Types of Magnesium Supplements
There are quite a number of different types of magnesium that are available, including the following:
Magnesium sulfate - magnesium citrate - magnesium oxide - magnesium chloride - magnesium stearate ( usually found as one of the fillers and binders in capsules, but sometimes used as a form of magnesium supplement ) - magnesium hydroxide (used as antacid) - magnesium glycinate - magnesium carbonate - magnesium taurate - magnesium gluconate - magnesium orotate - magnesium L-aspartate hydrochloride, and magnesium lactate.
   Magnesium sulfate (also spelled as magnesium sulphate) is administered intravenously in hospitals.

Which form of magnesium supplement is best?
There is a controversy regarding the ideal form of magnesium mineral to be taken as a supplement. Although there may be variations in absorption rates of different forms of magnesium, I am not sure, for practical purposes, if it makes much of a difference in the long run. Sometimes dosages of supplements that people take are very high, and it may be preferable that less is absorbed. Each case and each person is different, so I can't make any generalizations. One study shows magnesium citrate and magnesium chelate are better absorbed, but red blood cell levels of magnesium were found to be equal with all three forms of magnesium. As you can see by the number of studies listed below, various forms of magnesium appear to have therapeutic benefits.

Magnesium Citrate found more bioavailable than other Mg preparations in a randomised, double-blind study.
Magnes Res. 2003 Sep;16(3):183-91. Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Whiteknights, Reading, UK.
In this 60 day study, the relative bioavailability of three preparations of magnesium (amino-acid chelate, citrate and oxide) were compared at a daily dose of 300 mg of elemental Mg in 46 healthy individuals.Results showed that supplementation of the organic forms of magnesium (citrate and amino-acid chelate) showed greater absorption at 60 days than magnesium oxide. Magnesium citrate led to the greatest mean serum magnesium concentration compared with other treatments. The red blood cell magnesium concentration showed no differences among groups. Chronic magnesium citrate supplementation resulted in the greatest magnesium concentration in saliva.
   My comments: As far as treatment of medical conditions, it appears many different forms of magnesium have similar benefits. A few paragraphs below there is a study regarding the benefit of magnesium oxide for heart failure. Therefore, for practical purposes, I am not sure if one form of magnesium is superior to another form. One option is to take various forms of magnesium supplements as opposed to just one form.

Magnesium Supplement
The most common forms of magnesium that are ingested as supplements include magnesium chelate, magnesium citrate, magnesium aspartate, and magnesium oxide. Magnesium powder is also available for sale.

Food Magnesium
Magnesium rich foods -- Green vegetables such as spinach are good sources of magnesium because the center of the chlorophyll molecule (which gives green vegetables their color) contains magnesium. Other foods high in magnesium include legumes (beans and peas), nuts and seeds. Whole, unrefined grains are also good sources of magnesium. Refined grains are generally low in magnesium. When white flour is refined and processed, the magnesium -rich germ and bran are removed. Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys

Benefit of Magnesium
Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes. Magnesium may even help some individuals who have migraine headaches.

Magnesium oxide and heart failure treatment
Acute and chronic oral magnesium supplementation: effects on endothelial function, exercise capacity, and quality of life in patients with symptomatic heart failure.
Congest Heart Fail. 2006 Jan-Feb;12(1):9-13. Fuentes JC, Salmon AA, Silver MA. Department of Medicine and Heart Failure Institute, Advocate Christ Medical Center, Oak Lawn, IL 60453, USA.
The objective of this study was to determine the effects of acute and chronic oral magnesium supplementation on endothelial function in patients with symptomatic heart failure. Twenty-two symptomatic chronic heart failure patients were randomized to receive 800 mg oral magnesium oxide daily or placebo for 3 months. Patients who received magnesium had improved small arterial compliance at 3 months from baseline compared with placebo.

Magnesium citrate for heart disease
Effects of oral magnesium therapy on exercise tolerance, exercise-induced chest pain, and quality of life in patients with coronary artery disease.
Am J Cardiol. 2003 Mar 1;91(5):517-21. The Heart Institute, Sheba Medical Center, Tel Hashomer, Israel.
Patients with coronary artery disease were randomized to receive either oral magnesium 15 mmol twice daily (Magnosolv-Granulat, total magnesium 365 mg provided as magnesium citrate) or placebo for 6 months. Oral magnesium citrate supplementation in patients with coronary artery disease for 6 months results in a significant improvement in exercise tolerance, exercise-induced chest pain, and quality of life.

Magnesium oxide for heart disease
Oral magnesium supplementation inhibits platelet-dependent thrombosis in patients with coronary artery disease.
Am J Cardiol. 1999 Jul 15;84(2):152-6. Shechter M, Merz CN, Paul-Labrador M, Meisel SR, Rude RK, Molloy MD, Dwyer JH, Shah PK, Kaul S. Preventive and Rehabilitative Cardiac Center, Cedars-Sinai Burns and Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
This study examined whether oral magnesium treatment inhibits platelet-dependent thrombosis (PDT) in patients with coronary artery disease (CAD). In a randomized prospective, double-blind, crossover, and placebo-controlled study, 42 patients with CAD on aspirin received either magnesium oxide tablets (800 to 1,200 mg/day) or placebo for 3 months (phase 1) followed by a 4-week wash-out period, and the crossover treatment for 3 months (phase 2). Oral magnesium treatment inhibited PDT in patients with stable CAD. This effect appears to be independent of platelet aggregation or P-selectin expression, and is evident despite aspirin therapy. These findings suggest a potential mechanism whereby magnesium may beneficially alter outcomes in patients with CAD.

Magnesium and Osteoporosis
A higher intake of magnesium from food and supplements may keep bones healthy as people age, according to results of a study in Journal of the American Geriatrics Society which suggests that greater magnesium intake is significantly related to higher bone mineral density (BMD) in white men and women. According to the paper, there was an approximate 2 percent increase in whole-body BMD for every 100 milligram per day increase in magnesium. Higher magnesium intake through dietary change or supplementation may provide an additional strategy for the prevention of osteoporosis.

A randomized controlled study of effects of dietary magnesium oxide supplementation on bone mineral content in healthy girls.
J Clin Endocrinol Metab. 2006 Oct 3; The Departments of Pediatrics, Internal Medicine, Center for Biomedical Informatics, and the General Clinical Research Center, Yale University School of Medicine, New Haven, CT; The Cooperative Studies Program Coordinating Center, VA Connecticut Healthcare System, West Haven, CT; and Department of Nutrition, Yale-New Haven Hospital, New Haven, CT.
The role of magnesium as a determinant of bone mass has not been extensively explored. Limited studies suggest that dietary magnesium oxide intake and bone mineral density are correlated in adults, but no data from interventional studies in children and adolescents are available. Objective. To determine if magnesium supplementation in peri-adolescent girls enhances accrual of bone mass. Healthy 8-14 yr-old Caucasian girls were recruited from community pediatricians' offices. Dietary diaries from over 120 volunteers were analyzed and those with dietary magnesium oxide intake of less than 220 mg/day were invited to participate in the intervention. Intervention. Magnesium (300 mg elemental Mg per day in 2 divided doses) or placebo, given orally, for 12 months. Main Outcome Measure. The primary outcome measure was interval change in bone mineral content of the total hip, femoral neck, Ward's area and lumbar spine (L1-L4) after 12 months of magnesium oxide supplementation. Significantly increased accrual in integrated hip bone mineral content occurred in the magnesium oxide supplemented vs. placebo group. Trends for a positive magnesium oxide effect were evident in the pre- and early puberty and in mid-late puberty. Lumbar spinal bone mineral content accrual was slightly (but not significantly) greater in the magnesium oxide -treated group. Compliance was excellent; 73% of capsules were ingested as inferred by pill counts. Serum mineral levels, calciotropic hormones, and bone markers were similar between groups. Oral magnesium oxide capsules are safe and well-tolerated. A positive effect of magnesium oxide supplementation on integrated hip BMC was evident in this small cohort.

Magnesium chloride and diabetes
Oral magnesium supplementation improves insulin sensitivity and metabolic control in type 2 diabetic subjects: a randomized double-blind controlled trial.
Diabetes Care. 2003 Apr;26(4):1147-52. Medical Research Unit in Clinical Epidemiology of the Mexican Social Security Institute, Durango, Mexico.
A total of 63 subjects with type 2 diabetes and decreased serum magnesium treated by glibenclamide received either 50 ml magnesium chloride solution (containing 50 g magnesium chloride per 1,000 ml solution) or placebo daily for 16 weeks. Oral supplementation with magnesium chloride solution restores serum magnesium levels, improving insulin sensitivity and metabolic control in type 2 diabetic patients with decreased serum magnesium levels.

Magnesium and Mitral Valve Prolapse
Magnesium may be beneficial in mitral valve prolapse.

Magnesium and Cancer
High levels of magnesium in the diet may lower a woman's risk of developing colon cancer but it is difficult to tell whether the benefit is due to magnesium intake rather than some related factor. Magnesium has been hypothesized to cut the risk of colon cancer by reducing oxidative stress, improving insulin sensitivity, or through mechanisms that reduce proliferation of cells in the colon. SOURCE: American Journal of Epidemiology, February 2006.

A preliminary, controlled investigation of magnesium L-aspartate hydrochloride for illicit cocaine and opiate use in methadone-maintained patients.
J Addict Dis. 2003;22(2):49-61. Margolin A, Kantak K, Copenhaver M, Avants SK. Yale University School of Medicine, Department of Psychiatry, Substance Abuse Center, New Haven, CT 06519, USA.
Eighteen methadone-maintained patients who used illicit opiates and cocaine received either Mg (732 mg/day) or placebo for 12 weeks. The preliminary findings suggest that magnesium may have a beneficial effect for reducing illicit opiate use.

Magnesium deficiency
Severe magnesium deficiency is not common in the United States, however there may be many people who go on with their lives with marginal magnesium deficiency. Early signs of moderate magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency becomes more severe, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur.
   Magnesium deficiency resulting from feeding a diet that has a third of the recommended magnesium intake induces heart arrhythmias, impairs glucose balance, and alters cholesterol metabolism. J Am Coll Nutr. 2007 Apr;26(2):121-32.

Magnesium Orotate
Magnesium orotate dihydrate is poorly soluble in water and hence does not bind gastric acid nor does it exhibit noteworthy laxative effects upon oral administration in contrast to easily dissociable magnesium salts. As a source of magnesium, magnesium orotate is indicated for the oral treatment of extracellular magnesium deficiency. Orotic acid, the second active ingredient of magnesium orotate, is an intermediate in the biosynthetic pathway of pyrimidines and is shown to improve the energy status of injured myocardium by stimulating, a.o., the synthesis of glycogen and ATP. Myocardial energy-rich phosphate levels are decreased during hypoxic conditions; subsequently, intracellular magnesium is depleted and lost via the urine.

Magnesium Research Update
For children who need to go to the ER because of a severe asthma attack, giving them an intravenous infusion of magnesium sulphate along with conventional medications provides an additional benefit.
Dr. D. K. L. Cheuk, at the University of Hong Kong, and colleagues analyzed clinical trials involving a total of 182 children. The studies evaluated the effects of intravenous magnesium sulphate with or without inhaled beta-2-agonist bronchodilators and oral steroid drugs in subjects suffering acute asthma who were seen in the emergency department. The main point was to see if the treatment kept the children from being hospitalized for treatment. "After pooling the results together, intravenous magnesium sulphate was effective in avoiding hospitalization," Cheuk's team reports in the Archives of Disease in Childhood. A significant improvement was also seen with magnesium treatment in short-term lung function tests and symptom scores.

Magnesium intake from food and supplements is associated with bone mineral density in healthy older white subjects.
J Am Geriatr Soc. 2005 Nov;53(11):1875-80. Ryder KM, Shorr RI, Bush AJ, Kritchevsky SB, Harris T, Stone K.
Department of Medicine, Health Science Center, University of Tennessee, Memphis, Tennessee
To determine whether magnesium intake from supplemental and dietary sources is associated with bone mineral density (BMD) in older men and women. Two thousand thirty-eight older black and white men and women aged 70 to 79 at baseline enrolled in the Health, Aging and Body Composition Study. Dietary intake of magnesium was assessed using a semiquantitative food frequency questionnaire, and supplement data were collected based on a medication inventory. BMD of the whole body was obtained using a fan-beam densitometer. Additional covariates included age, body mass index (BMI), smoking status, alcohol use, physical activity, estrogen use, and supplemental calcium (Ca) and vitamin D use. RESULTS: In white, but not black, men and women, magnesium intake was positively associated with BMD of the whole body after adjustment for age, self-report of osteoporosis or fracture in adulthood, caloric intake, Ca and vitamin D intake, BMI, smoking status, alcohol intake, physical activity, thiazide diuretic use, and estrogen use in women. BMD was 0.04 g/cm2 higher in white women and 0.02 g/cm2 higher in white men in the highest than in the lowest quintile of magnesium intake. CONCLUSION: Greater magnesium intake was significantly related to higher BMD in white women and men. The lack of association observed in black women and men may be related to differences in Ca regulation or in nutrient reporting.

Clinical efficacy of magnesium supplementation in patients with type 2 diabetes.
J Am Coll Nutr. 2004 Oct;23(5):506S-509S.
Effects of magnesium (Mg) supplementation on nine mild type 2 diabetic patients with stable glycemic control were investigated. Water from a salt lake with a high natural Mg content (7.1%) (MAG21) was used for supplementation after dilution with distilled water to 100mg/100mL; 300mL/day was given for 30 days. Fasting serum immunoreactive insulin level decreased significantly. There was also a marked decrease of the mean triglyceride level after supplementation. The patients with hypertension showed significant reduction of systolic, diastolic, and mean blood pressure. The salt lake water supplement, MAG21, exerted clinical benefit as a Mg supplement in patients with mild type 2 diabetes mellitus.

[Magnesium as an anti-arrhythmic therapy principle in supraventricular and ventricular cardiac arrhythmias]
Z Kardiol. 1996;85 Suppl 6:135-45.
The use of magnesium as an antiarrhythmic agent in ventricular and supraventricular arrhythmias is a matter of an increasing but still controversial discussion during recent years. With regard to the well established importance of magnesium in experimental studies for preserving electrical stability and function of myocardial cells and tissue, the use of magnesium for treating one or the other arrhythmia seems to be a valid concept. In addition, magnesium application represents a physiologic approach, and by this, is simple, cost-effective and safe for the patient. However, when one reviews the available data from controlled studies on the antiarrhythmic effects of magnesium, there are only a few types of cardiac arrhythmias, such as torsade de pointes, digitalis-induced ventricular arrhythmias and ventricular arrhythmias occurring in the presence of heart failure or during the perioperative state, in which the antiarrhythmic benefit of magnesium has been shown and/or established. Particularly in patients with one of these types of cardiac arrhythmias, however, it should be realized that preventing the patient from a magnesium deficit is the first, and the application of magnesium the second best strategy to keep the patient free from cardiac arrhythmias.

Magnesium emails
Q. What is the best form of magnesium supplement to take?
   A. For practical purposes, I don't think it matters significantly which form of magnesium is used, whether magnesium sulfate - magnesium oxide - magnesium chloride - magnesium glycinate - magnesium carbonate - magnesium taurate - magnesium gluconate.

Q. I notice that the multi vitamin formula contains magnesium oxide. I was reading that magnesium oxide is inferior to other compounds such as chloride and lactate. Is this accurate?
   A. Since there have never been long term human studies comparing the different forms of magnesium, it is premature to say that one form of magnesium is better or inferior than another form.

Q. I recently read a claim that taking the recommended supplementation of 1000-1200 mg Calcium, especially without magnesium supplementation, is too high a dose of calcium and leads to kidney stone, Ca crystal deposits in joints, etc. This source claimed that one should take less Ca and an equal amount of Magnesium ...and if you purchase their newsletter, they will tell you how much of each you should take. Any credence to this? And if so, what is the ratio of Calcium Magnesium? Personally, I do not repect a source that poses such a tease and then doesn't anwer it unless you pay. I appreciate the quality of the information you provide in your newsletter, especially your candor re: evaluation of research data and journal articles. Having been in research, I know the ways data are mainupulated to please funding sources and get grant renewals. Unfortunately, most lay people still view "scientific research" as gospel.
   A. Thank you for your good question. Scientists are still trying to prove that calcium supplements do work to strengthen bones, and this claim seems to have a good confidence of being accurate. We have not seen any studies on the combination of calcium and magnesium to know whether this is better for bones. Since we don't even know the answer to this simple question, it remains to be seen what the ratios should be. There's not enough research to know the ideal calcium magnesium ration. My thought would be if someone were to supplement their diet with calcium and magnesium, an educated guess would be between 500 to 1000 mg of calcium and 100 to 300 mg of magnesium.

Q. I'm confused: can magnesium and calcium be taken together? If they counteract each other, why are there cal/mag supplements? Please advise because I'd like to take magnesium to help my depression and fatigue, but read either contradictory advice as to whether calcium should be taken with it or not.
   A. As a general rule, we don't see why magnesium and calcium can't be taken together.

Q. What is magnesium ascorbyl phosphate"
   A. Magnesium ascorbyl phosphate is a bleaching agent used in cosmetic products.

Q. I saw an article online in which Dr. Sahelian speaks of magnesium for helping reduce hypertension. A Japanese researcher was sited and the magnesium was referred to as mg (OH)2. Could you explain what the OH2 is? I searched but couldn't find an answer. Also, does Dr. Sahelian consider magnesium as the most effective supplement for hypertension? What about hawthorne?
   A. OH2 stands for hydroxide, it is one of the forms magnesium is sold. Magnesium may help some people with high blood pressure but in order to reduce hypertension, a comprehensive dietary and lifestyle program should be initiated.

Q. I have just read some of your e-mails on magnesium and I was wondering what is the difference between magnesium stearate and the other types of magnesium. I used to use magnesium stearate (suggested by a doctor) to help me relax so I could get good sleep. It also helped me with muscle tension and stiffness. Well I can no longer find magnesium stearate. I've tried using magnesium citrate and magnesium oxide but they don't help like the stearate did.
   A. Magnesium stearate is formed by stearate (the anion of stearic acid) and magnesium. Magnesium stearate is used as a filling agent in the manufacture of nutritional tablets since it prevents ingredients from sticking to manufacturing equipment during the making of capsules and tablets. We have not come across magnesium stearate sold as a form of a magnesium supplement in capsule form.

Q. What is the usual starting dose for magnesium supplement?
   A. The usual staring dosage for a magnesium supplement can range from 100 to 200 mg.

Q. You discuss magnesium and it doesn’t matter about what type, but in her book Dr Carolyn Dean M.D. N.D. “ The Miracle Magnesium” says that plenty of research she and others has done tells that magnesium oxide it was found only is absorbed to the tune of about 4% so a 400 mg dose for example would only be about 16 mg absorbed. She says the best is magnesium citrate for bio-availability, so who is right and who isn’t doing research?