Magnesium is found in foods like nuts and legumes yet about half of the American population doesn't get the recommended amount in their diet — and up to one-third may have a magnesium deficiency, a 2016 report in [Nutrition Today](https://journals.lww.com/nutritiontodayonline/Abstract/2016/05000/Magnesium_Deficiency__What_Is_Our_Status.4.aspx)_ shows. If you've added more magnesium-rich foods to your meals and are still low in the mineral, you may benefit from talking to your doctor about taking a supplement.
Chelated magnesium is a type of magnesium supplement that can increase your intake of this essential mineral. All magnesium supplements contain magnesium itself (elemental magnesium) plus another atom or molecule that functions as a conjoined carrier for the mineral. The term chelated refers to how the elemental magnesium chemically binds to the carrier, which may influence the absorption of the mineral from the intestines into the bloodstream.
What's The Difference Between Chelated and Nonchelated Magnesium?
Magnesium is a highly reactive mineral, which means it most commonly exists in combination with another atom or molecule. In other words, magnesium hates to exist alone! Chelated magnesium refers to a supplement that contains elemental magnesium bound to a carrier by two or more points of attachment. In contrast, nonchelated magnesium supplements contain magnesium bound to a carrier by a single point of attachment.
This difference might seem like minutia at first blush, but it's vital when you're trying to navigate the broad array of available magnesium offerings in the supplement aisle. Understanding how magnesium supplements differ can help you make the best choice for your health — and your wallet!
Forms of Chelated Magnesium
Now that you understand the difference between chelated and nonchelated magnesium supplements, it's time to get specific. Over-the-counter forms of chelated magnesium include:
- Magnesium ascorbate
- Magnesium carbonate
- Magnesium citrate
- Magnesium fumarate
- Magnesium gluconate
- Magnesium lactate
- Magnesium malate
- Magnesium orotate
- Magnesium aspartate*
- Magnesium glycinate* (also known as magnesium bisglycinate or diglycinate)
- Magnesium taurate* (also known as magnesium ditaurate)
- Magnesium threonate* (also known as magnesium L-threonate)
The forms of chelated magnesium listed with an asterisk (*) are amino acid chelates, meaning that the carrier molecule is an amino acid. Amino acids are the building blocks your body uses to make the proteins it needs — everything from the enzymes that help you digest food to the muscle tissue that powers your workouts.
Some people use the term chelated magnesium to refer exclusively to amino acid magnesium chelates — but this is incorrect. As noted in the list, there are several forms of chelated magnesium that do not employ an amino acid carrier.
To help you navigate the various magnesium supplements out there, it's important to know which forms of over-the-counter magnesium are not chelated. These include magnesium chloride and magnesium oxide.
How to Get the Most Out of Your Magnesium Supplement
If you're taking a magnesium supplement, you obviously want most of the mineral to be absorbed. The percentage of a given dose of magnesium that the intestines absorb and deliver to the bloodstream is referred to as its bioavailability.
Intestinal magnesium absorption is generally rather low. Only 30 to 50 percent magnesium from the diet is typically absorbed daily, according to a January 2015 study published in Physiological Reviews. The bioavailability of magnesium supplements is generally similarly limited.
Many factors influence the bioavailability of both dietary and supplemental magnesium, as reviewed in a November 2017 Current Nutrition and Food Science article. Some of these factors include:
- Magnesium status: A low blood magnesium level tends to boost intestinal absorption of the mineral.
- Magnesium dose: High doses of magnesium typically result in a lower overall percent of absorption.
- Supplemental magnesium form: Chelated magnesium seems to exhibit slightly higher bioavailability compared to nonchelated magnesium supplements, based on limited research data.
- Intestinal ailments (such as Inflammatory Bowel Disease [IBD] and celiac disease): People suffering from intestinal diseases often exhibit impaired absorption of many nutrients and micronutrients.
- Co-ingested foods: Certain foods enhance intestinal magnesium absorption while others inhibit it.
- Co-ingested minerals: Taking a supplement that contains calcium, copper, iron, manganese, phosphorus and/or zinc along with a magnesium supplement tends to reduce magnesium absorption.
- Age: Older people typically have less effective overall intestinal absorption compared to younger people.
While the authors of the November 2017 study state that most research to date shows that chelated magnesium's bioavailability is slightly better than nonchelated supplements, research is lacking to determine whether some magnesium chelates might be better absorbed than others.
You might read assertions claiming that amino acid magnesium chelates exhibit higher bioavailability than other forms of chelated magnesium but this has not been conclusively proven in human studies. Additional research is needed to determine whether some forms of chelated magnesium are superior to others.
Uses and Possible Benefits
A magnesium deficiency, or hypomagnesemia, is a leading reason people begin taking chelated magnesium. Risk factors for hypomagnesemia include diabetes, IBD, celiac disease, surgical removal of part of the bowel, abdominal radiation therapy, alcoholism, advanced age and long-term use of certain types of water pills (diuretics).
Your healthcare provider might recommend magnesium supplementation as part of the treatment plan for certain conditions, such as high blood pressure, migraines, osteoporosis, prediabetes and diabetes. Researchers are also studying the possible role of magnesium supplementation in managing depression.
Potential Side Effects and Other Considerations
The most frequent side effect people report from taking magnesium supplements is diarrhea, sometimes accompanied by abdominal cramps and/or nausea. This digestive system upset most commonly occurs with magnesium carbonate, chloride, gluconate and oxide, reports the National Institutes of Health Office of Dietary Supplements.
The price of the various forms of chelated magnesium varies considerably. If cost is a consideration for you, be aware that amino acid chelates tend to cost more than other forms of chelated magnesium. Some products contain a mixture of different forms of chelated magnesium, often in combination with vitamins or other micronutrients.
Speak with your doctor about any health conditions you have and any medications or supplements you take before starting a magnesium supplement to be sure it is safe for you. This is particularly important if you have kidney disease or are pregnant or breastfeeding. Your healthcare provider will advise you about the recommended dosage based on your individual circumstances.
- Nutrition Today: "Magnesium Deficiency: What Is Our Status?"
- Current Nutrition and Food Science: "Intestinal Absorption and Factors Influencing Bioavailability of Magnesium - An Update"
- Physiological Reviews: "Magnesium in Man: Implications for Health and Disease"
- National Institutes of Health Office of Dietary Supplements: "Magnesium"