Magnesium is an essential mineral for our overall health, meaning it is required for normal body function and must be obtained from our diet or supplementation. Yet many people consume less than the recommended daily allowance (RDA) of magnesium, making magnesium deficiency one of the top micronutrient deficiencies in the United States.
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Magnesium and Health
About 50-60% of magnesium in our body is found in our bones, the other half is found in soft tissue such as muscle, and less than 1% is in our blood.
Magnesium is needed for many different roles and functions, including assisting in over 300 enzymatic reactions in our body. Magnesium helps regulate glucose levels and blood pressure, produce energy, form our DNA, RNA, and support detoxification. It also plays a role in the active transport of calcium and potassium ions across cell membranes, which is important to nerve impulse conduction, muscle contraction, and normal heart rhythm.
Bones
Magnesium is involved in bone formation and influences the activities of osteoblasts and osteoclasts. Magnesium also affects the concentrations of both parathyroid hormone and the active form of vitamin D, which are significant regulators of bone homeostasis. Several population-based studies have found positive associations between magnesium intake and bone mineral density in both men and women.
Skeletal Muscles
While most of us understand that electrolytes like sodium and potassium are essential for our muscles, magnesium is also needed to synthesize protein and help our muscles to contract and relax. Magnesium deficiency may contribute to muscle weakness and cramps.
Heart
Our heart is a muscle too. Not only is magnesium needed for our skeletal muscles, but also for our cardiac muscles to help our heart pump blood to all our organs and limbs efficiently. Magnesium deficiency may be associated with high blood pressure, heart health issues, and irregular heart rhythms such as atrial fibrillation.
Nerves
For nerve conduction to occur, magnesium transports potassium and calcium across our cell membranes. Magnesium deficiency may cause numbness and tingling in our extremities.
Mitochondria
Our mitochondria are the powerhouses of our cells to produce energy. Mitochondria also store magnesium and use this mineral to create ATP, which is our energy source. Magnesium deficiency may contribute to fatigue if our cells cannot efficiently produce energy.
How is Magnesium Absorbed & Eliminated
Magnesium comes from our food when it gets broken down in our stomach, then absorbed in our small intestines. The amount of magnesium in our blood is controlled by elimination from our kidneys.
RDA of Magnesium
The Recommended Dietary Amount (RDA) of magnesium per day is different for all stages of life and genders:
Infants
Birth-6 months: 30mg
Toddlers
7 months-1 year: 75mg
1-3 years: 80mg
Children
4-8 years: 130mg
9-13 years: 240mg
Teens (14-18 years)
Females: 360mg
Males: 410mg
Adults (19-50 years)
Females: 310-320mg
Males: 400-420mg
Older Adults (51+ years)
Females: 320mg
Males: 420mg
Magnesium Deficiency Signs & Symptoms
Common symptoms and disorders that may be associated with magnesium deficiency include:
- Anxiety
- Arrhythmias
- Constipation
- Fatigue
- High glucose/diabetes
- High blood pressure
- Migraines
- Muscle cramps/aches
- Nausea
- Numbness/tingling
- Seizures
- Weakness
Magnesium Deficiency Possible Causes
Medications, lifestyle factors, and gut health all have the potential to interact with magnesium supplements or affect magnesium serum levels.
Diuretics
Diuretics cause the kidneys to get rid of extra fluid in the body to decrease blood pressure. Therefore, magnesium can be excreted in the fluid.
Proton Pump Inhibitors (PPIs)
Prescription proton pump inhibitor (PPI) drugs, when taken for prolonged periods, can cause low magnesium levels. The FDA advises healthcare professionals to measure patients' serum magnesium levels before prescribing PPIs and to recheck magnesium levels periodically.
Asthma Medications
Theophylline may affect the metabolism and urinary excretion of magnesium, potentially impacting total magnesium levels in the body.
Atrial Fibrillation Drugs
Digoxin, a medication to help manage an irregular heart rate such as atrial fibrillation, can also affect magnesium levels. Digoxin reduces tubular magnesium reabsorption, and in patients with congestive heart failure, this interaction may be cumulative with other factors affecting magnesium levels (diuretics, diet, poor intestinal absorption)
Oral Contraceptive
Oral contraceptives (or birth control pills) can affect certain nutrients such as magnesium, selenium, zinc, B2, B6, B12, folate, Vitamin C, and Vitamin E. Research has shown total serum magnesium can be reduced after taking oral contraceptive pills. It is thought that the increased risk of blood clots on oral contraceptive pills is partially due to the change in the calcium to magnesium ratio.
Exercise
We lose electrolytes such as sodium, potassium, chloride, and magnesium when we sweat. Most sports drinks containing electrolytes have sodium and potassium but not magnesium. Therefore, we must consider replenishing magnesium levels through food or supplements.
Diet
Those who eat a Standard American Diet may have lower magnesium intake. Alcoholism can also affect magnesium levels.
Stress
When we are under acute stress, our bodies use magnesium to release certain neurotransmitters and hormones, such as catecholamines, cortisol, corticotropin-releasing factor (CRF), and ACTH.
These neurotransmitters and hormones help our bodies to adapt to stress. However, if the stress continues after an acute event, our bodies will continue to release these chemicals and need magnesium. This can contribute to magnesium deficiency over time.
Gut Health
Because magnesium is absorbed in our small intestines, maintaining proper gut health is very important.
Reduced levels of many nutrients are prevalent in untreated celiac disease (CD) and Crohn's patients.
8 Different Types of Magnesium
Supplementing is an option to consider for replenishing magnesium in the body if we cannot get enough from our food. To understand which type of magnesium might be suitable for different needs, we have reviewed the most commonly used forms of magnesium below.
Magnesium Citrate
Magnesium citrate is a form of magnesium that's bound with citric acid. It is one of the most bioavailable forms of magnesium that is easily absorbed in the intestines. This form may have mild laxative effects; therefore, it can be helpful for those who experience constipation.
One study suggested that migraine sufferers' frequency was reduced by 41.6% when the participants took magnesium citrate.
Highlights: It's mainly used to support magnesium levels and may help with constipation in higher doses.
Magnesium Glycinate
Magnesium glycinate is made from a combination of magnesium and the amino acid glycine. This form of magnesium is easily absorbed and may have calming properties. It is also one of the gentlest magnesium supplements on the stomach and usually doesn't cause gastrointestinal distress associated with other magnesium types.
Glycine is often used as a standalone dietary supplement to support sleep.
Practitioners may use magnesium glycinate to help support magnesium levels and promote relaxation and stress management.
Highlights: Easily absorbed, used to support magnesium levels, and may have a calming effect.
Magnesium Oxide
Magnesium oxide is a salt that combines magnesium and oxygen and is the most common type of magnesium produced and used in supplements but has poor absorption.
It is often used to help manage constipation, so it should not be taken if you have loose stools or diarrhea. It is also frequently used for short-term relief of uncomfortable digestive symptoms, such as heartburn and indigestion.
Highlights: Mainly used for constipation. Not suitable for significantly raising magnesium levels due to poor absorption.
Magnesium Chloride
Magnesium chloride is a magnesium salt that includes chlorine and is easily absorbed via the digestive tract to support magnesium levels or, topically, to help with discomfort. One study suggested women with fibromyalgia experienced improvements after using magnesium chloride.
Highlights: Easily absorbed orally and topically. It is commonly used to support magnesium levels and manage digestive complaints such as heartburn and constipation. Topically it may help with discomfort but is not proven to increase magnesium levels this way.
Magnesium Malate
Magnesium malate includes malic acid, which occurs naturally in some foods like fruit and wine. This acid has a sour taste and is often used as a flavor enhancer.
Magnesium malate has excellent absorption and can support magnesium levels in our red blood cells. It is gentler on digestion than some of the other magnesium supplements. Therefore it is commonly used with individuals who already have a tendency towards looser stools.
This form of magnesium is occasionally recommended as a supportive option for symptoms associated with fibromyalgia and chronic fatigue syndrome, although there is limited research on this. This smaller study suggested a reduction in discomfort and tenderness in 24 individuals with fibromyalgia.
Highlights: Easily absorbed and gentler on digestion than other forms. It's occasionally recommended for chronic discomfort conditions.
Magnesium Orotate
Magnesium orotate is a combination of magnesium and orotic acid. It is easily absorbed because it is not broken down by our stomach acid. This type of magnesium supports magnesium levels and may help with symptoms of heartburn and indigestion related to higher stomach acid levels. It has also been shown to have heart health-supporting properties. A downside to magnesium orotate is its cost, as it is significantly more expensive than other magnesium supplements.
Highlights: Easily absorbed and used to support magnesium levels and heart health. Commonly used in athletes, but it is more expensive than other forms of magnesium.
Magnesium Sulfate
Magnesium sulfate is formed by combining magnesium, sulfur, and oxygen. It is commonly used as an Epsom salt soak. It can be taken internally to help manage constipation but has an unpleasant taste. Therefore many people choose other forms of magnesium to address constipation, like magnesium citrate.
Highlights: Although many people use this type of magnesium topically, there is little evidence that it is absorbed at high enough levels through the skin to significantly raise blood serum magnesium levels. Therefore, this form is commonly used to help with discomfort and relaxation.
Magnesium Taurate
Magnesium taurate is a combination of magnesium and the amino acid taurine. This form of magnesium has excellent absorption and is sometimes used to support blood pressure, preeclampsia in pregnant women, and insulin sensitivity, although human trials are limited.
Highlights: Not the most common magnesium supplement on the shelves, but there is a small amount of evidence that it may support conditions associated with blood pressure and insulin sensitivity. More trials have been requested for these conditions.
Functional Medicine Labs to Detect Magnesium Deficiency
It can be hard to determine if you have magnesium deficiency based on symptoms alone. Therefore, functional medicine suggests testing for magnesium and other micronutrient levels annually. Checking your levels can help determine how much magnesium you need every day and whether those levels can be achieved via diet or if a higher dose in supplement form is required.
Magnesium RBC
Most primary care providers check a serum magnesium level. The serum contains plasma, platelets, and red blood cells. Remember, less than 1% of magnesium is found in our blood because our cells get magnesium from our red blood cells. Therefore, the Magnesium RBC test is a more accurate assessment of the amount of magnesium detected in your red blood cells.
Micronutrient Testing
Functional lab tests such as the NutrEval by Genova Diagnostics check Magnesium RBC and other nutrient levels that could affect magnesium absorption.
Summary
Since many people may not get enough magnesium, which can be a factor in various health concerns, it is important to get your levels checked. Consuming more avocados, beans, nuts, whole grains, seeds, and salmon are excellent sources of magnesium in our food.