Magnesium

 

Magnesium Introduction

Magnesium is the third most available mineral in our body. All living cells require this vital mineral for proper functioning. In actuality, it is required for over 300 internal biochemical processes in human physiology alone. Nearly 60 percent of all magnesium in our body lies within our skeletal structures. The remaining magnesium is either directly involved in specific tissue and cell processes, or is found circulating in the blood stream. Interestingly, our bodies contain only one ounce of this major mineral.

B-compound vitamins are a main determinant in the overall absorption of various forms of magnesium. The most common, and most absorbable, forms of magnesium consumed in the diet include:

  • magnesium citrate
  • magnesium gluconate
  • magnesium lactate

The least absorbed form of this mineral is either magnesium oxide or magnesium sulfate. The latter is usually used in popular over-the-counter laxative products.

As critical as magnesium is for the many processes in the human body, it may also be one of the most neglected of all the dietary nutrients regularly consumed. Several studies have suggested that many adults do not consume the recommend daily requirements for magnesium. [1] It is estimated that nearly 75% of all Americans do not get adequate magnesium intakes from their diets. Also as a valid point of reference, is magnesium supplementation in the elderly population.

Persons that are 70 years of age and older tend to be more prone for developing a deficiency state magnesium. Research indicates that this age demographic consumes and absorbs less magnesium than younger adults. [2] This is thought to be caused by the loss of bone density as we age and the many metabolic processes dependant upon magnesium uptake. In addition, persons of African-American decent also consume less magnesium than both Caucasian and Hispanic individuals.

Magnesium is of extreme importance in every structure in the body. It is involved in numerous processes associated with the organs, tooth and bone structure, muscle function, enzyme activity, and the manufacturing of protein and DNA. It also assists in the regulation of other nutrients consumed in the diet; chiefly, calcium, potassium, and Vitamin D.

Magnesium Food Sources

Whole unprocessed food sources represent the best sources of magnesium for dietary consumption. [3] The food table below depicts the amount of magnesium contained (expressed in milligrams) in a given dietary source, and the percentage of recommended daily value fulfilled:

FoodMilligrams%DV*
100 percent Bran, 2 Tbs 44 11
Avocado, Florida, 1/2 med 103 26
Wheat germ, toasted, 1 oz 90 22
Almonds, dry roasted, 1 oz 86 21
Cereal, shredded wheat, 2 rectangular biscuits 80 20
Seeds, pumpkin, 1/2 oz 75 19
Cashews, dry roasted, 1 oz 73 18
Nuts, mixed, dry roasted, 1 oz 66 17
Spinach, cooked, 1/2 c 65 16
Bran flakes, 1/2 c 60 15
Cereal, oats, instant/fortified, cooked w/ water, 1 c 56 14
Potato, baked w/ skin, 1 med 55 14
Soybeans, cooked, 1/2 c 54 14
Peanuts, dry roasted, 1 oz 50 13
Peanut butter, 2 Tbs. 50 13
Chocolate bar, 1.45 oz 45 11
Vegetarian baked beans, 1/2 c 40 10
Potato, baked w/out skin, 1 med 40 10
Avocado, California, 1/2 med 35 9
Lentils, cooked, 1/2 c 35 9
Banana, raw, 1 medium 34 9
Shrimp, mixed species, raw, 3 oz (12 large) 29 7
Tahini, 2 Tbs 28 7
Raisins, golden seedless, 1/2 c packed 28 7
Cocoa powder, unsweetened, 1 Tbs 27 7
Bread, whole wheat, 1 slice 24 6
Spinach, raw, 1 c 24 6
Kiwi fruit, raw, 1 med 23 6
Hummus, 2 Tbs 20 5
Broccoli, chopped, boiled, 1/2 c 19 5

Magnesium Uses

Magnesium is among the most diverse minerals used in human physiology. It provides for a multitude of critical functions and has been used in no fewer than ten clinical applications, relating to the prevention and treatment of various acute and chronic illnesses.

The inclusion of magnesium into dietary supplements containing both calcium and vitamin D may be among its most popular use. These key nutrients are critical in the development, health, and support of bone mineral density. [1] The dietary supplementation of calcium, magnesium, and vitamin D is considered important for the prevention of osteoporosis, and in treatments of the symptoms associated with arthritic condition in older adults (particularly post-menopausal women). [4, 5] Research also suggests that when combined with calcium, magnesium taken during menopause greatly reduces the occurrence of decreased bone mass. [6]

Magnesium supplementation in women has also been used for PMS, mainly to combat the symptoms of weight gain and breast tenderness. [7] Magnesium sulfate has also been administered to pregnant women to prevent complications of preeclampsia. [8] This condition arises during the third trimester of pregnancy and includes an elevation of systolic blood pressures levels that may further enhance the occurrence of seizures (eclampsia). [9]

Another popular topic of research is the physiological affect of low serum magnesium levels. Deficiencies of magnesium may negatively impact the overall health of the cardiovascular system and lead to onset of diseases associated with the heart and circulatory system. Magnesium is also a key component in the regulation of blood pressure.

The dietary supplementation of magnesium in combination with other minerals may lower overall blood pressure levels and reduce the risks for developing hypertension in adults.[10] In fact, the link between high blood pressure and dietary supplementation of magnesium is so compelling, the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of high blood pressure has recommended that person receive adequate daily dietary intakes of magnesium. [11]

Heart disease risk factors relate directly to magnesium levels in the body as well. Surveys have attributed proper magnesium intake for reducing the risks of developing coronary heart disease. [12] Magnesium assists our cardiovascular system by regulating heart rhythms and thinning the blood, thereby decreasing the stressors placed upon the heart. Because of this, lower levels of magnesium in the body may lead to negative metabolic changes in the body. These changes have been suggested to be primary contributors to the elevated risk of heart attacks and strokes. [13]

Carbohydrate metabolism is impacted by our absorption of dietary magnesium. Magnesium exists as a critical component in insulin activity, and may assist in the regulation and control of blood sugar (glucose) levels. [14] Higher levels of sugar in the blood lower the body’s supply of magnesium due to higher urinary excretion rates. Those suffering from either types of diabetes (type I and type II) usually exhibit low levels of magnesium when laboratory tests are conducted. Treatments for symptoms associated with the disease often include this mineral. [15]

The signs and symptoms of a magnesium deficiency have also been found in children suffering from attention-deficit hyperactivity disorder, or ADHD. This has lead to many researches to suggest a possible link between magnesium deficiencies and ADHD in children. In one particular study, over 95 of 100 children studied with ADHD were proven to be magnesium deficient. [16]

Magnesium has also been supplemented in those individuals suffering from certain immunological disorders, primarily HIV and AIDS. Some 30 - 65% of all persons suffering from conditions associated with HIV are said to be deficient in magnesium. [17, 18] Other clinical applications connected to magnesium intake include; asthma, chronic fatigue syndrome, migraine headaches, and inflammatory bowel disorders such as ulcerative colitis. [19, 20]

Magnesium Dosages

The 1999 Recommended Daily Allowances expressed in milligrams (mg): [1]

Life-StageMenWomenPregnancyLactation
Ages 14 - 18 410 mg 360 mg 400 mg 360 mg
Ages 19 - 30 400 mg 310 mg 350 mg 310 mg
Ages 31 + 420 mg 320 mg 360 mg 320 mg

Magnesium Toxicities and Deficiencies

Magnesium Deficiencies

Hypomagnesia: Although many Americans fail to consume the RDA of magnesium, a deficiency in this mineral is unlikely to occur because of its bioavailability in food and water. Signs of a deficiency include; confusion, disorientation, depression, muscle weakness, twitching, cramps, numbness, seizures, and abnormal heart rhythms.

Those individuals with an underlying disease or disorder are especially at risk for the development of a deficiency-related disorder. Alcoholics, those with prolonged diarrhea or vomiting, kidney disease, diabetics are at an elevated risk for developing magnesium deficiency. [21]

Magnesium Toxicities

Hypermagnesia: A toxicity of magnesium is seen primarily in individuals with poor kidney functions. Mega doses of this mineral can lead to Central Nervous System (CNS) disorders such as drowsiness, slurred speech, and decreased tendon reflexes.

Persons taking laxatives or antacids are more likely to develop symptoms of an overdose and/or toxicity, because of the added magnesium (sulfate) in these products. [22] However, diarrhea is the most common reaction from taking these products in excess.

The elderly are especially at risk for the development of a toxicity; this is primarily due to the correlation between age, declined metabolic rates and decreased kidney functioning.

References

1. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. National Academy Press. Washington, DC, 1999.

2. Alaimo K, McDowell, M.A., Briefel, R.R, Bischlf, A.M, Caughman, C.R, Loria, C.M, Johnson, C.L. Dietary Intake of Vitamins, Minerals, and Fiber of Persons Ages 2 Months and Over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91. In: Johnson GV, ed. Vital and Health Statistics of the Center for Disease Control and Prevention / National Center for Health Statistics, Hyattsville, MD 1994:1-28.

3. Clinical Nutrition Service, Warren Grant Magnuson Clinical Center, National Institutes of Health (NIH), NIH. Vitamin E December. 9. 2002. http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

4. Rude RK and Olerich M. Magnesium deficiency: Possible role in osteoporosis associated with gluten-sensitive enteropathy. Osteoporos Int 1996;6: 453-61.

5. Moulin DE. Systemic drug treatment for chronic musculoskeletal pain. Clin J Pain. 2001;17(4 Suppl): S86-S93.

6. Kass-Annese B. Alternative therapies for menopause. Clin Obstet Gynecol. 2000;43(1): 162-183.

7. Pearlstein T, Steiner M. Non-antidepressant treatment of premenstrual syndrome. J Clin Psychiatry. 2000;61 Suppl 12:22- 27.

8. Walker JJ. Pre-eclampsia. Lancet. 2000;356(9237): 1260- 1265.

9. Saunders N, Hammersley B. Magnesium for eclampsia. Lancet.1995; 346(8978): 788-789.

10. Moore TJ. The Role of Dietary Electrolytes in Hypertension. J Am Coll Nutr. 1989; 8(Suppl):68-80S.

11. National Heart, Lung, and Blood Institute. Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Arch Intern Med 1997;157:2413-46.

12. Liao F, Folsom A, Brancati F. Is low magnesium concentration a risk factor for coronary heart disease? The Atherosclerosis Risk in Communities (ARIC) Study. Am Heart J 1998;136:480-90.

13. Altura BM and Altura BT. Magnesium and cardiovascular biology: An important link between cardiovascular risk factors and atherogenesis. Cell Mol Biol Res 1995;41:347-59.

14. Paolisso G, Scheen A, D’Onofrio F, Lefebvre P. Magnesium and glucose homeostasis. Diabetologia 1990;33:511-4.

15. American Diabetes Association. Magnesium supplementation in the treatment of diabetes. Diabetes Care. 1992;15:1065-1067.

16. Kozielec T, Starobrat-Hermelin B. Assesment of magnesium levels in children with attention deficit hyperactivity disorder. Magnes Res. 1997;10(2): 143-148.

17. Patrick L. Nutrients and HIV: part 2-vitamins A and E, zinc, B-vitamins, and magnesium. Alt Med Rev. 2000;5(1):39-51.

18. Skurnik JH, Bogden JD, Baker H. Micronutrient profiles in HIV-1 infected heterosexual adults. J Acquir Immune Defic Syndr. 1996;12:75-83.

19. Cox IM, et al. Red Blood Cell Magnesium and Chronic Fatigue Syndrome. Lancet. Mar 1991;337(8744):757-60.

20. Geerling BJ, Stockbrugger RW, Brummer RJ. Nutrition and inflammatory bowel disease: an update. Scand J Gastroenterol. 1999;34(suppl230):95-105.

21. Herbert, Victor. “Vitamins and Minerals Plus Antioxidant

Supplements” Total Nutrition Ed. Victor Herbert, M.D., Genell J. Subak-Sharpe, M.S. New York: Saint Martin’s Griffin, 1995. 94-118.

22. Qureshi T and Melonakos TK. Acute hypermagnesemia after laxative use. Ann Emerg Med 1996;28:552-5.