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What is Magnesium Oxide?

Angie Bates
Angie Bates

Magnesium oxide is a type of dietary supplement most commonly prescribed by doctors for low magnesium levels in the body. Magnesium oxide may also be used as an antacid or as a strong laxative right before surgery. Although it is available without a prescription, a doctor should be consulted before taking this supplement.

Magnesium is important to the body as it helps maintain the health of muscles and nerves. Low magnesium levels may simply be caused by a poor diet, but alcoholism and many diuretics will also deprive the body of magnesium. Eating foods high in magnesium, such as green vegetables, avocados, bananas, and nuts, is a good way to boost magnesium levels in the body without taking supplements.

Avocados are a good source of magnesium.
Avocados are a good source of magnesium.

Magnesium oxide most often comes in tablet or capsule form, but can be occasionally found in liquid form as well. It should be taken with a glass of water and never on an empty stomach. Capsules should not be broken up, chewed, or crushed, but instead swallowed whole. If a dose is missed, a double dose should never be taken. This supplement should be stored at room temperature and out of moisture.

Magnesium oxide is sometimes used as an antacid.
Magnesium oxide is sometimes used as an antacid.

A person who has kidney disease, certain allergies, or is pregnant typically should not take this supplement. When used as a laxative, magnesium oxide generally should not be taken for longer than one week. When used as an antacid, it should be taken no longer than two weeks.

Magnesium oxide can inhibit the full effect of certain medications, such as tetracycline, when the medications are taken together. To prevent this, magnesium oxide should be taken two to three hours before or after taking other medications. This supplement also should not be taken with certain antacids because the interaction between the drugs can cause serious side effects.

When a person has a magnesium deficiency, she may exhibit symptoms such as muscle weakness and fatigue.
When a person has a magnesium deficiency, she may exhibit symptoms such as muscle weakness and fatigue.

Side effects of magnesium oxide include itching, possibly with a rash or hives, fatigue, both physical and mental, dizziness and nausea, and mood swings. Side effects range from mild to serious, though most people taking the supplement do not develop, or are not bothered by, side effects. If a person does develop side effects, he or she should consult a medical professional.

Spinach is particularly high in magnesium, a mineral that is required for a well-functioning nervous system.
Spinach is particularly high in magnesium, a mineral that is required for a well-functioning nervous system.

It is possible to overdose on magnesium oxide. Overdosing causes the heart to slow and blood pressure to lower. The person may feel drowsy or nauseous to the point of vomiting. Medical attention should be sought immediately if an overdose is suspected.

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    • Avocados are a good source of magnesium.
      By: Richard Villalon
      Avocados are a good source of magnesium.
    • Magnesium oxide is sometimes used as an antacid.
      By: Photographee.eu
      Magnesium oxide is sometimes used as an antacid.
    • When a person has a magnesium deficiency, she may exhibit symptoms such as muscle weakness and fatigue.
      By: concept w
      When a person has a magnesium deficiency, she may exhibit symptoms such as muscle weakness and fatigue.
    • Spinach is particularly high in magnesium, a mineral that is required for a well-functioning nervous system.
      By: travelbook
      Spinach is particularly high in magnesium, a mineral that is required for a well-functioning nervous system.
    • Nuts are typically a good source of magnesium.
      By: JJAVA
      Nuts are typically a good source of magnesium.
    • Eating bananas can help boost magnesium levels without taking supplements.
      By: jayfish
      Eating bananas can help boost magnesium levels without taking supplements.