Daily magnesium oxide supplements can help prevent or treat low magnesium in the blood, according to WebMD. While a balanced diet provides the necessary amount of magnesium, poor diet, alcoholism, stomach problems and diabetes can cause the body to expel more magnesium than usual.
Magnesium oxide can cause stomach upset and diarrhea, reports WebMD. However, these side effects can usually be minimized or neutralized by taking magnesium oxide with a meal. While rare, magnesium oxide can trigger a severe allergic reaction with symptoms including a rash, itching and dizziness.
Low magnesium levels, known as hypomagnesemia, can be caused by large burns, diarrhea, malnutrition, malabsorption problems and certain medications, according to MedlinePlus. Even excessive sweating can lead to magnesium deficiencies. Symptoms of hypomagnesemia are abnormal eye movements, convulsions, fatigue, muscle cramps or weakness, and numbness.
Magnesium is critical for normal functioning of the heart, cells, nerves, muscles and bones, reports WebMD. Hypomagnesemia can lead to cardiac or respiratory arrest and even death, warns MedlinePlus. Intake recommendations vary based on age and gender, but the National Institutes of Health recommend that adult men get 400 to 420 milligrams each day. Adult women need 310 to 320 milligrams, but require more during pregnancy and lactation. While magnesium oxide is a common supplement for magnesium, studies have discovered that it may be less readily absorbed than magnesium available in other forms.