encyclopedia

Magnesium

Natural Sources:
Whole grains, nuts, seeds, legumes, bran, pumpkin, squash and other foods are good sources of magnesium.

Forms:
Standardized magnesium capsules, tablets and liquid supplements; multivitamins containing magnesium.

Therapeutic Uses:
Aging Disorders
Alzheimer’s Disease
Antioxidant
Atherosclerosis
Blood Pressure Control
Bone Health
Brain and Mental Functioning
Breathing Disorders
Bronchitis
Bursitis
Cancer Prevention
Cardiac Arrhythmia
Cell Membrane Health
Cellular Regeneration
Chronic Fatigue Syndrome
Circulatory Health
Coordination
Dental Health
Depression
Dysmennorhoea
Eclampsia (Pregnancy-related high blood pressure)
Energy Loss
Fatigue
Gastrointestinal Disorders
Gingivitis
Growth Impairment
Hair Loss
Headache
Heart Health Maintenance
Heart Palpitations and Fluctuations
High Blood Pressure
High Cholesterol
Intermittent Claudication (reduced blood flow to the legs)
Lethargy
Mental Confusion
Mineral Deficiency (RDA=400mg/day)
Mood Swings and Disorders
Multiple Sclerosis
Muscle Spasms
Muscular Fatigue and Weakness
Nausea
Nervous System Health
Osteomalacia Prevention
Osteoporosis
PMS
Respiratory Disorders
Tendinitis
Vascular Disorders

Overview:

Magnesium (Mg) is a silvery white alkaline metal that burns in air with a beautiful (but blinding) white light. It takes its name from magnesite ore, named for the district Magnesia in Thessaly, Greece. It is the eighth most abundant element in the earth’s crust. Magnesium is an essential nutritional element in trace amounts and is the central atom of chlorophyll, the green photosynthetic compound that gives plants their color. Every cell of the human body needs magnesium for energy metabolism and protein synthesis. Magnesium catalyses more than 300 enzymatic reactions, in particular those involving the fundamental energy molecule of the body, ATP. It helps maintain normal muscle and nerve function, keeps heart rhythm steady and bones strong. Most people understand how important calcium is for the strength of bones and teeth and the health of skin, but few realize that magnesium is also essential. For adults, the recommended daily allowance for magnesium is about 500 milligrams. About half of the total magnesium in the body is found intra-cellularly in soft tissues, and the other half is combined with calcium and phosphorus in bone. Blood levels of magnesium represent only 1% of the body’s total magnesium store. The human body works very hard to keep blood levels of magnesium constant. Despite the importance of magnesium to myriad bodily functions, hypomagnesemia (magnesium deficiency) is surprisingly common in hospital populations and in the general public and often remains undetected and overlooked. Magnesium deficiency may result in a condition known as hypocalcaemia (low calcium). In heart tissue, magnesium depletion can lead to an influx of sodium and calcium cations into the mitochondria (where energy for a cell is produced) and this may lead to myocardial cell death. Researchers conclude that magnesium deficiency may be a factor in a large number of common diseases.

Chemistry:
Magnesium is a silver-white metal that reacts with hot water and acids. The metal is widely distributed in the environment in a number of minerals and a significant amount is found in seawater. It does not occur uncombined, but is found in large deposits in the form of magnesite, dolomite, and other minerals. Recognized as an element as far back as 1775, it was first isolated in pure form in 1805. Forms used in mineral supplements include Magnesium Chloride, Magnesium Asparate, Magnesium Glucoate, Magnesium Lactate, and Magnesium Oxide.

Suggested Amount:
The Recommended Daily Allowance for magnesium is 300mg daily. The typical supplemental dosage is between 200-300 milligrams in supplements. The total daily intake with proper diet should be at least 500 milligrams. The more fat and sugar in the diet, the more magnesium is needed. The dietary intake of calcium and magnesium should also be balanced. Experts recommend that people should get at least half as much magnesium as calcium in their diet, and some researchers even recommend a 1:1 ratio between calcium and magnesium for supplements. Foods rich in magnesium include: pumpkin and squash seeds, 152mg/ounce; pure bran cereal, 135mg/ounce; almonds, 85 mg/ounce; filberts, 85mg/ounce; cashews, 74mg/ounce; peanuts, 51mg/ounce; oats, 42 mg/ounce; tofu, 29mg/ounce; soybeans, 25mg/ounce.

Drug Interactions:
Magnesium supplements can interact with a number of prescription medications including: digitalis-based heart medications, potassium-sparing diuretics, and blood pressure lowering drugs of the angiotensin-converting enzyme inhibitor type. Consult a physician if requiring magnesium supplements in these cases.

Contraindications:
Do not take magnesium supplements if you have kidney problems or suffer from severe heart failure. Consult a physician if you have had a heart attack before taking magnesium.

Side Effects:
There are no side effects known for magnesium taken at normal dosages. However, too much magnesium (more than 600-700 milligrams daily of elemental magnesium) may cause diarrhea in susceptible persons. Discontinue use if diarrhea develops. Signs of excess magnesium can be similar to magnesium deficiency and include mental status changes, nausea, diarrhea, appetite loss, muscle weakness, difficulty breathing, extremely low blood pressure, and irregular heartbeat.

References:

Ahsan 1997. Metabolism of magnesium in health and disease. Journal of the Indian Medical Association 95(9): 507-10.

Carper, J. 1995. Stop Aging Now. Published by HarperCollins Books, 10 East 53rd Street, New York, New York 10103. Pp. 109-116.

Duke, J. 1997: The Green Pharmacy, The Ultimate Compendium of Natural Remedies from the World’s Foremost Authority on Healing and Herbs. Pp. 121; 134; 144; 146; 149; 163-4; 252; 264; 288-89; 301; 311; 408-409. Rodale Press.

Wilson ML, Murphy PA. 2001. Herbal and dietary therapies for primary and secondary dysmenorrhoea. Cochrane Database Syst Rev 2001; (3): CD002124.

Yades, A.A., Schlicker, S.A. and C.W. Suitor 1998. Dietary Reference Intakes: the new basis for recommendations for calcium and related nutrients, B vitamins and choline. Journal of the American Dietetic Association. 98(6): 699-706.

Positive Clinical Results for Treating Dysmenorroea:
Wilson ML, Murphy PA. 2001. Herbal and dietary therapies for primary and secondary dysmenorrhoea. Cochrane Database Syst Rev 2001; (3): CD002124.

Additional Information:

Calcium and Magnesium Balance
The dietary intake of calcium and magnesium should be balanced. The ratio between calcium and magnesium in the blood is important because too much calcium and too little magnesium makes blood more prone to clotting, which can lead to strokes and heart attacks. Experts recommend that people should get at least half as much magnesium as calcium in their diet, and some researchers even recommend a 1:1 ratio between calcium and magnesium for supplements. Other researchers recommend only 500mg daily.

ABSTRACT (from Medline): Dysmenorrhoea refers to the occurrence of painful menstrual cramps of uterine origin and is a common gynaecological complaint. Common treatment for dysmenorrhoea is medical therapy such as nonsteroidal anti-inflammatories (NSAIDs) or oral contraceptive pills (OCPs) which both work by reducing myometrial activity (contractions of the uterus). The efficacy of conventional treatments such as nonsteroidals is considerable, however the failure rate is still often 20-25%. Many consumers are now seeking alternatives to conventional medicine and research into the menstrual cycle suggests that nutritional intake and metabolism may play an important role in the cause and treatment of menstrual disorders. Herbal and dietary therapies number among the more popular complementary medicines yet there is a lack of taxonomy to assist in classifying them. In the US, herbs and other phytomedicinal products (medicine from plants) have been legally classified as dietary supplements since 1994. Included in this category are vitamins, minerals, herbs or other botanicals, amino acids and other dietary substances. For the purpose of this review we use the wider term herbal and dietary therapies to include the assorted herbal or dietary treatments that are classified in the US as supplements and also the phytomedicines that may be classified as drugs in the European Union.
MAGNESIUM: Three small trials were included that compared magnesium and placebo. Overall magnesium was more effective than placebo for pain relief and the need for additional medication was less. There was no significant difference in the number of adverse effects experienced.
REVIEWER’S CONCLUSIONS: Vitamin B1 is shown to be an effective treatment for dysmenorrhoea taken at 100 mg daily, although this conclusion is tempered slightly by its basis on only one large RCT. Results suggest that magnesium is a promising treatment for dysmenorrhoea. It is unclear what dose or regime of treatment should be used for magnesium therapy, due to variations in the included trials, therefore no strong recommendation can be made until further evaluation is carried out.

Positive Clinical Results (Pregnancy-Related High Blood Pressure):
No authors listed 2002. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial. Lancet 2002 Jun 1; 359(9321): 1877-90

ABSTRACT (from Medline): Anticonvulsants are used for pre-eclampsia (pregnancy-related high blood pressure) in the belief they prevent eclamptic convulsions, and so improve outcome. Evidence supported magnesium sulphate as the drug to evaluate. To test this hypothesis, eligible women where chosen for a study (n=10141). The criteria included: women who had not given birth or were 24 h or less postpartum; blood pressure of 140/90 mm Hg or more, and proteinuria of 1+ (30 mg/dL) or more; and there was clinical uncertainty about magnesium sulphate. Women were randomised in 33 countries to either magnesium sulphate (n=5071) or placebo (n=5070). Primary outcomes were eclampsia and, for women randomised before delivery, death of the baby. Follow up was until discharge from hospital after delivery. Analyses were by intention to treat.
FINDINGS: Follow-up data were available for 10,110 (99.7%) women, 9992 (99%) of whom received the allocated treatment. 1201 of 4999 (24%) women given magnesium sulphate reported side-effects versus 228 of 4993 (5%) given placebo. Women allocated magnesium sulphate had a 58% lower risk of eclampsia (95% CI 40-71) than those allocated placebo (40, 0.8%, vs 96, 1.9%; 11 fewer women with eclampsia per 1000 women). Maternal mortality was also lower among women allocated magnesium sulphate (relative risk 0.55, 0.26-1.14). For women randomised before delivery, there was no clear difference in the risk of the baby dying (576, 12.7%, vs 558, 12.4%; relative risk 1.02, 99% CI 0.92-1.14). The only notable difference in maternal or neonatal morbidity was for placental abruption (relative risk 0.67, 99% CI 0.45-0.89).
INTERPRETATION: Magnesium sulphate halves the risk of eclampsia, and probably reduces the risk of maternal death. There do not appear to be substantive harmful effects to mother or baby in the short term.