What is magnesium?

  • Magnesium is a mineral

Why is magnesium important? 

  • According to the NIH, “Magnesium is a cofactor in more than 300 enzyme systems”

Magnesium is needed for,

  • protein synthesis
  • blood glucose control and blood pressure regulation
  • nerve conduction,
  • muscle contraction
  • normal heart rhythm
  • Energy production
  • producing DNA and RNA
  • Source-NIH

Magnesium levels in our bodies

  • Magnesium balance is controlled by the kidneys

How do we know we have low magnesium levels?

  • According to the NIH, “Assessing magnesium status is difficult because most magnesium is inside cells or in bone”
  • “The most commonly used and readily available method for assessing magnesium status is measurement of serum magnesium concentration, even though serum levels have little correlation with total body magnesium levels or concentrations in specific tissues.” Source NIH

Recommended Dietary Allowances (RDAs) for Magnesium

Males     Females

31–50 years 420 mg 320 mg
51+ years 420 mg 320 mg

Resource NIH

vitamin D informationSources of magnesium


  • Spinach and Almonds- 1 once 80mg 20% of the recommended daily allowance.
  • Cashews have 19% of the RDA.
  • Peanuts, black beans, and soy milk have  15% of the RDA.




  • Magnesium is found in laxatives and anti-acids.

Magnesium levels in Americans

  • “No current data on magnesium status in the United States are available.” source NIH

Magnesium deficiency

  • “Symptomatic magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon because the kidneys limit urinary excretion of this mineral.” NIH

There are certain diseases that will increase the risk of magnesium deficiency.

Risk factors for magnesium deficiency

  • Age decreases magnesium absorption in the bowel and increases magnesium excretion in the kidney.
  • Those with diabetes, especially if uncontrolled. It is thought that the kidneys may excrete more magnesium with higher blood sugar levels.
  • Those with kidney problems.
  • Crohn’s disease- Crohn’s patients typically have malabsorption problems.
  • Alcohol abuse leads to poor nutritional intake, malabsorption, and kidney problems, all of which increase the risk for magnesium deficiency.

Certain medications have been shown to decrease magnesium levels.

  • Those taking proton pump inhibitors such as Nexium that is used to treat  gastric reflux can lower magnesium levels-NIH
  • Water pills can also decrease magnesium levels (some can actually increase magnesium levels).

Signs of magnesium deficiency

  • “Early signs of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness.”
  • ‘As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur”
  • “Severe magnesium deficiency can result in hypocalcemia or hypokalemia (low serum calcium or potassium levels, respectively) because mineral homeostasis is disrupted”



  • There are a number of different magnesium supplements available such as magnesium oxide, citrate, and chloride.
  • Magnesium aspartate, citrate, lactate, and chloride forms may be better absorbed than magnesium oxide and magnesium sulfate.
  • Diarrhea and cramping can occur with supplements or if too much magnesium is taken.
  • Resource NIH

It is important to note what when magnesium is given in the hospital it is usually given intravenously. An infusion pump allows magnesium to drip in slowly and the patients are usually monitored.

Magnesium and absorption of other medications

  • Use of magnesium-rich supplements or medications such as anti-acids and oral bisphosphonates used to treat thin bones (osteoporosis) should be separated by at least 2 hours.
  • Magnesium will affect the absorption of antibiotics such as tetracycline and ciprofloxacin.
  • Diuretics  (water pills) depending on which one can increase or decrease magnesium excretion.
  • Magnesium supplements can make a patient more sensitive to muscle relaxants Source-Web MD

What are the proven benefits of magnesium

  • Constipation relief
  • Heartburn relief
  • High blood pressure during pregnancy referred to as preeclampsia or eclampsia.
  • It can also help with certain irregular heart rhythms (torsades de pointes).

Blood pressure and magnesium

  • “Magnesium intake may reduce blood pressure slightly”
  • “Dietary Approaches to Stop Hypertension (DASH) diet also increases intakes of other nutrients, such as potassium and calcium, that are associated with reductions in blood pressure, so any independent contribution of magnesium cannot be determined.”
  • Source-NIH

Heart disease and magnesium

  • Risk of heart disease may be reduced
  • Stoke risk may be reduced
  • Source NIH

These are observational studies, there may be other factors. People who eat more vegetables and nuts generally have a healthier diet and lifestyle.

“A large, well-designed clinical trial is needed to better understand the contributions of magnesium from food and dietary supplements to heart health and the primary prevention of cardiovascular disease” NIH

Diabetes and Magnesium 

  • “Only a few small, short-term clinical trials have examined the potential effects of supplemental magnesium on control of type 2 diabetes and the results are conflicting”
  • The American Diabetes Association states that there is insufficient evidence to support the routine use of magnesium to improve glycemic control in people with diabetes.
  • The American Diabetes Association notes that there is no clear scientific evidence that vitamin and mineral supplementation benefits people with diabetes who do not have underlying nutritional deficiencies.
  • NIH

Bone Health and Magnesium 

  • Magnesium is involved in bone formation, it influences the cells that make and break down bone (osteoblasts and osteoclasts).
  • Magnesium affects parathyroid hormone and the active form of vitamin D, which are major regulators of bone homeostasis.
  • “Diets that provide recommended levels of magnesium enhance bone health, but further research is needed to elucidate the role of magnesium in the prevention and management of osteoporosis.” NIH

Migraine headaches

  • People who experience migraine headaches have lower levels of serum and tissue magnesium than those who do not.
  • “In their evidence-based guideline update, the American Academy of Neurology and the American Headache Society concluded that magnesium therapy is “probably effective” for migraine prevention.
  • Because the typical dose of magnesium used for migraine prevention exceeds the upper limit, this treatment should be used only under the direction and supervision of a healthcare provider.”

Magnesium and asthma

  • There are some studies to support possible benefit when used as an inhaler for children with asthma. Other studies show, “Continuous nebulization, addition of magnesium sulfate to SABA, and levosalbutamol compared to salbutamol cannot be recommended in routine practice.”
  • Findings are inconclusive, more research is needed.

Reference Pollock M1, Sinha IP2, Hartling L1, Rowe BH3, Schreiber S1, Fernandes RM4,5.Allergy 2017 Feb;72(2):183-200. doi: 10.1111/all.13039. Epub 2016 Oct 5.

Magnesium and pain

  • There are a few studies that suggest intravenous magnesium may help reduce pain in postoperative patients such as those with hysterectomy and esophageal cancer
  • Those with nerve pain from cancer and fibromyalgia may also exhibit some benefit.
  • Magnesium supplements did not appear effective for those with chronic pain after an injury.
  • Pain is difficult to measure from person to person.
  • Magnesium is unproven for pain relief, additional studies are needed.

Magnesium and athletic performance

  • Taking magnesium by mouth does not seem to increase energy or endurance during athletic activity.-literature review Web MD
  • Supplementation of magnesium lactate dihydrate and calcium lactate monohydrate does not appear to significantly improve times during a simulated 20-km time trial and therefore should not be recommended for use as an ergogenic aid. Reference-Peveler WW1, Palmer TG. Journal Strength Cond Res. 2012 Apr;26(4):1149-53.

Overdose of magnesium

  • “Too much magnesium from food does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine. -NIH
  • High doses of magnesium supplements or medications often result in diarrhea that can be accompanied by nausea and cramping. 
  •  Diarrhea and laxative effects of magnesium salts are due to the osmotic activity of unabsorbed salts in the intestine and colon and the stimulation of gastric motility 
  • Very large doses of magnesium-containing laxatives and antacids (typically providing more than 5,000 mg/day magnesium) have been associated with magnesium toxicity, including fatal hypermagnesemia

What are the symptoms of magnesium overdose?

  • “Symptoms of magnesium toxicity, which usually develop after serum concentrations exceed 1.74–2.61 mmol/L.”
  • Patients may exhibit low blood pressure, nausea, vomiting.
  • There may be difficulty urinating and passing bowel movements.
  • Depression and lethargy can also occur
  • Muscle weakness, difficulty breathing, extreme hypotension, irregular heartbeat, and cardiac arrest are all possible.
  • The risk of magnesium toxicity increases with impaired renal function or kidney failure because the ability to remove excess magnesium is reduced or lost.”
  • Source NIH

My concerns about magnesium supplements

  • There seems to be a big push for magnesium supplementation.
  • I wanted to speak about magnesium today because I am concerned about taking supplements whether by mouth or in an oil form that are not supervised.
  • The oral form may cause diarrhea which is a good thing, perhaps you would question taking the supplement or question your doctor.
  • Magnesium oil supplement that is placed on the skin is unlikely to cause diarrhea as the gastrointestinal tract is avoided, you bypass it.
  •  I am not sure anyone knows how many milligrams they are absorbing through their skin, this is a problem as there are side effects with too much magnesium.
  • I am not aware of any good studies proving the health benefit of magnesium oil.
  • On the other hand, it does make sense that there may be some safety issues when taking an unknown amount of magnesium.
  • I urge you to do your research, know how many milligrams you are taking and speak to your doctor.


Reference Magnesium and insomniaAbbasi B1, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B.J Res Med Sci. 2012 Dec;17(12):1161-9. “Supplementation of magnesium appears to improve subjective measures of insomnia such as ISI score, sleep efficiency, sleep time and sleep onset latency, early morning awakening, and likewise, insomnia objective measures such as concentration of serum renin, melatonin, and serum cortisol, in elderly people.”

McCarty Med Hypotheses. 1996 Dec;47(6):461-6.


World Health Organization http://apps.who.int/iris/bitstream/10665/43836/1/9789241563550_eng.pdf

Web MD

What do you think about magnesium supplements?

Spread the love