Definition
Magnesium oxide is a white, crystalline form of magnesium with the chemical formula MgO. It is a compound of magnesium and oxygen, commonly used in industry, medicine, and as a dietary supplement.
Chemical Composition
Magnesium oxide consists of magnesium ions (Mg2+) and oxide ions (O2-). Its chemical structure makes it an alkaline and stable compound with a high melting point but very low bioavailability. It is not a form of magnesium used in high-quality dietary supplements.
Properties
- High melting point: 2852°C
- Thermal conductivity and electrical insulation
- Soluble in acids but insoluble in water
- Alkaline nature
Applications
Magnesium oxide is used in a variety of applications, including:
- Industrial production: Ceramics, glass, and refractory materials
- Medical: Antacids and laxatives
- Dietary supplements to address magnesium deficiency. However, we do not recommend magnesium oxide due to its very low absorption rate and potential to irritate the intestinal lining.
How Is Magnesium Oxide Produced?
Raw Materials
The primary raw materials for producing magnesium oxide are magnesium-rich minerals such as magnesite (MgCO3) and dolomite (CaMg(CO3)2).
Production Processes
Magnesium oxide can be produced by heating magnesite or dolomite, which releases carbon dioxide and leaves behind magnesium oxide.
Calcination
Calcination is a process where the raw material is heated to high temperatures, typically between 600°C and 1200°C, to remove carbon dioxide and produce magnesium oxide.
Industrial Methods
In addition to calcination, the electrolysis of magnesium salt solutions is also used to produce magnesium oxide on an industrial scale.
How Is Magnesium Oxide Used as a Dietary Supplement?
Magnesium oxide is often used as a dietary supplement to increase magnesium intake, particularly for individuals with magnesium deficiency. However, magnesium oxide has very low bioavailability and should not be used to address magnesium deficiency.
What Are the Health Benefits and Risks of Magnesium Oxide?
Supplementation and Dosage
The recommended daily intake of magnesium varies depending on age and gender. For adults, the typical dosage is between 300–400 mg per day.
Health Benefits
Note that high-quality magnesium provides these health benefits, but the low bioavailability of magnesium oxide means it will not result in noticeable improvements.
- Supports normal muscle function
- Contributes to energy production
- Promotes healthy bone structure
- May reduce the frequency of migraines
Magnesium Deficiency
A deficiency in magnesium can lead to symptoms such as muscle cramps and fatigue.
Side Effects and Overdose
Excessive consumption of magnesium oxide may cause side effects such as diarrhea, nausea, and stomach discomfort. It is important not to exceed the recommended dosage.
Comparison with Other Magnesium Compounds
None of the magnesium forms listed below are recommended.
Magnesium Hydroxide
Magnesium hydroxide is primarily used as an antacid and laxative. It is less soluble in water than magnesium oxide and has a stronger alkaline effect.
Magnesium Carbonate
Magnesium carbonate is a common supplement used to increase magnesium intake and also functions as an antacid. It is less concentrated than magnesium oxide.
Magnesium Sulfate
Magnesium sulfate, also known as Epsom salt, is used both as a laxative and for muscle relaxation. It absorbs faster than magnesium oxide but has a shorter duration of effect.
Applications and Properties
Each magnesium compound has its unique properties and applications. Magnesium oxide is primarily used in low-quality dietary supplements.
Magnesium Oxide Is Not a Recommended Form of Magnesium
Note that magnesium oxide is not a form of magnesium we recommend due to:
- Low bioavailability: Magnesium oxide has poor absorption, meaning much of the magnesium ingested in this form may not be absorbed by the body, limiting its health benefits.
- Impact on the gastrointestinal tract: Due to its high osmotic strength, magnesium oxide can cause gastrointestinal discomfort, such as diarrhea and nausea, particularly at higher doses. This can make it uncomfortable for many people to use as a supplement.
- Less effective for specific health conditions: For individuals with magnesium deficiency or specific health needs, other forms of magnesium, such as magnesium citrate or magnesium glycinate, are more effective as they are easier to absorb and often provide more health benefits.
Magnesium M4, which is our best magnesium supplement, contains four types of magnesium: glycinate, malate, citrate, and taurate. It is a very pure product, completely free from magnesium oxide, even as a hidden ingredient. Learn more about magnesium.
