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Magnesium Benefits, Dosage Recommendations and Best Types

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Magnesium health benefits - Dr. Axe

Considering all of the important roles that magnesium plays in the body — and the fact that a magnesium deficiency is one of the leading nutrient deficiencies in adults, with an estimated 80 percent being deficient in this vital mineral — it’s a good idea to consider taking magnesium supplements regularly. Of course, this is in addition to eating plenty magnesium-rich foods.

What does magnesium do for the body, and why can it be detrimental to be deficient?

Magnesium — which comes from the obsolete root word magnes, which was used to mean magnet or magnetic power — may not be the most present mineral in our bodies in terms of its quantity, but it’s certainly one of the most crucial to overall health.

Magnesium is involved in over 300 biochemical functions in the body, such as regulating heartbeat rhythms and helping neurotransmitter functions, which is why hypomagnesemia (another name for magnesium deficiency) is something you really want to avoid.


What Is Magnesium?

Magnesium is an essential mineral and also an electrolyte. What is magnesium used for in the human body? Some of the main functions of magnesium include:

  • Regulating blood pressure
  • Keeping bones strong
  • Balancing nitric oxide in the body
  • Supporting growth and development in babies and children
  • Supporting proper function of nerves, muscles, and tissue
  • Neutralizing stomach acid
  • Moving stools through the intestine and preventing constipation
  • Magnesium also makes the process of photosynthesis possible by helping to form chlorophyll, the chemical that allows plants to capture sunlight and turn it into energy

The kidneys primarily control levels of magnesium within the body and excrete magnesium into the urine each day, which is one reason why urinary excretion is reduced when magnesium and other electrolyte statuses are low. Magnesium is actually the least abundant serum electrolyte in the body, but it’s still extremely important for your metabolism, enzyme function, energy production and much more.

Although we only need small amounts of magnesium relative to other nutrients, we must regularly replenish our stores, either from foods or magnesium supplements, in order to prevent deficiency symptoms. That’s because the body loses stores of magnesium every day from normal functions, such as muscle movement, heartbeat and hormone production.

Magnesium is naturally present in some foods, synthetically added to other food products, and available in dietary supplement form. Additionally, it’s found in some over-the-counter medicines, such as antacids and laxatives.

What foods are high in magnesium that we should be including our diets? Some of the best choices include dark leafy greens like spinach, beans, avocado and almonds. While it’s best to get as much of this mineral as you can from natural magnesium-rich food sources, magnesium supplements can also help some people who are prone to deficiency, such as older adults, athletes and anyone under a lot of stress.


Types of Magnesium Supplements

What does a magnesium supplement do for you? Because magnesium supplements pose little risk for side effects or toxicity, many health care professionals now recommend that adults take supplements regularly to prevent deficiency.

Magnesium supplements are available in a variety of forms. The absorption rate and bioavailability of magnesium supplements differs depending on the kind; usually types that dissolve in liquid are better absorbed in the gut than less soluble forms.

It’s believed that magnesium in citrate, chelate and chloride forms are absorbed better than magnesium supplements in oxide and magnesium sulfate forms.

Here’s information about the different types of magnesium supplements:

  • Magnesium Chelate — highly absorbable by the body and the kind found in foods naturally. This type is bound to multiple amino acids (proteins) and used to restore magnesium levels.
  • Magnesium Citrate — magnesium combined with citric acid. Magnesium citrate may have a laxative effect in some cases when taken in high doses, but is otherwise safe to use for improving digestion and preventing constipation.
  • Magnesium Chloride Oil — an oil form of magnesium that can be applied to skin. It’s also given to people who have digestive disorders that prevent normal absorption of magnesium from their food. Athletes sometimes use magnesium oil to increase energy and endurance, to dull muscle pain, and to heal wounds or skin irritation.
  • Magnesium Glycinate — highly absorbable, this is recommended for anyone with a known magnesium deficiency and less likely to cause laxative effects than some other magnesium supplements.
  • Magnesium Threonate — has a high level of absorbability/bioavailability since it can penetrate the mitochondrial membrane. This type is not as readily available, but as more research is conducted, it may become more widely used.
  • Magnesium Orotate — these supplements have orotic acid, and magnesium orotate is beneficial to the heart.

How do you know if you should use magnesium supplements? According to the National Institutes of Health (NIH), assessing magnesium levels is difficult because most magnesium is inside cells or bones and not within the blood. This can make blood test results misleading when it comes to determining a magnesium deficiency. The most common method for assessing magnesium status is by measuring serum magnesium concentrations in the blood or by measuring concentrations in saliva and urine, but no single method is considered totally comprehensive and accurate.

If you’re going to supplement, when should you take magnesium? The best time of day to take magnesium for most people is right before bed. It’s also a good idea to split doses, taking some in the morning and some at night, which can help with absorption.

Related: Magnesium Oxide: Effective Supplement or Poorly Absorbed?


Magnesium Deficiency

For many people, a magnesium deficiency — also known as hypomagnesemia, with “hypo” meaning under, “magnes” referring to magnesium and “-emia” meaning in the blood — causes at least some noticeable negative symptoms. These can include muscle aches or spasms, poor digestion, anxiety, and trouble sleeping.

Yet, magnesium deficiency is often overlooked and rarely tested. Therefore, magnesium may be one of the most underutilized but most necessary supplements there is.

What are the symptoms of low magnesium in the body?  Some of the most prominent magnesium deficiency symptoms according to the National Institutes of Health (NIH) include:

  • hypertension (high blood pressure) and cardiovascular disease
  • kidney and liver damage
  • peroxynitrite damage that can lead to migraine headaches, multiple sclerosis, glaucoma or Alzheimer’s disease
  • nutrient deficiencies, including vitamin K, vitamin B1, calcium and potassium
  • restless leg syndrome
  • worsened PMS symptoms
  • behavioral disorders and mood swings
  • insomnia and trouble sleeping
  • osteoporosis
  • recurrent bacterial or fungal infections due to low levels of nitric oxide or a depressed immune system
  • tooth cavities
  • muscle weakness and cramps
  • impotence
  • eclampsia and preeclampsia

Why is magnesium deficiency so common? A few factors are at play:

  • Soil depletion that lowers the amount of magnesium present in crops
  • Digestive disorders that lead to malabsorption of magnesium and other minerals in the gut
  • High rates of prescription medication and antibiotic use, which can damage the digestive tract to the point that magnesium cannot be absorbed and properly utilized from foods.

You’re most at risk for magnesium deficiency if you have: a liver disorder, heart failure, inflammatory bowel disease, frequent vomiting or diarrhea, kidney dysfunction, and other conditions that affect absorption. Older adults and women seem to be affected more often than younger adults and men.

Magnesium is connected to other nutrients within the body, including calcium, vitamin K and vitamin D. Experts believe that one of the reasons magnesium supplements are so beneficial is because they help counterbalance high levels of calcium that can accumulate in the body when people take calcium supplements regularly. Similarly, taking vitamin D in high levels, or being deficient in vitamin K2, can lower magnesium stores in the body and contribute to a deficiency.

Recommended Daily Allowance of Magnesium:

How much magnesium should you take per day? Keep in mind that magnesium needs vary on different individual factors, like your age and gender. According to the NIH, below are the current RDAs for magnesium:

  • Infants–6 months: 30 milligrams
  • 7–12 months: 75 milligrams
  • 1–3 years: 80 milligrams
  • 4–8 years: 130 milligrams
  • 9–13 years: 240 milligrams
  • 14–18 years: 410 milligrams for men; 360 milligrams for women
  • 19–30 years: 400 milligrams for men; 310 milligrams for women
  • Adults 31 years and older: 420 milligrams for men; 320 milligrams for women
  • Pregnant women: 350–360 milligrams
  • Women who are breastfeeding: 310–320 milligrams

How much magnesium per day is best in supplement form? This depends on the type of magnesium you take, the condition you’re attempting to treat, and if you’re deficient.

In some cases, high doses up to 800–1800 mg of magnesium daily for several months are given to help treat conditions like indigestion and irregular heartbeats, but this is done under supervision from a doctor.

Is it safe to take 500 milligram of magnesium a day? Most authorities state that doses less than 350 mg daily are safest for most adults; in other words, the “daily upper intake level” for magnesium is 350 mg for anyone over 8 years old.

Unless your doctor tells you otherwise, it’s best to take about 300–400 mg daily at most. For children, magnesium is safe when taken in doses of between 65 to 100 mg/day depending on age,  or up to 350 mg/day for children older than 8 years.


Top 9 Health Benefits of Magnesium

1. Helps Increase Energy

What does magnesium do to help fight fatigue? Magnesium is used to create “energy” in your body by activating adenosine triphosphate, also known as ATP. This means that without enough magnesium, you don’t have the energy you need and can suffer from fatigue more easily.

Inadequate magnesium intake also means you tire more quickly and need a higher level of oxygen during exercise. One study conducted by the ARS Community Nutrition Research Group found that when magnesium-deficient women exercised, they needed more oxygen to complete low-level activities and had a higher heart rate compared to when their magnesium levels were higher.

2. Calms Nerves and Anxiety

Magnesium is vital for GABA function, an inhibitory neurotransmitter that produces “happy hormones” like serotonin. Certain hormones regulated by magnesium are crucial for calming the brain and promoting relaxation, which is one reason why a magnesium deficiency can lead to sleeplessness or insomnia.

In a 2012 report published in the Journal of Neuropharmacology, when mice became magnesium-deficient, they displayed enhanced anxiety-related behaviors compared to mice given magnesium supplements. Magnesium deficiency caused an increase in the production of cortisol hormones in the brains of the mice, specifically by activating the paraventricular hypothalamic nucleus, a part of the brain that controls responses to stress and anxiety.

3. Treats Insomnia and Helps You Fall Asleep

What’s the connection between magnesium and sleep? Magnesium supplements can help quiet a racing mind and make it easier to get a good night’s sleep. Our circadian rhythms shift, especially as we age because of our decreased nutrient consumption and a lower nutrient absorption, which puts many of us at risk for insomnia.

When 46 patients were either given magnesium supplements or a placebo over an eight-week period in a double-blind, randomized trial, the group taking magnesium supplements experienced a significant increase in sleep time, an easier time falling asleep, higher concentrations of melatonin (the hormone responsible for inducing sleepiness) and lower levels of cortisol, which are associated with stress.

Researchers who published the 2012 study in the Journal of Research in Medical Science concluded that magnesium supplementation is low-risk and effective for lowering insomnia symptoms; improves sleep efficiency, sleep time and sleep onset; plus it aids in early morning awakening and lowers concentrations of cortisol.

Magnesium Benefits

4. Helps with Digestion by Relieving Constipation

Magnesium helps relax muscles within the digestive tract, including the intestinal wall, which controls your ability to go to the bathroom. Because magnesium helps neutralize stomach acid and moves stool through the intestines, taking magnesium supplements is a natural way to help you poop!

When researchers from the National Institute of Health and Nutrition in Tokyo studied the effects of magnesium in the diet of 3,800 women, low magnesium intakes were associated with significant increases in the prevalence of constipation.

Another study found that when elderly patients experiencing constipation took magnesium supplements, they were more efficient at reducing constipation than the use of bulk-laxatives.

Keep in mind, however, that if you experience a laxative effect when taking magnesium supplements, you may be taking too high of a dose. Taking the proper dose of magnesium should help you go to the bathroom easily on a normal schedule but shouldn’t cause discomfort or diarrhea.

5. Relieves Muscle Aches and Spasms

Magnesium has an important role in neuromuscular signals and muscle contractions. When you don’t acquire enough magnesium, your muscles can actually go into spasms and cramp. Magnesium helps muscles relax and contract and also enables you to move around.

Additionally, magnesium balances calcium within the body, which is important because overly high doses of calcium, usually from supplements, can cause problems associated with muscle control, including controlling the heart.

While calcium is often taken in high quantities, magnesium supplements usually are not taken by most adults. This can result in the potential for intense muscle pains, cramps, contractions and weakness.

6. Regulates Levels of Calcium, Potassium and Sodium

Together with other electrolytes, magnesium regulates diverse biochemical reactions in the body. Magnesium plays a role in the active transport of calcium and potassium ions across cell membranes. This makes magnesium vital to nerve impulse conductions, muscle contractions and normal heart rhythms.

Magnesium, working with calcium, also contributes to the structural development of bone and is required for the synthesis of DNA, RNA and the antioxidant glutathione.

7. Important for Heart Health

Magnesium is very important for heart health. The highest amount of magnesium within the whole body is in the heart, specifically within the heart’s left ventricle. Magnesium works with calcium to support proper blood pressure levels and prevent hypertension.

Without a proper balance of magnesium to other minerals like calcium, serious heart problems can develop. In fact, a scientific article published in 2018 points out, “Magnesium deficiency can lead to serious morbidity and mortality, and has been implicated in multiple cardiovascular diseases such as hypertension, cardiomyopathy, cardiac arrhythmia, atherosclerosis, dyslipidaemia and diabetes.”

8. Prevents Migraines

Could low magnesium levels be contributing to your migraine headaches? Because magnesium is involved in neurotransmitter function and blood circulation, it can help control pain due to migraines by releasing pain-reducing hormones and reducing vasoconstriction, or constriction of the blood vessels that raises blood pressure.

Several studies show that when sufferers of migraines supplement with magnesium, their migraine pain and symptoms improve.

9. Helps Prevent Osteoporosis

What is magnesium good for when it comes to bone health? Magnesium is needed for proper bone formation and influences the activities of osteoblasts and osteoclasts that build healthy bone density.

Magnesium also plays a role in balancing blood concentrations of vitamin D, which is a major regulator of bone homeostasis. A higher magnesium intake correlates with increased bone mineral density in both men and women, according to several studies.

Research also shows that women can help prevent or reverse osteoporosis by increasing their magnesium consumption and preventing problematically low magnesium levels.

Other Benefits of Magnesium Supplementation

In addition to those described above, other benefits include:

  • Improve insulin sensitivity and metabolic control in people with type 2 diabetes. Elevated blood sugar levels increase the loss of magnesium in the urine, which in turn lowers blood levels of magnesium. So it’s not surprising that people with diabetes are more likely than those without to be low in magnesium since they struggle with their blood sugar levels. In a randomized, double-blind, controlled study, subjects with type 2 diabetes and decreased serum magnesium “who received magnesium supplementation showed significant higher serum magnesium concentration and lower HOMA-IR index, fasting glucose levels, and HbA1c than control subjects.” This led researchers to conclude that “oral supplementation with MgCl2 solution restores serum magnesium levels, improving insulin sensitivity and metabolic control in type 2 diabetic patients with decreased serum magnesium levels.”
  • Helping to manage depression
  • Supporting treatment of asthma symptoms, including among those who don’t respond well to other treatments
  • Helping to treat pre-eclampsia and eclampsia. In this case magnesium is usually given by either intramuscular or intravenous routes.

Best Food Sources of Magnesium

What foods have magnesium? Magnesium is found in such foods as green leafy vegetables, avocados, bananas, melon, legumes, nuts, seeds and certain whole grains. A good rule of thumb is that if a food contains dietary fiber, it also probably provides magnesium.

Magnesium is also added to some cereal grains — although this isn’t the preferred source, since refining the grains removes important, naturally occurring nutrients from the grain’s germ and bran.

If you had to pick just one food to eat regularly, what food is highest in magnesium that you should focus on? That would be dark leafy greens like spinach, chard or kale, since these not only provide magnesium but also many other antioxidants, nutrients and fiber, too.

Here are the top 12 magnesium foods to include in your diet (percentages based on the RDA for adult women of 320 milligrams/day):

  1. Spinach: 1 cup cooked: 157 milligrams (49 percent)
  2. Swiss Chard: 1 cup cooked: 150 milligrams (47 percent)
  3. Black Beans: 1 cup cooked: 120 milligrams (37 percent)
  4. Mung Beans: 1 cup cooked: 97 milligrams (30 percent)
  5. Almonds: ¼ cup: 97 milligrams (30 percent)
  6. Cashews: ¼ cup: 91 milligrams (28 percent)
  7. Potatoes: 1 large: 85 milligrams (26 percent)
  8. Pumpkin Seeds: 1/4 cup: 42 milligrams (13 percent)
  9. Avocado: 1 raw: 39 milligrams (12 percent)
  10. Bananas: 1 banana: 37 milligrams (11 percent)
  11. Broccoli: 1 cup cooked: 32 milligrams (10 percent)
  12. Brussel Sprouts: 1 cup cooked: 32 milligrams (10 percent)
Magnesium Rich Foods

Magnesium-Rich Recipes

Try the following recipes that are loaded with beneficial magnesium:


Potential Magnesium Supplement Side Effects and Precautions

How much magnesium is too much? Too much magnesium from food sources alone doesn’t pose a risk because any excess magnesium that the body doesn’t need is easily flushed out in the urine. It’s possible, however, to ingest too much magnesium from magnesium supplements, although magnesium overdose or toxicity is very rare and not thought to be a threat to most people.

Magnesium supplements that include magnesium carbonate, chloride, gluconate and oxide can cause digestive issues. One side effect of too much magnesium supplements is the laxative effect that it potentially causes, such as diarrhea and sometimes nausea and abdominal cramping. Usually this happens when someone goes over a 600 milligrams dose of magnesium, causing magnesium to produce osmotic activity in the intestines and colon, which can overstimulate the bowels.

To prevent a laxative effect, stick to the proper dose of magnesium and aim to have no more than 300–400 milligrams at one dose. Consuming high doses may result in side effects like: GI upset, irregular heartbeat, low blood pressure, confusion, slowed breathing, coma, and very rarely even death.

Consuming any supplement in doses that are too high can create an imbalance in other nutrients and toxicity. This is why it’s best to get magnesium or other nutrients from food sources, as foods naturally contain other important balancing nutrients. In the case of deficiency, a person may need to take a higher magnesium dosage for a certain period of time.

However, if possible, try to use food-based supplements in these cases, or be aware of how nutrients — such as calcium and magnesium — work together and how certain dosages and intakes can interact with one another.


Final Thoughts on Magnesium Supplements

  • Magnesium deficiency is one of the most common nutrient deficiencies in the world, and while I recommend getting as much as you can from magnesium-rich food sources, magnesium supplements can help some people.
  • Coming from the root word magnes, magnesium is one of the most crucial minerals for the body. It’s involved in over 300 biochemical functions in the body.
  • Some of the most common magnesium supplements include magnesium chelate, citrate, chloride oil, glycinate, threonate and orotate. You can take magnesium supplements orally or even get intravenous magnesium. It’s much more common to find and use oral magnesium supplements vs. intravenous supplements.
  • There are few risks associated with magnesium supplementation, but if you experience a laxative effect or symptoms like diarrhea, nausea or cramping, you may be taking too much magnesium.

Read Next: Calcium Deficiency: Are Supplements the Answer?


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