Signs of Magnesium Deficiency

Magnesium element symbol surrounded by high magnesium foods on black background

Did you know that magnesium is one of the most abundant minerals in your body?  And yet we don’t really hear that much about it from our healthcare providers.

Magnesium deficiency, unfortunately, is difficult to detect with a blood test.  The majority of your body’s magnesium is stored in bones and inside cells, so low levels won’t show up in the blood until you’re well into a deficiency. 

Historically, a balanced diet with plenty of vegetables, nuts/seeds and legumes would provide more than enough magnesium for your average person.  In current times, however, diets high in processed foods have made deficiency more common.  Additionally, modern farming practices have led to a depletion of minerals in soil, which means many of the foods we eat have less magnesium than they used to.

Additionally, certain populations require more magnesium than others, making them more susceptible to deficiency.  One such population is athletes.  More on this to follow…

While there is no perfect test for magnesium deficiency, there are some common signs and symptoms you can look out for.  Read on to learn more!

Why do we need magnesium?

Magnesium is necessary for hundreds of reactions in your body.  Some noteworthy reactions in which magnesium is involved include: development and maintenance of bone, protein synthesis, production of DNA and RNA, glucose metabolism, electrolyte and fluid balance, muscle function, antioxidant regulation, and energy production. (1, 3)

Given magnesium’s impact, whether directly or indirectly, on so many functions in the body, maintaining sufficient levels is critical.  Due to the difficulty to detect insufficient magnesium levels on blood tests, we don’t know how common deficiency really is.  Estimates, however, predict that it may be as much as 50% of adults. (3)

How much magnesium do we need?

Current recommendations for magnesium intake are 400-420 mg/day for men and 310-320 mg/day for women.  As noted, however, some people may need more than recommended amounts.

Athletes lose magnesium through sweat and exercise increases demand for magnesium for things like energy production and muscle contraction.  It’s estimated that exercise decreases magnesium levels in blood by about 10%. (1)    

Magnesium plays a role in eliminating excess estrogen during periods of elevated estrogen in women (just before ovulation and in the mid-luteal phase of menstruation). When estrogen is not efficiently excreted from the body, build-up can lead to symptoms such as trouble sleeping or migraines. (4)

Additionally, individuals with diabetes or digestive issues, those who are taking diuretics, and those who consume large quantities of coffee, soda, alcohol, salt, sugar, and saturated fat are at increased risk of having insufficient magnesium levels due to impaired absorption. (3

So, the question of how much magnesium you need if you fall into any of these categories still remains.  The answer isn’t so clear-cut.  Since blood magnesium level isn’t a good indicator of total body levels, and because this mineral is used in so many processes in the body, it is very difficult for researchers to pinpoint specific recommendations.

What foods have magnesium?

As with any nutrient, it’s always best to try and get what you need from food when possible.  Luckily, magnesium is easy to find in many whole, unprocessed foods, including:

  • Vegetables (spinach, swiss chard, okra, potatoes)
  • Nuts and seeds (pumpkin seeds, almonds, cashews)
  • Whole grains (bran, brown rice, oatmeal)
  • Beans and lentils (soy, black beans, black eyed peas)
  • Fruit (bananas, avocados)
  • Fish (halibut, yellow fin tuna)
  • Dairy

What are the Signs of Magnesium Deficiency

How can you tell if you have insufficient magnesium levels?  Since this mineral plays so many roles in the body, insufficient levels can show up in any number of ways.  Many of the symptoms of magnesium deficiency can often appear similar to other health issues.  That said, here are some common signs to look out for (3):

  • Trouble sleeping
  • Mood changes, anxiety, or depression
  • Constipation
  • Muscle cramps
  • Muscle twitching
  • Weakness
  • Fatigue/decreased endurance
  • High blood pressure
  • Headaches and migraines
  • High blood sugar/insulin resistance

If you have any of these symptoms, talk to your healthcare provider to rule out any other underlying conditions that may be causing your issues.

Types of Magnesium Supplements

If you’re unable to meet your daily needs via diet, it may be necessary to take a supplement.  Magnesium, however, cannot be taken by itself and must be bound to another element.  You’ll find that there are multiple combinations available, so which is best?

In general, magnesium bound to organic elements are more easily absorbed by the body than magnesium bound to inorganic elements.  Organic elements include citrate, glycinate, threonate, aspartate, lactate, and chloride.  Magnesium oxide and magnesium sulfate are both inorganic.

Beyond how well they’re absorbed, the elements bound to magnesium impact the specific benefits provided by the supplement.  For example, magnesium threonate is known to have benefits for brain function, anxiety, and depression.  Magnesium glycinate helps with sleep.  Magnesium citrate helps with constipation, depression, and anxiety.  And soaking in magnesium sulfate (Epsom salts) helps ease muscle strain, abdominal cramps, and constipation.  

Running woman surrounded with bubbles listing 10 signs of magnesium deficiency

The established Tolerable Upper Intake Level (UL) for magnesium supplements is 350 mg in the U.S. (2) This number represents the maximum amount that can be taken without any likely adverse effects.  That said, magnesium supplements can sometimes cause uncomfortable side effects such as loose stools or diarrhea. 

If you think you might need magnesium supplements, talk to your healthcare provider to determine the best type and how much is appropriate.


Magnesium is involved in so many processes in the body that insufficient levels can cause any number of health issues.  Blood tests, however, do not adequately detect magnesium deficiency.  It is, therefore, important to monitor for symptoms.

Certain individuals are at higher risk of magnesium deficiency, including athletes, people with diabetes or digestive issues, and people who consume large amounts of coffee, soda, alcohol, salt, sugar, and saturated fat.

As with any nutrient, it’s best to get what you need from food when possible.  If, however, your diet is low in magnesium or you have any of the symptoms of insufficiency listed above, talk to your healthcare provider to see if a supplement makes sense for you.

For more nutrition and wellness information and tips for active women over 40, click here to join my Facebook group, Fit, Fearless, and Fed Women Run the World!

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