Should you be taking Magnesium?

It wasn’t until I started my courses in nutrition that I really became aware of the mineral magnesium and its importance to the body.  Magnesium didn’t show up in everyday conversation like that of “take Vitamin C to combat colds, drink milk for calcium for bones “etc.  It's surprising given that Magnesium has a role in over 300 processes in the body.  Some of them include:

  • Facilitates calcium’s absorption and metabolism therefore contributes to the strength and firmness of our bones and teeth
  • Helps the movement of calcium and potassium across the cell membrane influencing nerve impulse conduction, muscle contraction, and normal heart rhythm.
  • It helps normalize high blood pressure.   When I was a nursing student, I remember MagSulfate being used in cases of eclampsia in labor and delivery.
  • Glucose control,             
  • Vitamin D absorption
  • And there is some thought about its role in Cancer because of its role in the synthesis of Glutathione – a major antioxidant.
For something so important, it is worrisome that 80% of those tested are deficient in Magnesium.  So why are we deficient and then there is the follow up question of how to know if you are? The answers to these questions are not simple.  

Why Could You Be Deficient?

Normally we get our magnesium through our diet (the highest  concentrations are in dark leafy greens, and nuts & seeds.) It is estimated that only 40 to 60% of ingested magnesium is absorbed. At the same time, current farming methods are affecting soil levels of magnesium.  Plants take up magnesium together with sun light to produce chlorophyll.  Now add to this scenario medication usage such as diuretics, birth control pills, antacids, antibiotics and/or medical conditions such as Vitamin D deficiency, intestinal malabsorption (think Crohn’s disease, IBO etc.) and liver disease all which can deplete magnesium and Houston we have a problem!

How to Know If You Are Deficient?

Well the singular serum magnesium blood test is not the most effective tool in establishing the diagnosis of magnesium deficiency. That’s because normally less than one percent of magnesium is found in the blood to begin with; 50 -60% is in bone, and the rest in soft tissues.  So you are not really measuring total body magnesium.  Sometimes you have other testing to take into account.  (There is something called the 10/4 or calcium magnesium ratio and there is also a delicate balance between magnesium, Vitamin D and K2 but that’s another post in itself.)  So now you add in the clinical presentation – i.e. what symptoms are present.  With magnesium engaged in over 300 bodily processes, there can be that many potential symptoms.  Here is a short list below obtained from this source.  The more you have the more likely magnesium could be the culprit.

Suggestive early warning signs of magnesium insufficiency:
  • Physical and mental fatigue
  • Persistent under-eye twitch
  • Tension in the upper back, shoulders and neck
  • Headaches
  • Pre-menstrual fluid retention and/or breast tenderness
Possible manifestations of magnesium deficiency include:
  • Low energy
  • Fatigue
  • Weakness
  • Confusion
  • Nervousness
  • Anxiousness
  • Irritability
  • Seizures (and tantrums)
  • Poor digestion
  • PMS and hormonal imbalances
  • Inability to sleep
  • Muscle tension, spasm and cramps
  • Calcification of organs
  • Weakening of the bones
  • Abnormal heart rhythm
Where To Get Magnesium?

It was already stated that diet is the main source of magnesium. The highest sources of magnesium are green leafy vegetables such as spinach, chard, kale;  nuts and seeds such as pumpkin, flax, sesame but it is also found in fish, and most fruits. 

Should You Supplement?   

Supplementing is a personal decision.  You can order the blood test yourself but it may mislead you into thinking you are not deficient. So think about what you have going on in your life, what medications you are taking and presenting symptoms and then take it from there.

How Much Should You Supplement? This is what the NIH fact sheet says:

"In healthy people, the kidneys can get rid of any excess (magnesium)in the urine. But magnesium in dietary supplements and medications should not be consumed in amounts above the upper limit, unless recommended by a health care provider."  *


  Upper Limit for Magnesium
in Dietary Supplements
and Medications
Birth to 12 months    Not established
Children 1–3 years    65 mg
Children 4–8 years   110 MG
Children 9–18 years   350 MG
Adults   350 mg

Table: NIH

*In some instances, a higher magnesium levels might be beneficial such as treating hypertension and thus warding of stroke, osteoporosis, reducing migraines, and in reducing risk for type 2 diabetes.
How To Supplement?

This is an interesting question too.  This article by Dr, Mark Hyman say this· 

  • The most absorbable forms are magnesium citrate, glycinate taurate, or aspartate, although magnesium bound to Kreb cycle chelates (malate, succinate, fumarate) are also good.
  • Avoid magnesium carbonate, sulfate, gluconate, and oxide. They are poorly absorbed (and the cheapest and most common forms found in supplements).
  • Side effects from too much magnesium include diarrhea, which can be avoided if you switch to magnesium glycinate.
Dr. Hyman also mentions baths with Epsom salts that contain magnesium.  I have read (mainly by people advocating for or actually selling products) that trans-dermal e.g. via the skin magnesium products are the best way to supplement. It makes sense because the skin is our largest organ and through its absorption you can bypass some of the issues with oral supplementation. Transdermal applications of medications is not new- think of the nicotine patch, there is transdermal nitoglycerine for cardiac patients, even something for birthcontrol.

Well thank you for staying with me during this long post.  Although, Magnesium isnt as popularized as some of the other vitamins and minerals, we cant afford to overlook it.