This article is about the medical use of magnesium. For the medical use of magnesium sulfate, see Magnesium sulfate (medical use). For more general information on magnesium as an element, see Magnesium.
Usually in lower dosages, magnesium is commonly included in dietary mineral preparations, including many multivitamin preparations. Chelated magnesium is sometimes used to aid in absorption.
In 2021, it was the 313th most commonly prescribed medication in the United States, with more than 300,000 prescriptions[1][2] and magnesium salts were the 211th most commonly prescribed medication, with more than 2million prescriptions.[1][3]
Overdose of magnesium (hypermagnesemia) is possible only in special circumstances. It can cause diarrhea,[8] nausea, vomiting, severely lowered blood pressure, confusion, slowed heart rate, respiratory paralysis.[7] In very severe cases, it can cause coma, cardiac arrhythmia, cardiac arrest and death.[7]
Magnesium is absorbed orally at about 30% bioavailability from any water soluble salt, such as magnesium chloride or magnesium citrate. The citrate is the least expensive soluble (high bioavailability) oral magnesium salt available in supplements, with 100 mg and 200 mg magnesium typically contained per capsule, tablet or 50 mg/mL in solution.[26]
The ligand of choice for large-scale manufacturers of multivitamins and minerals containing magnesium is the magnesium oxide due to its compactness, high magnesium content by weight, low cost, and ease-of-use in manufacturing. However it is insoluble in water. Insoluble magnesium salts such as magnesium oxide or magnesium hydroxide (milk of magnesia) depend on stomach acid for neutralization before they can be absorbed, and thus are relatively poor oral magnesium sources, on average.
Magnesium sulfate (Epsom salts) is soluble in water. It is commonly used as a laxative, owing to the poor absorption of the sulfate component. In lower doses, they may be used as an oral magnesium source, however.
Intravenous or intramuscular magnesium is generally in the form of magnesium sulfate solution. Intravenous or intramuscular magnesium is completely bioavailable, and effective. It is used in severe hypomagnesemia and eclampsia.
^Omu AE, Al-Harmi J, Vedi HL, Mlechkova L, Sayed AF, Al-Ragum NS (2008). "Magnesium sulphate therapy in women with pre-eclampsia and eclampsia in Kuwait". Medical Principles and Practice. 17 (3): 227–232. doi:10.1159/000117797. PMID18408392.
^Firoz M, Graber M (December 2001). "Bioavailability of US commercial magnesium preparations". Magnesium Research. 14 (4): 257–62. PMID11794633.
^Lindberg JS, Zobitz MM, Poindexter JR, Pak CY (February 1990). "Magnesium bioavailability from magnesium citrate and magnesium oxide". Journal of the American College of Nutrition. 9 (1): 48–55. doi:10.1080/07315724.1990.10720349. PMID2407766.