Magnesium Deficiency Signs, Symptoms and How to Fix It

By: Courtney Sperlazza, MPH
February 5, 2020

Magnesium Deficiency Signs, Symptoms and How to Fix It

  • Magnesium is involved in many body processes. This makes magnesium deficiency difficult to identify because it looks like a lot of other conditions.
  • Symptoms include heart arrythmias, depression, digestive problems, muscle spasms and more.
  • Low magnesium is caused by things like stress, medicines, alcohol consumption and certain medical conditions. Modern farming yields lower-magnesium plants than previous generations had.
  • Keep reading for common magnesium deficiency symptoms and the best ways to correct it.

It’s hard to pinpoint magnesium deficiency as the source of your troubles when the mineral is involved in so many seemingly unrelated functions in your body. Think about it: If you haven’t pooped in three days, you’re snapping at your kids and you keep losing your car keys, would you think that all of those trace back to the same thing — let alone low magnesium?

What’s more is that these symptoms aren’t always something doctors will treat. Constipated? Eat more fiber. For your temper, try meditation. If you’re forgetful, you’re told it’s all part of the normal aging process. In reality, a magnesium supplement might help all of this.

Related: The Top 10 Supplements That Everyone Should Take

Magnesium deficiency symptoms

Woman holding fingertips to temples

Magnesium deficiency is one of those things that tricks doctors. It looks like a lot of other conditions, since magnesium is involved in so many of your body’s processes. If you’re deficient, and 80% of people are, the effects range from mildly annoying to serious.[1] Here are the most common signs of low magnesium:[2] [3] [4] [5] [6]

  • Fatigue
  • Aches and pains
  • Mood problems
  • Muscle cramps
  • Migraines
  • PMS
  • Irregular sleep patterns and insomnia
  • Heart irregularities
  • Muscle twitches and spasms
  • Anxiety
  • Digestive trouble
  • Lack of appetite
  • Constipation
  • Brain fog
  • Memory problems
  • Depression
  • ADHD

The tricky thing is, you can have a magnesium deficiency and display some of these symptoms, but you may have no noticeable symptoms at all. From heart arrhythmias to major depression, ignoring the signs isn’t worth the gamble — especially when magnesium is one of the cheapest, most abundant supplements you can get.

Here’s how to find out if your symptoms are the result of a magnesium deficiency.

How to test for magnesium deficiency

Variety of pills

If you’ve tested your magnesium, chances are, you got the wrong test. Blood tests for magnesium aren’t the most accurate, since your body stores over half of its magnesium in the bones and soft tissues. So, you’ll need to test your intracellular magnesium levels, not your serum magnesium.

The test you want is called the magnesium RBC test. This test measures the amount of magnesium stored in your red blood cells, which gives you an indication of how much magnesium your body has in reserves in your bones and soft tissues.

Optimal magnesium range

If your results fall below 6.0 mg/dl, you’ll want to supplement. If they’re measured in mmol/L, multiply that number by 2.43 to get mg/dl, and see how close you are to 6.0. This is a functional level. Most labs report a “normal” range, but since everyone’s requirements can vary, work with your doctor to interpret your results.

It’s a good idea to check your vitamin D levels while you’re at it, since magnesium and vitamin D depend on each other for function and absorption. Or, you can go ahead and supplement vitamin D now because most people don’t get enough.

If you find out that you’re low on magnesium, keep reading for more information on how magnesium affects your body and the best way to handle each symptom.

The bottom line: The best test for magnesium deficiency is the magnesium RBC test. Consult with your doctor to determine whether the results are “normal” for you. Oh, and take vitamin D since it works with magnesium, and you’re likely deficient.

Magnesium for mood, concentration and sleep

Green brain on gray background

Regulation of moods, how clearly you think and how well you sleep all happen in the brain. On the microscopic level, you can see an intricate network of electrical wires in your neural tissues. Your brain works and communicates through teeny electrical impulses, firing all day, every day.

Wavering moods, mental clarity, attention problems and anxiety seem like distinct conditions, but they all have a common thread: They signal that the mitochondria (the structures that power your cells) in your brain are struggling.

Turns out, the availability and balance of magnesium determines how much energy your mitochondria make.[7] The available energy in your brain determines how clearly you think, how intensely you can focus, how calm or anxious you feel, how happy you feel and how you respond to stress. Having adequate amounts of magnesium will help regulate all of these issues.

The bottom line: A lack of magnesium can lead to low cellular energy in your brain, which can make you moody, foggy-brained and anxious.

Foods with magnesium for mood and memory

Stack of dark chocolate

Foods that contain magnesium along with tryptophan offer a dual-angle approach to enhancing mood and mental clarity. Tryptophan is a precursor to serotonin, the brain chemical that makes you feel happy, focused and calm. Foods that contain both magnesium and tryptophan include:

  • Dark chocolate
  • Spirulina
  • Salmon
  • Spinach
  • Nuts and seeds (sunflower seeds, cashews, flaxseed)
  • Bananas
  • Avocados

The bottom line: Tryptophan is a precursor to serotonin, which enhances mood and mental clarity. Eat foods with both tryptophan and magnesium to support your mood and get a mental boost.

Related: Blue Spirulina Latte Recipe

What you should know about magnesium, digestion and PMS

Your body relies on magnesium to regulate your bowels, detox your liver and eliminate and produce hormones. When these processes don’t happen like they should, you get some pretty gnarly symptoms.


Woman holding hands over stomach in bed

When you eat, your food mixes with saliva and stomach acid to form what’s known as a bolus, a semi-solid lump of food that moves through the digestive system. To move efficiently, it has to be soft, and to be soft, the bolus has to have sufficient water content. Magnesium draws water into the bowels and stimulates peristalsis, or the “waves” of muscle contraction that keeps everything moving.

Without enough magnesium, the bolus of food is dry and stiff, which slows everything down and causes constipation.[8]

The bottom line: Magnesium draws the water into your bowels that keeps your system moving. If you’re low on magnesium, you’ll likely experience constipation.

PMS from reabsorbed estrogen

Closeup of intestines

PMS points to an excess of estrogen. One of the main ways your body gets rid of estrogen is through the bowels. When your digestive system works well, your body produces and excretes estrogen at a good pace for your body. When things slow down with magnesium deficiency, estrogen hangs out in your intestinal tract too long.

Your intestinal membranes allow water, fats, and nutrients to pass through while they’re waiting for their exit. This is how your body gets nutrition out of food. Other things that are waiting for departure cross membranes, too, like toxic compounds and hormones. That’s why experts tell you to make sure you’re eliminating at least 1-2 times per day before you do a detox.

Whatever estrogen doesn’t leave the body in a timely fashion goes right back into the bloodstream, and stacks on top of the estrogen you’re producing per your regularly scheduled program.

If you’re constipated or have slow digestion because of low magnesium, you might also experience PMS relief by supplementing with magnesium.[9]

The bottom line: With enough magnesium to regulate digestion, excess estrogen is passed out of your body as it should. Without enough magnesium, your body becomes constipated and holds on to that estrogen — which can contribute to PMS symptoms.

PMS from affected liver function and hormone imbalance

A bunch of broccoli florets

Not only does magnesium help keep you regular, it is also crucial for detox in the liver, which also neutralizes excess estrogen.[10] In the liver, estrogen metabolites are converted to water-soluble molecules so you can get them out quickly. Without sufficient magnesium, this process slows down considerably.

Magnesium is also critical in your body’s production of sex hormones that balance estrogen, including progesterone and testosterone. On top of that, most sex hormones are manufactured when you’re snoozing and good magnesium levels improve sleep.

Increased magnesium in your diet will decrease constipation. Since fiber also helps with digestion, stay regular by eating vegetables like:

  • Spinach (lightly steam it first to reduce the lectin content)
  • Broccoli
  • Artichokes
  • Cabbage
  • Asparagus

The bottom line: Magnesium plays a role in detoxing the liver, producing all sex hormones and helping you sleep. This means it can reduce PMS from excess estrogen by enabling your liver to detox excess hormones, producing hormones that balance estrogen and helping you make more of those hormones while you sleep.

How magnesium impacts heart irregularities and muscle spasms

Illustration of red heart and blood vessels

Have you ever cramped up during a run, felt your eyelids twitching, or taken a gasp from fluttering in your chest? It’s all from nerve cells getting over-excited and firing too much.

How and when nerve cells fire depends entirely on electrolyte balance — the concentration of sodium and potassium ions on either side of the cell’s membrane. A portion of electrolytes switch places when the nerve cell fires. Magnesium steps in when there are imbalances. When there’s not enough magnesium available, there’s no stopping an over-excited neuron, and no waking up a lazy one.

Too much firing, and magnesium will slow down ion exchange. When there aren’t enough nerve impulses, magnesium will kickstart the exchange process.[11]

Every muscle in your body depends on magnesium to keep this system working properly. If you experience any of the following symptoms, you might need more magnesium for your nerves and muscles to play nicely together:

  • Heart irregularities, palpitations or “flutters”[12]
  • Muscle spasms[13]
  • Muscle cramping
  • Restless leg syndrome[14]
  • Twitching eyelids, lips, or skeletal muscle
  • Nightly leg cramps, especially in pregnancy[15][16]

Symptoms like these can have a root cause other than magnesium deficiency, and some conditions are serious and require medical attention. So, run your concerns by your doctor and discuss any changes you’re considering.

The bottom line: Magnesium balances the electrolytes in your cells. When you’re low on magnesium, your cells can malfunction, causing spasms in muscles in your heart, legs and even your eyelids.

Skeletal-muscular symptoms

Epsom salt on wooden spoon

Some forms of magnesium absorb through the skin, which makes topical magnesium effective for muscle relief. For muscle cramps or spasms, spray on magnesium oil, which isn’t actually oil at all. It’s magnesium chloride, which feels slippery because it’s slightly more basic than water.

Another topical solution: Take a bath with epsom salts, which are magnesium sulfate crystals. How much you’ll absorb depends on how deficient you are and your body’s other nutrient levels, particularly vitamin D. Pour 1-2 cups of epsom salts into your bath a couple times a week to get a boost, and drink plenty of water when you’re done soaking.

If you don’t have time for a bath, you can use a magnesium capsule supplement to address these symptoms

The bottom line: Your body can absorb magnesium through the skin. You can either use a magnesium spray, or the tried-and-true method of an epsom salt bath, which will give you an infusion of magnesium.

Why are so many people magnesium deficient?

Hand touching soil

Statistics depend on who you ask, but it is estimated that over 80 percent of people are magnesium deficient. Why so many?

You don’t get as much magnesium in your diet as your great-great-grandparents did. With mono-cropping and soil depletion, your vegetables don’t take up as many minerals from the soil as they used to.

Natural spring water used to be a reliable source of minerals, too, but it’s way more likely you’re drinking filtered water from a bottle or your fridge. If you have public water, more than likely it contains fluoride, which depletes magnesium even further.

The good news is, magnesium supplements are super cheap and easy to come by. Once you find the type that’s right for you, you can feel the effects fairly quickly.

The bottom line: Faster crop rotation (less time in the ground) and the chemicals added to our public water supplies are contributing to widespread magnesium deficiency. Up your magnesium intake to ensure you’re not included in the statistic.

Causes of magnesium deficiency

Bottle of pills next to glass of alcohol

If you’re magnesium deficient, you want to hang onto as much magnesium as you can. These things can work against you, depleting your body of magnesium:

  • Over-the-counter and prescription medicines: A wide range of medicines, like antacids, antibiotics, birth control pills, blood pressure medications, stomach acid blockers and more cut into your magnesium stores.[17]
  • Medical conditions: Crohn’s, kidney disorders, Celiac disease, any digestive disorder, diabetes, low stomach acid and many more affect magnesium absorption and retention.
  • Alcohol consumption: Occasional drinks are fine, but regular alcohol consumption destroys your mineral stores, especially magnesium.[18] You can tell drinking throws off your electrolyte balance because you wake up thirsty, puffy and bloated, all at the same time.
  • Stress: Stress kicks magnesium from the inside of your cells to the space outside your cells, which makes your kidneys excrete it faster.[19] If you have stress here and there, you have enough magnesium to recover. Chronic stress tanks your magnesium.

The bottom line: Medicine, medical conditions, alcohol and stress all are big contributors to magnesium deficiency.

Because magnesium regulates hundreds of processes in your body, it’s a mineral supplement worth looking into. Since it’s difficult to overdo magnesium (your bathroom habits will tell you when you’ve taken it too far), and because you’re likely to see results within a few days, magnesium is a safe supplement to experiment with to see if it helps you.

There are 10 or so more common forms of magnesium supplements on the market, and they don’t all treat the same symptoms. In general, women need about 320 mg of magnesium per day, and men need about 420 mg per day. Find out how to choose the right magnesium for your body.

Join over 1 million fans

Sign-up for the Bulletproof mailing list and receive the latest news and updates!