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Magnesium is one of the essential minerals a body requires. A daily intake of magnesium is required to maintain healthy levels. In a government report almost half (48%) of the US population consumed less than the required amount of magnesium from food. Magnesium has been used to treat symptoms of Periodic limb Movements and Restless legs Syndrome.


Table 1: Recommended Dietary Allowances (RDAs) for Magnesium

Male: Age 19-30 400mg, Age 31 plus 420mg.

Female: Age 19-30 310mg, Age 31 plus 320mg


Symptomatic magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon.

Magnesium inadequacy can occur when intakes fall below the RDA but are above the amount required to prevent overt deficiency. This is 48% of the USA population. Those most at risk are:

  • People with gastrointestinal diseases
  • People with type 2 diabetes
  • People with alcohol dependence
  • Older adults

Low intake of magnesium over time can lead to:

  • Hypertension and cardiovascular disease
  • Type 2 diabetes
  • Osteoporosis
  • Migraine headaches


Too much magnesium from food does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine.

However, high doses of magnesium from dietary supplements or medications often result in diarrhea that can be accompanied by nausea and abdominal cramping. Forms of magnesium most commonly reported to cause diarrhea include magnesium carbonate, chloride, gluconate, and oxide. The diarrhea and laxative effects of magnesium salts are due to the osmotic activity of unabsorbed salts in the intestine and colon and the stimulation of gastric motility.

Very large doses of magnesium-containing laxatives and antacids (typically providing more than 5,000 mg/day magnesium) have been associated with magnesium toxicity. Symptoms of magnesium toxicity, which usually develop after serum concentrations exceed 1.74–2.61 mmol/L, can include hypotension, nausea, vomiting, facial flushing, retention of urine, ileus, depression, and lethargy before progressing to muscle weakness, difficulty breathing, extreme hypotension, irregular heartbeat, and cardiac arrest. The risk of magnesium toxicity increases with impaired renal function or kidney failure because the ability to remove excess magnesium is reduced or lost.


  • Milk
  • Oatmeal
  • Bran Flakes
  • Beets
  • Corn
  • Peas
  • Bananas
  • Pineapple
  • Nuts and Seeds especially Almonds and sunflower seeds.


The USA Food and Nutrition Board has established the tolerable upper intake level for Supplemental Magnesium for adults as 350mg per day. Checking with both your Pharmacist and Primary Physician prior to starting any supplement is strongly recommended.

Magnesium supplements are available in a variety of forms, including magnesium oxide, citrate, and chloride.

Absorption of magnesium from different kinds of magnesium supplements varies. Forms of magnesium that dissolve well in liquid are more completely absorbed in the gut than less soluble forms. Small studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed more completely and is more bioavailable than magnesium oxide and magnesium sulfate.

External links

[[1]] Suboptimal magnesium status report [[2]]Magnesium Rich Foods [3] Magnesium Therpy for PLMS/RLS [4]Magnesium Fact Sheet