Magnesium Citrate, Oxide, and Glycinate: Benefits, Dosage and More (Science Based)

Magnesium is an essential mineral that is necessary for your body to function properly. Magnesium supplements are sometimes necessary to address the symptoms of a magnesium deficiency.

Magnesium citrate, magnesium oxide, and magnesium glycinate can help to improve nerve function, energy metabolism, and relieve constipation.

If you show symptoms of a magnesium deficiency, it can be difficult to choose the best magnesium supplement to take. Magnesium oxide, citrate, and glycinate all contain enough available magnesium to prevent magnesium deficiencies.

In this article, I will examine what scientific research reveals as to the benefit of magnesium oxide, citrate, and glycinate supplements. This will help you decide on the best magnesium supplement for you.

Why is Magnesium Important?

Magnesium is important because it directly affects energy production, DNA synthesis, nerve impulses, muscle contractions, and heart rhythm.

Researchers from the National Institutes of Health report that magnesium is responsible for over 300 chemical reactions in the body. These chemical reactions influence blood pressure, blood glucose levels, nerve function, and muscle function.¹

Your body only contains about 25 grams of magnesium. Half of your body’s magnesium levels are stored in the bones and the other half in soft tissues. A tiny amount magnesium is stored in blood serum.

Dr. Bishnu Prasad Devkota on Medscape says that the normal range for magnesium (Mg) level in blood is 0.7-1 mmol/L.²

What is Magnesium Oxide?

Magnesium oxide occurs naturally in nature and is used as a mild laxative to relieve constipation and reduce heartburn.

The National Center for Biotechnology Information says that magnesium oxide (MgO) is the oxide salt of magnesium. Magnesium oxide is commonly mixed with water and used as a muscle relaxant, reduce the acidity of stomach acid, and assist in alleviating constipation.³

A well-known form of magnesium oxide for constipation is Milk of magnesia. This preparation includes 500 mg elemental magnesium per tablespoon.

Research into the benefits of magnesium oxide has shown that its bioavailability is fairly poor. Bioavailability refers to the amount of magnesium in the supplement that the body can absorb. A 2001 study into the best type of inorganic magnesium salts found that magnesium oxide was poorly absorbed.⁴

One use for magnesium oxide is to improve bone mineral content in preadolescents. A study from 2006 found that regularly taking 300 mg magnesium oxide over a 12-month period can help to increase bone mineral content in girls between ages 8 and 14.⁵

Magnesium oxide is also used as an antacid for heartburn or laxative for treating constipation.

What is Magnesium Citrate?

Magnesium citrate is used to address symptoms of a magnesium deficiency. Some preparations containing Mg citrate increase fluid in the intestines and can assist in relieving the symptoms of constipation.

One of the benefits of taking magnesium citrate is that it is more readily absorbed when compared to other magnesium supplements. The journal Magnesium Research reported that 300 mg elemental magnesium in the form of magnesium citrate had better results than magnesium oxide or magnesium amino-acid chelate.⁶

Although magnesium citrate can be used as a natural laxative, it does have other uses in addressing magnesium deficiencies. For example, a small short-term trial showed that magnesium citrate can help prevent osteoporosis in postmenopausal women.⁷

Magnesium citrate tablets, pills, and supplements are the most popular type of treatment for magnesium deficiency.

Doctors on WebMD report that the possible side effects linked to magnesium citrate are gastrointestinal issues. You may feel abdominal cramping or have bouts of nausea or a buildup of excess gas.⁸

Some people say that you can use magnesium citrate to lose weight. Please read my article on what science really says about magnesium citrate and weight loss.

What is Magnesium Glycinate?

Magnesium glycinate is used to help offset symptoms of a magnesium deficiency and boost blood serum magnesium levels.

Supplementing your diet with magnesium glycinate may be necessary if you have low magnesium levels. Doctors from WebMD say that Mg glycinate is sometimes recommended if you have a poor diet, take diuretics, or have problems with nutrient absorption.⁹

Research into the benefits of magnesium glycinate shows that it can help with anxiety disorders. For example, the Nutrition Journal reported in 2008 that magnesium glycinate can help treat depression. Patients received 125 to 300 mg magnesium glycinate before eating and going to bed. In many cases, it took less than 7 days to recover from depression.¹⁰

Magnesium glycinate can also help strengthen bones. Clinical research found that a combination of magnesium glycinate, calcium, vitamin D, and zinc helped bones heal quicker after bone implants.¹¹

As with most magnesium supplements, the most common side effects can be diarrhea and stomach cramps.

Magnesium Oxide vs. Magnesium Citrate Supplement

The benefits of taking magnesium supplements are connected with the amount of elemental magnesium they contain. It is also important to know how much magnesium can be absorbed by the body (bioavailability).

Two popular supplements for magnesium deficiencies are magnesium oxide and magnesium citrate. How do the two compare?

Research published in the Journal of the American College of Nutrition compared the bioavailability of magnesium citrate and magnesium oxide. It found that magnesium citrate was more soluble in water and was better absorbed by the body than magnesium oxide.¹²

Even though magnesium oxide has more elemental magnesium when compared to other magnesium supplements, less is absorbed by the body. In fact, a comparison of many magnesium supplements found that only 4% of magnesium oxide is absorbed during digestion.¹³

Therefore, magnesium citrate is better than magnesium oxide in addressing issues connected to magnesium deficiency.

Magnesium Glycinate vs. Magnesium Citrate Supplement

How do magnesium citrate and magnesium glycinate compare when it comes to elemental magnesium and absorption?

When discussing magnesium supplementation when treating anxiety and stress, a systematic review published in 2017 found both magnesium glycinate and citrate have high absorption rates.¹⁰

When compared with magnesium oxide, magnesium glycinate was better absorbed. Researchers found that magnesium diglycinate (glycinate) is a highly available form of magnesium. When taken as a supplement, a portion of magnesium diglycinate (glycinate) is absorbed intact.¹⁴

However, according to research published in the Journal of the American College of Nutrition (quoted earlier), magnesium citrate is generally viewed as the most highly bioavailable form of magnesium supplement.¹²

Many people say that magnesium glycinate is better tolerated than magnesium citrate. So, if magnesium citrate is causing digestive problems, you could try lowering the dose or switching to magnesium glycinate.

Other Types of Magnesium

So far, I have looked at 3 of the most popular magnesium supplements – citrate, oxide, and glycinate. Here are 6 other magnesium supplements that can help to resolve a magnesium deficiency:

Magnesium orotate. Clinical evidence shows that magnesium orotate is well tolerated and an effective magnesium supplement. Research has found that magnesium orotate doesn’t have laxative effect and can boost depleted magnesium levels.¹⁵

Magnesium carbonate. This type of magnesium is often used in commercially-produced antacid preparations. Taken in large quantities, magnesium carbonate has a laxative effect.

Magnesium sulfate. Commonly called Epsom Salt, magnesium sulfate (food grade) is sometimes ingested to help relieve constipation and make bowel movements easier. Please read this article for more amazing ways to use Epsom Salt.

Magnesium chloride. Magnesium chloride has a high bioavailability and lower levels of elemental magnesium.¹⁶ Some people use magnesium chloride as magnesium oil that they rub on their skin. It is said that this helps to relax muscles and even resolves magnesium deficiencies without digestive upset. However, a comprehensive review published in 2017 didn’t find any evidence a topical application of magnesium oil works.¹⁷

Magnesium aspartate. This kind of magnesium supplement is connected to an amino acid and also called magnesium amino acid chelate. Evidence suggests that magnesium aspartate is absorbed well. Magnesium aspartate is also used for treating magnesium deficiencies.¹⁸

Signs of Magnesium Deficiency

A low level of magnesium in blood serum is called hypomagnesemia and can have a negative impact on your body and general health. Magnesium citrate, oxide, and glycinate are various magnesium compounds that help to treat signs of a magnesium deficiency.

The journal Clinical Endocrinology reports that it can be difficult to diagnose low levels of magnesium in the body. However, hypomagnesemia can be detected in a blood test and can be treated with intravenous magnesium treatment.¹⁹

Many people with lower than normal levels of magnesium may only show symptoms that could be mistaken for other conditions (asymptomatic). Professor of Medicine at Ralph H. Johnson VA Medical Center, Dr. Tibor Fulop, says that asymptomatic signs of a magnesium deficiency generally affect the cardiovascular system or central nervous system.²⁰

Signs that you may be deficient in magnesium can include:

• Muscle twitching or muscle cramps
• Muscle weakness
• High blood pressure
• Irregular heartbeat
• Depression and mood swings or increased irritability
• Osteoporosis due to low magnesium affecting calcium levels

Related: 14 Warning Signs of Low Magnesium Levels and What to Do About It

Risk factors for magnesium deficiencies

A diet lacking in essential minerals and vitamins can cause a magnesium deficiency in anyone. Researchers from the National Institutes of Health report that you may be at more risk of magnesium deficiency if you have the following conditions:¹

Gastrointestinal disease and magnesium deficiency. The journal Digestive Diseases reported that people with inflammatory bowel disorders are more likely to have magnesium deficiency as well as lacking other nutrients. This is due to issues regarding malabsorption.²¹

Type 2 diabetes. If you have type 2 diabetes then there is a greater possibility that you have magnesium deficiency.²²

Alcoholism. Apart from affecting the health of your liver, chronic overindulgence in alcohol can result a magnesium deficiency. Researchers have found that alcoholism depletes magnesium levels, causes excess urination, and can result in pancreatitis – all of which can contribute to deficiency in magnesium.²³

Taking certain medications. A report from 2017 found that proton pump inhibitors for reflux, antacids, antibiotics, some blood pressure drugs, and diuretics can all reduce magnesium levels.²⁴

How Much Magnesium Should You Take? Optimal Magnesium Dosage

Supplements like magnesium citrate can help to increase levels of magnesium and prevent symptoms of a magnesium deficiency. However, knowing just how much magnesium to take can be difficult to know.

Dr. Tibor Fulop (quoted earlier) says that only a tiny percentage in magnesium is detectable in blood serum. Most magnesium is stored in muscles and bones. Therefore, observing the effect of magnesium supplements on reducing the clinical symptoms of low magnesium levels can help to determine how much magnesium to take and for how long.²⁵

According to WebMD, in addition to what you get from food, the highest dose you should take of magnesium supplements is:²⁶

• Children ages 1-3: 65 mg/day
• Children ages 4-8: 110 mg/day
• Children over 9 and adults: 350 mg/day

How much magnesium do you need daily? The National Institutes of Health has provided the following information on RDA for magnesium:²⁷

• Infants: between 30 mg and 70 mg depending on their age
• Children ages 1-3: 80 mg
• Children ages 4-8: 130 mg
• Children ages 9-13: 240 mg
• Males aged 14 and over: 400 – 420 mg
• Females aged 14 and over: 310 – 320 mg
• Pregnant women: 350 – 400 mg

What is the Best Magnesium Supplement

In most cases, the best magnesium supplement to take to treat a deficiency in magnesium is magnesium citrate. As this article has shown, there is plenty of scientific evidence to support the fact that magnesium citrate has good bioavailability and is easily absorbed by the body.

Other magnesium supplements that have shown to be well tolerated and deliver good results are magnesium chloride, magnesium lactate, magnesium aspartate, and magnesium glycinate.⁴

Should You Take a Magnesium Supplement?

In most cases, you shouldn’t have to take a magnesium supplement if you enjoy a healthy diet with plenty of green vegetables and fruits. Before thinking about taking a magnesium supplement, you should increase magnesium through your diet.

The best foods to include in your diet to prevent a magnesium deficiency and avoid taking magnesium supplements are:

• Green leafy vegetables
• Whole grain foods
• Nuts and seeds
• Dairy products
• Foods fortified with vitamins and minerals

Because it can be difficult to know if you are getting adequate amounts of magnesium in your diet, some people decide to take a magnesium supplement as a preventative measure. If you decide to do so, it’s important to follow the manufacturer’s instructions on the optimal dosage.

Other Benefits of Magnesium Supplements

If you have signs of a magnesium deficiency or you suspect that your magnesium levels are lower than normal, you may benefit from a magnesium supplement.

According to a review published in the journal Nutrients, some of the benefits of taking magnesium supplements that are backed up by science are as follows:²⁸

• Magnesium supplementation can help lower anxiety and stress²⁹
• Improve sleep patterns and help treat insomnia³⁰
• Reduce discomfort from muscle cramps and aches and general muscle pain
• Lessen the frequency and intensity of cluster headaches, migraine, and headaches associated with menstruation
• Help keep a regular heartbeat and protect against cardiovascular disease
• Magnesium supplements can regulate blood pressure if you have an Mg deficiency

Related articles:

• 14 Warning Signs of Low Magnesium Levels and What to Do About It
• 5 Essential Nutrients You May Be Missing From Your Diet
• Top Signs of Iron Deficiency and How To Increase Iron Levels In Your Blood