By Danielle MacDowell
Main Takeaways
- Magnesium is involved in over 300 enzymatic reactions in our body, including reactions related to metabolism, DNA and protein synthesis, and activation of vitamin D.
- The function of magnesium spans beyond its enzymatic roles. It is also necessary for bone structure integrity, vascular health, chemical signaling, and blood-glucose control.
It is estimated that at least 40% of Americans are deficient in magnesium. However, due to insensitive assessment tools, an arguably high reference range, and the bodies’ strong compensatory measures, this percentage may be underestimated.
Inadequate diet, alcoholism, malabsorptive disorders, medications, parathyroid and thyroid conditions, severe burns, uncontrolled diabetes, and metabolic conditions can impair magnesium levels in the body. - The Recommended Daily Allowance (RDA) for magnesium varies and is based on age and gender. Pregnancy and lactation will increase magnesium need in the body.
- The best sources of dietary magnesium are cooked halibut, cooked spinach, dried almonds, dry roasted cashews, and mixed nuts. However, magnesium is contained in a number of additional food sources, including chocolate, coffee, lentils, dairy, bananas, oats, and avocados, to name a few.
- Eating protein, carbohydrates, and vitamin D may increase absorption of magnesium, while unabsorbed fatty acids, phosphorus, and phytic acids may interfere with absorption.
Table of Contents
Magnesium. Many of us have heard of this mineral but know very little about its function in the body. I remember my first introduction to magnesium. I was at a restaurant in New York City when one of my girlfriends took out a single-serving packet of magnesium and poured it into her tea. I was instantly intrigued by the contents of this little package. After all, my friend was choosing a beverage comprised of herbal tea and magnesium over the delicious red wine sitting on our table. She then went on to explain to me that she took it every night before bed to wind down and to help her sleep.
Since that dinner years ago, magnesium has gained a higher profile in the health and wellness sphere. I have seen a number of health claims about magnesium, most of them centered around anxiety reduction, depression, sleep improvement, and injury recovery. After learning about the importance of magnesium and discovering that a large percentage of Americans are deficient in magnesium, I decided it was a mineral worthy of some more attention.
8 Reasons Magnesium is Critical For Your Health
Let’s talk about why magnesium is important for you. There are several critical functions that magnesium is either responsible for or plays a role in. These can be categorized by enzymatic roles and non-enzymatic roles.
Enzymatic Roles of Magnesium in the Body:
Enzymes are involved in almost every reaction within our body. Every second, our body is carrying out massive amounts of chemical reactions. Without enzymes, our bodies would not be able to sustain the pace needed to fulfill these reactions with the efficiency necessary to keep us alive.
Enzymes are predominantly made up of proteins. Many require additional compounds, called cofactors, to carry out their functions. Cofactors are non-protein molecules, such as vitamins and minerals, that facilitate enzyme activity.
Magnesium is a major cofactor and is involved in over 300 enzymatic reactions in our body, including reactions related to metabolism, DNA and protein synthesis, and activation of vitamin D.
Magnesium-Dependent Enzyme Functions:
Fat, Protein, and Carbohydrate Metabolism: Our bodies require magnesium-dependent enzymes to metabolize carbohydrates, fats and proteins. In other words, in order for us to get energy from the food we eat, we need magnesium. This is why a magnesium deficiency can leave us tired and weak.
DNA Synthesis: DNA is our bodies’ blueprint; it dictates every aspect of our body, including how our body functions. Without magnesium, our bodies would not be able to create DNA nor maintain DNA’s physical integrity.
Protein Synthesis: Our body is quite efficient and resourceful, as it consistently repurposes and recycles raw materials to generate new compounds and molecules. One example of this is protein synthesis.
When we eat protein, it gets broken down into small structural units called amino acids. With the assistance of magnesium-dependent enzymes, these amino acids are then reorganized and re-used to make new proteins.
Without sufficient levels of magnesium, our body would have a difficult time generating new proteins. Considering nearly every structure in our bodies is made up of protein, a magnesium deficiency can result in extensive negative health consequences.
Activation of Vitamin D: Vitamin D can be obtained from supplements, the sun, and food. However, when it enters our body, it is inactive and needs to complete a series of steps in order to be converted into its bioavailable form(calcitriol).
Think about an ATM card. Until the card is activated, it cannot be used to make purchases. The same is true for vitamin D, until it undergoes the necessary activation steps, it is unable to fulfill its roles in the body. Magnesium is needed for this activation process.
Magnesium is involved in over 300 enzymatic reactions in our body, including reactions related to metabolism, DNA and protein synthesis, and activation of vitamin D.
Non-Enzymatic Roles of Magnesium in the Body:
As we saw above, magnesium plays a critical role in much of the enzymatic activity necessary to create and sustain life. However, the functions of magnesium span beyond these enzymatic roles. It is also necessary in bone mineralization, vascular health, chemical signaling, and blood-glucose control.
Bone Mineralization: Your bones are constructed from a number of minerals, including magnesium, phosphorus, and calcium. Although calcium is typically in the limelight when speaking about bone health, magnesium also deserves its due attention, as it is needed to develop and maintain our bone structure. When magnesium is out of balance (either too low or too high), bone integrity may be compromised making people more susceptible to fractures and osteoporosis.[1]
Blood Clot Prevention: Healthy blood clotting stops excessive bleeding when a blood vessel is damaged. However, blood clotting is not always a good thing. Blood clots formed under the wrong conditions can lead to a heart attack or stroke. Magnesium helps to keep harmful blood clotting under control.[2]
Mineral and Electrolyte Transport: Magnesium helps control minerals and electrolytes, such as sodium and calcium, enter and leave cells throughout your body. This transportation process happens through specialized cell channels and is necessary for muscle contraction, nerve conduction, and healthy blood pressure and heart rhythm.
All this to say, maintaining adequate magnesium levels is important for heart health, muscular output, and nervous system functioning.
Insulin Synthesis & Signaling: Insulin is a hormone produced and secreted by our pancreas in response to eating glucose. Insulin acts as a shuttle, delivering glucose to our cells. Magnesium plays a role in the generation and release of insulin,[2] which is likely why magnesium deficiency is implicated in a number of metabolic disorders such as hyperinsulinemia, type 2 diabetes, and metabolic disorder.
At this point, you are probably wondering what magnesium isn’t involved in! The answer is “not much”. It has a hand in almost every function in your body, either directly or indirectly. So, the fact that the many of us are deficient in magnesium is quite disconcerting. Wouldn’t you agree?
The function of magnesium spans beyond its enzymatic roles. It is also necessary to maintain bone structure, vascular health, chemical signaling, and blood-glucose control.
Magnesium Deficiency
It is estimated that at least 40% of Americans are deficient in magnesium. [3] However, due to insensitive assessment tools, an arguably high reference range, and the bodies’ strong compensatory measures, this percentage may be underestimated.[2]
Magnesium Assessment Tools
Ninety-nine percent of our magnesium is housed in our bones, muscles, and soft tissue, making it a difficult mineral to assess accurately. The remaining 1% of magnesium is in the fluid that surrounds our cells (extracellular fluid) and this magnesium is tightly regulated.[2-4]
Our bodies want us to keep a certain level of magnesium in our extracellular fluid so it can fulfill various roles within the body. So, when extracellular magnesium levels drop beyond a certain threshold, magnesium will be extracted from the bone to replenish the mineral supplies in the serum.
Our body is virtually robbing Peter to pay Paul. However, we don’t have the tools to detect this compensation adequately, which is one reason magnesium deficiency may go undetected. For this reason, it is especially important to be attuned to your diet, aware of the underlying causes of magnesium deficiency, and familiar with symptoms of magnesium inadequacy so that you are able to do your best to obtain and maintain adequate levels of magnesium in your body.
In the realm of magnesium assessment, utilizing several tests to measure magnesium levels will help paint the clearest picture of magnesium status. Some available options are serum, red blood cells, hair, urine, and magnesium loading.
Due to insensitive assessment tools, an arguably high reference range, and the bodies’ strong compensatory measures, magnesium deficiency in the general public may be underestimated. Utilizing several tests to measure magnesium levels will help paint the clearest picture of magnesium status. There are a number of assessment methods available to test magnesium levels, such as serum, red blood cells, urine, hair analysis, and magnesium loading tests via urine analysis.
Magnesium Recommended Dietary Intake (RDA)
While slight magnesium deficiency may be difficult to discern, evaluating your diet may serve as an indicator of your magnesium status. Keep in mind that a diet assessment is only an indicator. Just because you are consuming magnesium, it doesn’t mean your body is actually absorbing it and/or holding onto it. For example, if you have any conditions that cause diarrhea or vomiting, you are more susceptible to a magnesium deficiency because your body is excreting magnesium at higher rates than normal.
Before moving forward, it is important to know how much magnesium you should be consuming. Like many vitamins and minerals, the recommended daily allowance (RDA) is dependent upon age and gender as well as pregnancy and lactation status.
For example:
An adult male between the ages of 19-30 years old should strive for 400 mg of magnesium a day, while a female between the ages of 19-30 years old should consume 310 mg of magnesium a day.[5]
Males over 31 years old should aim for 420 mg of magnesium a day and females over 31 years old should obtain 320 mg of magnesium a day.[5]
Keep in mind that pregnant women, children, infants, and teenagers will all have different requirements than those mentioned above. For more information on RDA, you can visit: https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/#h2.
Tracking Magnesium Intake
If you do choose to move forward with the diet examination, I recommend using a nutrient tracker on your phone; it’s a pretty efficient and relatively reliable way of tracking your intake. If you take any multivitamins, magnesium supplements, or magnesium-containing over-the-counter medications, such as laxatives and antacids, don’t forget to also add these into your tracking tool so you can get an accurate intake.
When tracking or trying to beef up your magnesium intake, it will be helpful to have a handy list of magnesium-rich foods. Fortunately, magnesium can be found in a variety of sources, including two of my favorite items: dark chocolate and coffee!
Magnesium Food Sources
Magnesium-rich food sources include:
- Fish & Seafood (e.g. halibut, oysters, cod)
- Cooked Legumes
- Green leafy vegetables (e.g. spinach)
- Nuts & Seeds
- Dark chocolate (the higher the percentage of cacao the better!)
- Dairy
- Whole-grains
- Coffee
Although this list does include some of the richer sources of magnesium, it is certainly not exhaustive. Some additional examples of foods you can obtain smaller amounts of magnesium from, as compared to the list above, include broccoli, bananas, avocado, potatoes, oatmeal, and blackstrap molasses. For a more extensive list, visit https://fdc.nal.usda.gov/
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Best Sources of Magnesium: You might be wondering what the best sources of magnesium are. Believe it or not, cooked halibut is one of the top sources of magnesium.2 Three ounces of the cooked fish contains 90 milligrams(mg) of magnesium.
If seafood doesn’t suit your palate, don’t get dismayed because there are some close contenders to halibut, including almonds (1 ounce=80 mg), spinach (½ cup= 78 mg), and roasted cashews (1 ounce= 74mg).
Example of Magnesium-Rich Meal:
3 ounces cooked halibut (90mg)
½ cup spinach (78mg)
½ cup cooked lentils (35mg).
This meal puts you at 203 mg magnesium, covering a portion of an adult’s daily needs.
The best sources of magnesium are cooked halibut, cooked spinach, dried almonds, dry roasted cashews, and mixed nuts. However, magnesium is contained in a number of food sources, including chocolate, coffee, lentils, dairy, bananas, oats, and avocados, to name a few.
Causes of Magnesium Deficiency
Unfortunately, consuming enough magnesium doesn’t always ensure that we are actually absorbing and maintaining enough magnesium in our body. Gropper [2] describes several causes of magnesium deficiency, including:
Inadequate diet: A common problem with the standard American diet is that it does not contain adequate vitamins and minerals. Magnesium is not exempt from this statement.
It is suspected that at least 40% of Americans are deficient.[3] For this reason, it is important to intentionally include adequate amounts of magnesium in your diet so your body can perform all of the important functions mentioned above.
Regular Alcohol Consumption: Alcohol use has been associated with decreased magnesium consumption and increased urinary excretion. Magnesium loss is directly associated with diarrhea and vomiting, which is a potential reason for this connection. Additionally, the diuretic effect of alcohol may contribute to increased urinary excretion.
So, for those who drink alcohol regularly, it will be even more critical to consider ways of maintaining magnesium levels.
Malabsorption: Magnesium is absorbed in the small intestines. However, malabsorptive disorders, such as Crohn’s disease, can interfere with this process, due to increased diarrhea and/or vomiting.
Interference from nutrients and antinutrients can also contribute to malabsorption.
High quantities of unabsorbed fatty acids: Unabsorbed fatty acids interfere with magnesium absorption.[2] This being the case, people with fat malabsorption disorders may have an even more difficult time obtaining adequate levels of magnesium.
Phytic acids: Phytic acids can also hinder your ability to absorb magnesium. Phytic acids are found in nuts, grains, and legumes. Many of these foods are good sources of magnesium, which makes this situation a bit tricky. One way to break down the phytic acids is to soak your nuts, grains, and legumes before eating. This process should allow you to get more magnesium in your body.
Phosphorus: When phosphorus and magnesium are consumed together, they tend to form an insoluble complex, making it nearly impossible to absorb, essentially “cancelling” these two minerals out.[2]
Medications: Medications, such as proton pump inhibitors and diuretics have been shown to interfere with absorption and increase urinary magnesium loss, respectively.[2]
Additional Causes for Magnesium Deficiency: Parathyroid and thyroid conditions, severe burns, uncontrolled diabetes, and metabolic conditions can also impair magnesium levels in the body.[2]
Inadequate diet, alcoholism, malabsorption, medications, parathyroid and thyroid conditions, severe burns, uncontrolled diabetes, and metabolic conditions can impair magnesium levels in the body. If a magnesium deficiency is suspected, it will be important to determine the root cause of the deficiency.
Signs and Symptoms of Magnesium Deficiency
At this point you have a good understanding of how to get your magnesium and factors that impede on your ability to absorb and maintain magnesium. Let’s take a look at signs and symptoms that you may experience if you actually have a deficiency.
At the beginning stages of a magnesium deficiency, most individuals are either asymptomatic or present ambiguous symptoms, making deficiency hard to detect. Patients begin to exhibit more perceptible signs of the deficiency once plasma concentrations drop below 1.2 mg/dL.2 However, diagnosable hypomagnesemia is considered to be below 0.76 mmol/L.4.
Some warning signs to look out for if you suspect a magnesium deficiency/insufficiency include:
- Nausea
- Vomiting
- Hypotension
- Weakness
- Fatigue
- Confusion
- Depressed heart
- Reduced respiration rate [2]
Increase Magnesium Intake
If magnesium levels are low, first and foremost, it will be important to determine the root cause. For example, if a malabsorption issue, caused by gastrointestinal issues, is the challenge, it will be important to focus on healing your gut. On the other hand, if the malabsorption issues are a result of anti nutrients, such as phytic acids, it would be wise to soak the nuts and beans before consumption. It is also a good idea to obtain your magnesium from a diverse array of foods. This will allow you to get a nice variety of other important nutrients in your diet.
If magnesium levels have not improved after you corrected the root cause, maximized absorption, and have eaten magnesium-rich foods for a period of time, supplementation is always an option. However, as with all things-supplement related, it’s important to run this option by your healthcare professional to make sure it is the right option for you. If you do choose to go the supplementation route, you can obtain your magnesium through magnesium salts, multivitamins, topical magnesium, or epsom baths.
If you do choose to go the supplement route, be mindful of your intake. It is unlikely for a healthy individual to overdose on magnesium from food.[2,5] However, individuals consuming non-food sources of magnesium, such as supplements, laxatives, and antacids, can accumulate a toxic load if they exceed the tolerable upper limit of 350 mg in non-food sources.[2]
Final Thoughts and Main Takeaways
Magnesium is involved in over 300 enzymatic reactions in our body, including reactions related to metabolism, DNA and protein synthesis, and activation of vitamin D. However, the function of magnesium spans beyond its enzymatic roles. It is also necessary for bone structure integrity, vascular health, chemical signaling, and blood-glucose control.
It is estimated that at least 40% of Americans are deficient in magnesium. However, due to insensitive assessment tools, an arguably high reference range, and the bodies’ strong compensatory measures, this percentage may be underestimated. Inadequate diet, alcoholism, malabsorptive disorders, medications, parathyroid and thyroid conditions, severe burns, uncontrolled diabetes, and metabolic conditions can impair magnesium levels in the body.
The Recommended Daily Allowance (RDA) for magnesium varies and is based on age and gender. Pregnancy and lactation will increase magnesium needs in the body. The best sources of dietary magnesium are cooked halibut, cooked spinach, dried almonds, dry roasted cashews, and mixed nuts. However, magnesium is contained in a number of additional food sources, including chocolate, coffee, lentils, dairy, bananas, oats, and avocados, to name a few.
Eating protein, carbohydrates, and vitamin D may increase absorption of magnesium, while unabsorbed fatty acids, phosphorus, and phytic acids may interfere with absorption.
- DiNicolantonio JJ, O’Keefe JH, Wilson W. Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. Open Heart. 2018 Jan 13;5(1):e000668. doi: 10.1136/openhrt-2017-000668. Erratum in: Open Heart. 2018 Apr 5;5(1):e000668corr1. PMID: 29387426; PMCID: PMC5786912.
- Gropper, S, Smith, J, Carr, T. Advanced Nutrition and Human Metabolism. 7th Edition. Boston, MA: Cengage; 2018.
- Lord R. Laboratory Guides to Health. 6th Edition. Arrowhead Bioscience; 2020.
- Uysal N, Kizildag S, Yuce Z, Guvendi G, Kandis S, Koc B, Karakilic A, Camsari UM, Ates M. Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best? Biol Trace Elem Res. 2019 Jan;187(1):128-136. doi: 10.1007/s12011-018-1351-9. Epub 2018 Apr 21. PMID: 29679349.
- National Institutes of Health. Magnesium. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/. Updates on September 25, 2020. Accessed on January 3, 2021.
