Magnesium deficiency (medicine)

This article is about magnesium deficiency in humans and animals. For the condition of low blood magnesium levels, see Hypomagnesemia. For the condition of poor magnesium nutrition in plants, see Magnesium deficiency (agriculture).

Magnesium deficiency
Classification and external resources
Magnesium
ICD-10	E61.2
MedlinePlus	002423

Magnesium deficiency refers to an intake of dietary magnesium below minimal levels, which can result in numerous symptoms and diseases. These can generally be remedied by an increase of magnesium in diet or oral supplements. However intravenous supplementation is necessary for more severe cases.

Symptoms

Symptoms of magnesium deficiency include: hyperexcitability, dizzyness, muscle weakness and fatigue.^[1] Severe magnesium deficiency can cause hypocalcemia, low serum potassium levels (hypokalemia), retention of sodium, low circulating levels of parathyroid hormone (PTH), neurological and muscular symptoms (tremor, muscle spasms, tetany), loss of appetite, nausea, vomiting, personality changes ^[2] and death from heart failure.^[3] Magnesium plays an important role in carbohydrate metabolism and its deficiency may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance.^[4] Deficiency can cause irregular heart beat.

Incidence/prevalence

61% of the US population does not meet the US RDA for levels of magnesium.^[5] The kidneys are very efficient at maintaining body levels, but not in cases where the diet is deficient.^{[citation needed]}

Terminology

"Magnesium depletion" (ICD10 code E83.4) should be distinguished from hypomagnesemia, since the first refers to a disorder of magnesium metabolism, and is much more difficult to treat. However, in the past, the terms have sometimes been used interchangeably. Magnesium deficiency can be present without hypomagnesemia, and hypomagnesemia can be present without magnesium deficiency.

Causes of magnesium deficiency include alcohol abuse, poorly controlled diabetes, excessive or chronic vomiting and/or diarrhea. Certain drugs can also deplete magnesium levels such as osmotic diuretics, cisplatin, ciclosporin, amphetamines, and possibly proton pump inhibitors. Also deficiency may occur in Bartter syndrome and Gitelman syndrome.

For a more detailed discussion on the subject of magnesium metabolism and causes of magnesium deficiency see hypomagnesemia.

Treatments

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 or tablet.

Magnesium aspartate, chloride, lactate, citrate and glycinate each have bioavailability 4 times greater than the oxide form and are equivalent to each other per amount of magnesium, though not in price.^[6][7]

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) are soluble in water, but are commonly used as a purgative, due to the poor absorption of the sulfate component. In lower doses, they may be used as an oral magnesium source, however.

Severe hypomagnesemia is often treated medically with intravenous or intramuscular magnesium sulfate solution, which is completely bioavailable, and effective.

See also

• Magnesium in biology
• Hypomagnesemia
• Hypermagnesemia

References

1. ^ http://www.nlm.nih.gov/medlineplus/ency/article/002423.htm
2. ^ Rude RK, Shils ME. Magnesium. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore: Lippincott Williams & Wilkins; 2006:223-247
3. ^ Health and Nutrition Secrets, Russell L. Blaylock, M.D., Health Press, 2006, page 395, ISBN 978-0-929173-48-1
4. ^ Kobrin SM and Goldfarb S. Magnesium Deficiency. Semin Nephrol 1990;10:525-35.
5. ^ "Community Nutrition Products and Services, Community Nutrition : CNMap". http://www.ars.usda.gov/Services/docs.htm?docid=10709. Retrieved 2007-07-24. 
6. ^ Firoz M, Graber M: "Bioavailability of US commercial magnesium preparations.", Magnesium Research 2001 Dec;14(4):257-62.
7. ^ Lindberg JS, Zobitz MM, Poindexter JR, Pak CY: "Magnesium bioavailability from magnesium citrate and magnesium oxide.",J Am Coll Nutr. 1990 Feb;9(1):48-55.