Magnesium Supplements: Benefits, Types and Dosage - Dr. Axe

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Magnesium Supplements: Types, Benefits and How Much to Take


Magnesium supplements - 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 benefits include include 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. One study indicated that magnesium citrate and glycinate are better absorbed than magnesium oxide and sulfate, but more research is needed to determine the comparative bioavailability. Usually types that dissolve in liquid are better absorbed in the gut than less soluble forms.

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

1. Magnesium Glycinate

Highly absorbable, magnesium glycinate is recommended for anyone with a known magnesium deficiency and less likely to cause laxative effects than some other magnesium supplements.

2. Magnesium Citrate

This is 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.

3. Magnesium Chloride

An oil form of magnesium, magnesium chloride 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.

4. Magnesium Sulfate

A combination of magnesium, sulfur and oxygen that is sold as Epsom salt, magnesium sulfate is usually added to baths as it seeps through the skin, relieving sore muscles and promoting relaxation.

5. Magnesium Oxide

Typically used as a laxative and remedy for acid reflux, magnesium oxide may be taken in higher doses than other forms since its not absorbed as well. Another name for this type is hydroxide, which is the ingredient in milk of magnesia that is taken for heartburn symptoms.

6. Magnesium Malate

Magnesium malate is a dietary supplement that combines the essential mineral magnesium and malic acid, an organic compound that’s found in apples and other food sources. A 2018 study revealed fairly impressive bioavailability in rats for an extended time.

7. Magnesium Threonate

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.

8. Magnesium Chelate

Magnesium chelate is 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.

9. Magnesium Orotate

These supplements have orotic acid, and magnesium orotate is beneficial to the heart.


Dosage: How Much Magnesium to Take

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.

So, 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 Recommended Daily Allowances (RDA) for magnesium:

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

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.

Risks and Side Effects

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

  • 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.

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