Factor”  2003, Avery Penguin-Putnam, New York.


During both training and a race or performance, vigorous exercise ups the body’s requirement for nutritional magnesium. . .

It has been estimated that athletes’ general requirement for nutritional magnesium is easily 10 – 20% higher than that of the general population.

the combination of increased magnesium need during racing/training plus marginal magnesium intake can make the seemingly healthy choice of running just the opposite.

Multitasking Magnesium

Multitasking Magnesium

This mineral could benefit a wide array of ailments

Magnesium is a remarkable mineral that doesn’t get anywhere near the credit it deserves for preventing and treating disease,” says Mary Ann Block, DO, founder and medical director of the Block Center in Fort Worth, Texas.
Magnesium is a cofactor in 80% of the body’s metabolic activities, including fundamentals such as energy production, blood sugar regulation, maintenance of electrolyte balance, muscle function, nerve function, protein synthesis, and DNA and RNA synthesis, says Andrea Rosanoff, PhD, director of research and science information outreach at the Center for Magnesium Education and Research in Pahoa, Hawaii. Research suggests that low magnesium levels are linked to hypertension, cardiovascular disease, and Type 2 diabetes.


Nearly half of all American adults have high blood pressure, which is the No. 1 risk factor for heart attack and stroke. In a paper published in the American Journal of Clinical Nutrition, Dr. Rosanoff and her colleagues analyzed 11 studies on high blood pressure that, together, examined over 500 people with prediabetes, insulin resistance, or noncommunicable chronic diseases.

They found that people who took a magnesium supplement (365 to 450 mg daily) had a significant reduction in both systolic and diastolic blood pressure: a mean of 4.18 mm Hg systolic and 2.27 mm Hg diastolic.

Cardiovascular Disease

Magnesium can help prevent cardiovascular disease, says Dr. Rosanoff. In a study that she helped conduct, people at high risk for magnesium deficiency were also found to be at an increased risk for cardiovascular disease.2 Additionally, the study linked low levels of magnesium to systemic inflammation—a risk factor for cardiovascular disease and many other chronic diseases, according to a 2019 paper published in Nature Medicine.


Some research suggests higher magnesium intakes might be associated with improved blood sugar regulation. In an analysis published in the British Journal of Nutrition on January 20, 2022, researchers reviewed the results of 18 studies on magnesium and blood sugar levels. They determined that “oral [magnesium] supplementation could have an effect on glycaemic control in [Type 2 diabetes mellitus] patients,” but cautioned that “the clinical trials so far are not sufficient to make guidelines for clinical practice.”
In an analysis in the Journal of Human Nutrition and Dietetics, researchers found that magnesium supplementation had a favorable effect on cardiovascular risk factors associated with Type 2 diabetes, particularly among people with magnesium deficiency. They concluded: “Magnesium supplementation may decrease the risk [of Type 2 diabetes] associated cardiovascular diseases, although future large RCTs are needed for making robust guidelines for clinical practice.”

Other Health Problems

Perhaps due to the role magnesium plays in many systems and organs, some studies suggest that it might help with a range of other ailments, though the data is often inconclusive:

Insomnia. In a 2021 analysis of past studies, researchers determined that people who took magnesium supplements fell asleep faster and slept longer, though they cautioned that all of the trials they analyzed “were at moderate-to-high risk of bias and outcomes were supported by low to very low
quality of evidence.”

Migraines. A cross-sectional analysis published in Headache reviewed health data from more than 3,600 people and found that people who had higher magnesium intakes had a lower risk of experiencing migraines.

Nonalcoholic fatty liver disease. In a study published in the European Journal of Nutrition, scientists from Columbia University examined 25 years of health data from 2,685 people and found that people in the top quintile of magnesium intakes were 55% less likely to develop the disease than people in the lowest intake quintile.

Stress. In a study published in the journal Stress and Health, people who had low magnesium levels and were under severe stress but were otherwise healthy took 300 mg of magnesium a day for eight weeks. Anxiety and depression scores significantly improved among the participants. “Magnesium supplementation … could provide a meaningful clinical benefit in daily life for individuals with stress and low magnesemia,” concluded the researchers.

Suboptimal Intake Is Common

Magnesium deficiency is uncommon, occurring in less than 2% of the population, says Dr. Rosanoff, but suboptimal intake is very common. According to the National Health and Nutrition Examination Survey, 79% of American adults do not meet their recommended daily allowance for magnesium: 400 to 420 for men and 310 to 320 for women—and these values, published in 1997, are low compared to the body’s need for magnesium.

“I consider the low intake of magnesium to be the single most important nutritional deficit in the United
States,” says Jacob Teitelbaum, MD, an internist in Kona, Hawaii. That’s because a low intake could be
playing a major role in the current epidemics of heart disease, stroke, and Type 2 diabetes, he notes.

Recommending a Supplement

Magnesium supplements are inexpensive and safe, says Dr. Rosanoff. For a person taking a magnesium supplement to prevent illness, Dr. Rosanoff recommends 350 mg daily. If your patient has a clinical issue that magnesium might help, such as high blood pressure or blood sugar levels, Dr. Rosanoff thinks 600 mg daily in a single dose before bedtime is agood recommendation.

If that amount produces loose stools—a possible side effect of magnesium supplementation—the patient should divide the amount into two 300 mg doses or three 200 mg doses. Or they should cut back on the single dose by 100 mg every few days, until their bowel movements normalize, Dr. Rosanoff notes.

Dr. Block routinely recommends 500 mg daily to her patients—increasing it gradually until the patient reaches bowel tolerance and then cutting back slightly until the bowel movements are again well-formed.

And don’t forget to remind patients to eat magnesium-rich foods, says Dr. Teitelbaum, who recommends leafy greens and nuts, especially almonds, as the best dietary sources of the mineral. Other foods rich in magnesium include dark chocolate, avocados, beans, whole grains, and bananas.

More information:

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