Magnesium, magnesium everywhere but not inside me!

Updated 12/6/2024

Magnesium is found pretty much everywhere – it’s the fourth most abundant element in the earth as a whole and the ninth in the universe as a whole. It’s highly water-soluble and is the third most common element dissolved in seawater.

But did you know that dietary surveys consistently show that the majority of Americans are eating less than the recommended amount of magnesium from food? In fact, the average U.S. adult falls well short of the recommended 400 mg per day and consumes only 266 milligrams of magnesium from food. This shortfall is likely due to a diet high in processed foods, as well as widespread soil mineral depletion.

It’s quite likely that magnesium was fairly abundant in our diets when the majority of the soil was enriched with composted materials, rather than just a few minerals as is generally done now (and magnesium isn’t one of those minerals).   Also, because it’s one of the minerals dissolved in spring water (which city water is not likely to have), it may have been drunk in abundance every single day.

Why is magnesium so important?

Magnesium is involved in almost every process that your body does, from muscle relaxation and proper muscle movement to hormone processing.   It regulates muscle and nerve function, blood sugar levels, and blood pressure.  It’s also involved in making protein, bone, and DNA.

Magnesium is central to all of our energy-forming reactions in every cell in the human body and there are over 300 enzyme pathways in humans that are dependent on magnesium to run.

What could happen if I am low or deficient in magnesium?

Scientists are studying magnesium to understand how it affects our health. Here are some examples of what this research has shown thus far:

High blood pressure and heart disease

High blood pressure is a major risk factor for cardiovascular disease and stroke. Magnesium supplements might decrease blood pressure, but only by a small amount. Some studies show that people who have more magnesium in their diets have a lower risk of some types of heart disease and stroke. In many of these studies, it’s hard to know how much of the effect was due to magnesium as opposed to other nutrients, however.

Type 2 diabetes

People with higher amounts of magnesium in their diets tend to have a lower risk of developing type 2 diabetes. Magnesium helps the body break down sugars and might help reduce the risk of insulin resistance (a condition that leads to diabetes). Scientists are studying whether magnesium supplements might help people who already have type 2 diabetes control their disease.

Osteoporosis

Magnesium is important for healthy bones. People with higher intakes of magnesium have a higher bone mineral density, which is important in reducing the risk of bone fractures and osteoporosis. Getting more magnesium from foods or dietary supplements might help older women improve their bone mineral density.

Migraine headaches

People who have migraine headaches sometimes have low levels of magnesium in their blood and other tissues. Several small studies found that magnesium supplements can modestly reduce the frequency of migraines. However, people should only take magnesium for this purpose under the care of a healthcare provider.

Yikes!  I need magnesium!  What foods can I get it from?

Magnesium is the center of the chlorophyll molecule in plants, so any dark green plant is a very rich source.  But it’s also found in MANY other foods, as you can see from the chart below.

Some of these foods, like magnesium, are also great for digestion, which is what I’m all about!  One little-known herb (or is it a vegetable?) that I’d like to highlight is fennel.  You can eat all parts of fennel and it has long been used to support digestion and decrease bloating, maybe because it shortens transit time, which is how quickly food passes through the digestive tract.  It’s easy to grow too, and Happy DIY Home has a great planting and harvesting guide!   You can use fennel in recipes ranging from teas to sausages to Greek foods, or just chew on the seeds!

What factors contribute to magnesium deficiency?

One of the most common reasons for magnesium deficiency is high blood sugar and diabetes. Obesity is also related to magnesium deficiency, and it’s currently thought to be the result of high blood sugar.

Unfortunately, the relationship between low magnesium and high blood sugar is a vicious cycle—a diet low in magnesium-rich foods tends to lead to poor blood sugar control. In turn, poor blood sugar control further lowers magnesium levels in the body. To break up this unwanted sequence of events, it is recommended to eat green vegetables, legumes, and properly soaked whole grains, or other good sources of magnesium.

Diuretics can either increase or decrease the loss of magnesium through urine, depending on the type of diuretic.  Prescription drugs used to ease symptoms of acid reflux or treat peptic ulcers can cause low blood levels of magnesium when taken over a long period of time.  Also, high doses of zinc supplements can interfere with the body’s ability to absorb and regulate magnesium.

Too high or too low protein intake can reduce magnesium absorption, so keeping protein intake moderate, or right for your needs, is best.

Also, phytates, found is nuts, seeds, and whole grains and interfere with magnesium absorption as well.  I’m not saying you shouldn’t eat these foods, because phytates are also very good for us, as they have been linked with improving blood glucose and lipids and may have anti-cancer properties.  But, if you are low in magnesium when all other factors indicate that your levels should be really good, you might consider consuming phytate-containing foods at a different time than magnesium-rich foods or supplements.

What factors affect magnesium absorption?

Food interactions

Magnesium, calcium, and phosphorus have a complex relationship with respect to absorption in the intestine. How much of each of these nutrients goes into the bloodstream versus being lost in the stool is variable by the relative amount, hormonal balance, and even by the time of day!

In general, more magnesium tends to reduce phosphorus absorption. This is not usually a problem because the average U.S. diet has plenty of phosphorus.

The relationship between calcium and magnesium, however, has been a topic of research for many years. Scientists have long been aware that these two minerals belong to the same family of elements (alkali earth metals), take on the same electrical charge (2+), and have a predictable ratio in different types of soil.

However, only in recent studies have scientists learned more about specific details concerning calcium and magnesium in terms of dietary intake and absorption rate.

It turns out that absorption of magnesium from our intestine depends not only on the amount of magnesium that is present but also on the amount of calcium that is present.  This is because the cells lining our intestine have a single spot (called the CaSR receptor) for absorbing these minerals, so basically they compete with each other.  Therefore, it is recommended to have a 2.5 to 1 ratio of calcium to magnesium.

But who wants to go around figuring out the amount of calcium and magnesium in every single food they eat to keep it in the right ratio?  Not me!

Thankfully, it has been figured out that most Americans consume far less magnesium than calcium.  And since Americans are barely consuming enough calcium, the recommendation is to increase magnesium rather than decrease calcium.  Many magnesium-rich foods (such as leafy greens) also contain calcium, but never fear–it’s naturally in the right ratio!

Medication interactions

Bisphosphonates, used to treat osteoporosis, are not well absorbed when taken too soon before or after taking dietary supplements or medications with high amounts of magnesium.

Antibiotics might not be absorbed if taken too soon before or after taking a dietary supplement that contains magnesium.

Can I get too much magnesium?

The risk of dietary toxicity from magnesium for healthy adults is very low. However, too much magnesium from supplements has been linked to loose stools.   Because of this low risk, the Institute of Medicine (IOM) at the National Academy of Sciences has established no upper limit for dietary intake of magnesium.

People with renal failure, especially if they are on dialysis, will need to work with a trained nutrition specialist to obtain safe recommendations about magnesium intake. The recommendations on this site are not appropriate for patients on dialysis.

Should I supplement with magnesium?

Because most people are deficient in magnesium, and because it’s quite easy for people to tell if they have gotten too much magnesium from a supplement (loose stools) and need to cut back, I usually recommend a magnesium supplement unless a person can prove that they don’t need one, either by dietary intake or a blood test (red blood cell magnesium so you’ll know how much is actually getting inside your cells).

Which type of magnesium supplement is best for me?

In order to be absorbed, magnesium needs to be bound to something.  Whatever it is bound to is what we call the different forms of magnesium, and each form is useful for different things.

Magnesium Citrate

Magnesium citrate is one of the most popular and easily absorbed magnesium supplements. In this form, magnesium is bound to citric acid, a large molecule, so there is a smaller amount of elemental magnesium per capsule. Because citric acid is a mild laxative, magnesium citrate is a great choice for individuals with occasional constipation.

Magnesium Oxide

Magnesium oxide is one of the least absorbed forms, but because the oxide molecule is small and compact, it delivers one of the highest percentages of elemental magnesium per dose, making it an effective choice for someone who wants to take as few capsules as possible. Because it is not as quickly absorbed in the intestine, magnesium oxide has more osmotic (water-attracting) effects in the colon, making it my favorite choice for those with occasional constipation.

Magnesium Glycinate

Magnesium glycinate is a gentle form for individuals who are sensitive to magnesium oxide or citrate, as it is less likely to cause a laxative effect. In this form, magnesium is bound to glycine, a non-essential amino acid involved in protein synthesis and transmission of chemical signals in the brain. Glycine is considered a relaxing neurotransmitter and may enhance magnesium’s natural calming properties. This could be one of the best types for those who want to promote mental calm, relaxation and good quality sleep.

Magnesium Gluconate

Another form of magnesium making the rounds for supplement shoppers these days is magnesium gluconate.  Magnesium gluconate is a form of magnesium often used medically to treat low blood magnesium caused by prolonged vomiting or diarrhea, kidney disease, gastrointestinal problems, or other conditions. (1)

Gluconate is one of the best-absorbed types of magnesium, useful for supplementing a magnesium-deficient diet, and the only form of magnesium recommended for supplementation according to the National Library of Medicine. (2)  Magnesium gluconate has shown promising results for preventing pregnancy-induced hypertension and premature contractions as well as supporting relaxation. (2)

Side note:

Both magnesium glycinate and gluconate are considered to to be well tolerated and beneficial for supplementing a magnesium-deficient diet.  The difference between the two forms of magnesium are their compounds. Magnesium glycinate includes an amino acid known as glycine, while magnesium gluconate contains gluconic acid, a natural compound that is noncorrosive, nontoxic, and less irritating than other acids. Though harder to find, current research suggests that magnesium gluconate is the most bioavailable and well-tolerated form of magnesium, making it a good choice when shopping for magnesium supplements.

Magnesium Malate

Another gentle form for those sensitive to magnesium oxide or citrate is magnesium malate. It is often recommended for people suffering from fatigue and symptoms of fibromyalgia since malic acid – a natural fruit acid present in most cells in the body – plays a key role in ATP synthesis and energy production.

Magnesium Taurate

This is a less common form and is typically taken for cardiac conditions and heart function in general. Magnesium helps the heart muscle relax, as well as the blood vessels that feed the heart to open and deliver more blood to the heart tissue itself. Taurine is an amino acid that is known to feed cardiac muscle and enhance the quality of contractions of the heart so if you’re taking magnesium for heart function this is probably the best form for you.

Magnesium Sulphate and Magnesium Chloride

These forms are both typically used topically, although there are some oral preparations as well. Magnesium sulphate is best known as Epsom salts. If you’ve taken this internally you know it tastes horrible and has a very strong laxative effect, but when used in a bath or soak it is extremely relaxing to the muscles and can ease aches and pains. Epsom salts baths can also help to lower high blood pressure and reduce stress levels.

Magnesium chloride is more common in the lotion, gel and oil preparations that are used topically for muscle cramps and relaxation.

Magnesium L-threonate

A newer player on the magnesium front is magnesium threonate, or magnesium L-threonate. This form effectively crosses the blood-brain barrier and so has recently been studied for uses such as patients with Alzheimer’s disease and other forms of cognitive decline.  A recent research study published in the medical journal Neuron showed that magnesium threonate creates improvement in learning abilities, working memory and both short and long-term memory.  Additionally, it has the same benefits as any other magnesium including enhancing sleep quality.

In summary, choosing the appropriate form of magnesium is a balance between the desired dose of elemental magnesium, how many capsules you are comfortable taking, and understanding any wanted or unwanted effects the mineral may have on the digestive system.

Where to Find Quality Magnesium Supplements

If you’re looking for high-quality magnesium supplements or other trusted wellness products, I’ve got you covered through my Fullscript online dispensary. It’s an easy way to access practitioner-recommended supplements that meet my standards for quality and effectiveness. Plus, it’s convenient and ships directly to your door. You can find everything you need to support your health goals in one place. Check it out my Fullscrip online dispensary here: https://us.fullscript.com/welcome/sgleaton/store-start

References:

1. Magnesium Gluconate. Medline Plus. October 2016. https://medlineplus.gov/druginfo/meds/a601072.html
2. National Center for Biotechnology Information (2023). PubChem Compound Summary for CID 71587201, Magnesium gluconate. Retrieved October 9, 2023 from https://pubchem.ncbi.nlm.nih.gov/compound/Magnesium-gluconate