Magnesium is an essential mineral to the human body. It is needed for bone, protein, and
fatty acid formation, making new cells, activating B vitamins, relaxing muscles, clotting blood, and
forming adenosine triphosphate (ATP; the energy the body runs on). The secretion and action of
insulin also require magnesium.
Reliable
and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
benefit.
Who is likely to be deficient?
Magnesium deficiency is common in people taking “potassium-depleting” prescription diuretics. Taking too many laxatives can also lead to
deficiency. Alcoholism, severe burns,
diabetes, and heart failure are other
potential causes of deficiency. In a study of urban African-American people (predominantly
female), the overall prevalence of magnesium deficiency was 20%. People with a history of
alcoholism were six times more likely to have magnesium deficiency than were people without
such a history.1 The low magnesium status seen in alcoholics with liver cirrhosis contributes to the development of hypertension in these people.2
Almost two-thirds of people in intensive care hospital units have been found to be
magnesium deficient.3 Deficiency may also occur in people with chronic diarrhea, pancreatitis, and other conditions
associated with malabsorption.
Fatigue, abnormal heart rhythms, muscle
weakness and spasm, depression, loss of
appetite, listlessness, and potassium
depletion can all result from a magnesium deficiency. People with these symptoms should be
evaluated by a doctor before taking magnesium supplements.
As previously mentioned, magnesium levels have been found to be low in people with chronic fatigue syndrome.
Deficiencies of magnesium that are serious enough to cause symptoms should be treated by
medical doctors, as they might require intravenous administration of
magnesium.4
How much is usually taken?
Most people don’t consume enough magnesium in their diets. Many nutritionally
oriented doctors recommend 250–350 mg per day of supplemental magnesium for adults.
Are there any side effects or interactions?
Comments in this section are limited to effects from taking oral magnesium. Side effects
from intravenous use of magnesium are not discussed.
Taking too much magnesium often leads to
diarrhea. For some people this can happen with amounts as low as 350–500 mg per day.
More serious problems can develop with excessive magnesium intake from magnesium-containing
laxatives. However, the amounts of magnesium found in nutritional supplements are unlikely to
cause such problems. People with kidney disease should not take magnesium supplements without
consulting a doctor.
Vitamin B6 increases the amount of
magnesium that can enter cells. As a result, these two nutrients are often taken together.
Magnesium may compete for absorption with other minerals, particularly calcium. Taking a multimineral supplement avoids this potential
problem.
Are there any drug
interactions?
Certain medicines may interact with magnesium. Refer to drug interactions for a list of those medicines.
References
1. Fox CH, Ramsoomair D, Mahoney MC, et al. An investigation of
hypomagnesemia among ambulatory urban African Americans. J Fam Pract
1999;48:636–9.
2. Kisters K, Schodjaian K, Tokmak F, et al. Effect of ethanol on blood
pressure—role of magnesium. Am J Hypertens 2000;13:455–6 [letter].
3. Weisinger JR, Bellorin-font E. Magnesium and
phosphorus.Lancet 1998;352:391–6 [review].
4. Weisinger JR, Bellorin-font E. Magnesium and
phosphorus.Lancet 1998;352:391–6 [review].
The information presented in Aisle7 is for informational purposes only.
It is based on scientific studies (human, animal, or in vitro), clinical experience,
or traditional usage as cited in each article. The results reported may not necessarily occur
in all individuals. For many of the conditions discussed, treatment with prescription or over
the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist
for any health problem and before using any supplements or before making any changes in
prescribed medications.
The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical expericence, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires January 2010.
HealthNotes
