Fundamentals of Human Nutrition/Magnesium
10.3 Magnesium[edit | edit source]
Magnesium is the twelfth element in the periodic table and is an essential mineral. Magnesium is necessary for proper functioning of the heart, kidneys, and muscles. The word “magnesium” itself comes from the region in Greece, Magnesia, where compounds of it occur naturally. Magnesium is the twelfth element on the periodic table and is presented in symbol form as Mg. The element takes many forms, having both physical and chemical properties. Not only is magnesium the ninth most abundant element in the world, magnesium is very abundant in our own body. On average twenty-five grams of magnesium are present in an adult body, mostly being found in bone and soft tissues. It is also naturally present in several foods, a dietary supplement, and an active ingredient in some medicines. With this, magnesium also plays a role in biochemical reactions, in which it is needed for more than 300 of these. These reactions include: blood glucose control, protein synthesis, nerve function, blood pressure control, and muscle function (NIH.gov, 2013). Currently, it is not recommend to add Magnesium supplements into a regular adults’ daily diet. The body receives adequate amount through dietary sources, although diets high in calcium, protein, or Vitamin D will increase the amount of magnesium needed. Magnesium deficiencies are possible, most occurring from lack of it in one’s daily diet (UMM.edu,2015).
10.3.1 Sources[edit | edit source]
Magnesium is an essential mineral (which means that we should acquire it in our diet because it is not produced naturally by our body) which our body needs so we could maintain efficient muscle and nerve function, for a strong immune system, maintaining healthy heart with normal rhythm, and building strong bones.
The body receives all of its magnesium through one’s daily diet. Since supplements are not required, it is essential that it is received through proper nutrition. The majority of dietary magnesium can be found in plant foods, whereas animal foods often have no magnesium content at all. Magnesium works together with calcium in the body, both creating a balance. If one of these nutrients is in excess or deficient, it is guaranteed the other is as well. Magnesium deficiency symptoms are often seen when there is too much calcium in one’s body. It is important that both nutrients are equally ingested through one’s daily diet, thus promoting the balance between the two. Leafy greens are a vital way to receive adequate amounts of both magnesium and calcium. Nuts ( hazelnuts, pecans, almonds) and legumes (lima beans, soy beans, lentils) are both food sources containing requisite amounts of these nutrients. Interestingly enough, both coffee and cocoa are great sources of dietary magnesium. Cacao just happens to be one of the richest sources of magnesium in the world. Cocoa contains most dietary magnesium when consumed in raw form. This would be in products, such as, cocoa powder and cocoa nibs. Not only is cocoa a great source of magnesium, it also an extreme antioxidant (Onegreenplant,2014).
Most ingredients of our everyday diet have good natural sources of magnesium. Interestingly, various natural sources of magnesium at the same time contain potassium. Examples are Leafy and green vegetables (spinach, broccoli), cereals (oatmeal, barley, crude oat bran, rye, buckwheat, brown rice, unrefined whole wheat grain), milk products (skimmed milk, yogurt), nuts (brazil, almonds, cashews, peanuts, pine, pecans), legumes (kidney beans, soy beans), fruits (bananas, raisins, dates, figs), fish (halibut, broiled and not fried as frying reduces magnesium content), beverages like cocoa and coffee, dried herbs (coriander, chives, spearmint, sage, basil and savory), dried seeds (squash, pumpkin and watermelon), cocoa powder (dark chocolate), flaxseeds, sunflower seeds, sesame seeds, sesame butter (tahini, molasses and dry roasted soybeans.
Herbs, spices, cacao, coffee, nuts, seeds, legumes, milk, whole grains, leafy vegetables, fruits, and fish are sources of magnesium. Generally, sources of fiber are also good sources of magnesium. Table 1 below shows the magnesium content of select foods.
Table 1: Sources of Magnesium3
|Source||Magnesium per 100g of source (%DV)|
|Basil, dried||711 mg (178%)|
|Spearmint, dried||602 mg (151%)|
|Pumpkin seeds, roasted||550 mg (138%)|
|Cacao powder, unsweetened||499 mg (125%)|
|Sage, dried||428 mg (107%)|
|Flaxseed||392 mg (98%)|
|Cumin seeds||366 mg (92%)|
|Chia seeds, dried||335 mg (84%)|
|Sunflower seeds||325 mg (81%)|
|Almonds, roasted||286 mg (72%)|
|Cashews, roasted||273 mg (68%)|
|Dark chocolate, 70-85% cacao||228 mg (57%)|
|Peanuts, roasted||176 mg (44%)|
|Pinto beans||176 mg (44%)|
|Black beans||171 mg (43%)|
|Peanut butter||168 mg (42%)|
|Leeks||161 mg (40%)|
|Kidney beans||160 mg (40%)|
|Soybeans, roasted||145 mg (36%)|
|Whole wheat cereal||121 mg (30%)|
|Spinach, boiled||87 mg (22%)|
|Milk||85 mg (21%)|
|Yogurt||40 mg (10%)|
|Brown rice, long grain||39 mg (10%)|
|Halibut||33 mg (8%)|
|Broccoli, cooked||27 mg (7%)|
|Banana||27 mg (7%)|
10.3.2 Functions[edit | edit source]
Magnesium has been known to help maintain most of the body functions which regulate the vital processes of the heart for a healthy cardiovascular environment and bone density.
Its regulates of blood pressure, reduces the risk of type II diabetes, reduced risk of heart attack and other cardiovascular diseases, reduced risk of osteoporosis,reduced migraine and alleviates the Premenstrual Syndrome (PMS).
Magnesium power our enzymes because it is crucial to more than 300 enzyme-driven biochemical reactions occurring in the body on a near constant basis.
Magnesium drives and maintains the balance of our fuel source because it is a required ingredient of the energy-production process that occurs inside the tiny structures within cells.
Magnesium plays a role in the protection of our DNA as DNA synthesis is slowed by insufficient magnesium.
Magnesium regulates your electrolyte balance. A proper balance of mineral content must be maintained within every cell in the body.
Magnesium contributes in the healthy balance (“homeostasis”) of important minerals (calcium, sodium and potassium) which affects the conduction of nerve impulses, muscle contraction, and heart rhythms.
Over 300 enzymes in the body require magnesium as a cofactor. These enzymes perform a variety of functions, which include including synthesizing protein, maintaining the proper function of nerves and muscles, regulating blood pressure, supporting a healthy immune system, and controlling blood glucose.1,2 Magnesium is essential for glycolysis, energy production, and oxidative phosphorylation.1,2 Additionally, it is necessary for DNA and RNA synthesis as well as the development of bone structure.1,2 Magnesium is also vital for actively transporting potassium and calcium through cell membranes, processes that are vital for the conduction of a nerve impulse, the contraction of muscles, and the regular rhythm of heartbeats.1,2
10.3.3 Requirements[edit | edit source]
Certain nutrients (supplements in particular) and stress conditions increase the need for Magnesium and thus it is very important to monitor one's food consumption and supplement intakes.
When the dietary intake of Magnesium was maintained at 250 mg/day, and Calcium was increased from low (200 mg/day) to high (1400 mg/day), negative Magnesium balance was observed and thus it is very important to increase Magnesium to 500 mg/day when Calcium is present. A negative Magnesium balance was produced when Phosphate PO4 was increased from the near RDA level of 975 mg/day to 1500 mg/day. Vitamin D reduces the Magnesium retention so Vitamin D should be avoided to allow Magnesium to be absorbed by the body.
10.3.4 Imbalance[edit | edit source]
Imbalance or Deficiency in Magnesium leads to the following: low energy, fatigue, weakness, PMS/Hormonal imbalance, inability to sleep, bone weakness, muscle tension/spasm/cramps, abnormal heart rhythm, headaches, anxiousness/nervousness, irritability, kidneys stones, etc.
In individuals with normal kidney function, high doses of magnesium from food sources are not shown to lead to hypermagnesemia, as the kidney maintains a homeostatic level of magnesium.2 However, individuals with reduced kidney function can experience hypermagnesemia from food sources which can lead to serious cardiac and neurological symptoms.2
Nonfood magnesium, such as supplements used for pharmacological purposes, can be associated with negative effects. Excessive magnesium consumption from non-food sources often lead to diarrhea.2 Less common and more serious effects of excess magnesium include: respiratory paralysis, coma, mineral deficiencies, arrhythmia, cardiac arrest, and death.2
Magnesium deficiency as the result of inadequate intake is rare in healthy individuals due to the homeostatic function of the kidney which can prevent the excretion of magnesium in the urine.2 Certain medications (such as diuretics, steroids, certain antibiotics, and chemotherapy drugs), medical conditions (such as diabetes, kidney disease, hyperthyroidism, ulcerative colitis, irritable bowel syndrome, and pancreatitis), alcoholism, and chronically inadequate magnesium intake can lead to deficiencies.4
A magnesium deficiency can result in a variety of symptoms which can include: sleep disorders, agitation, irritability, vomiting, anxiety, hyperventilation, confusion, restless leg syndrome, insomnia, nausea, low blood pressure, arrhythmia, weakness, muscle spasms, and seizures. Serious magnesium deficiency can result in hypocalcemia and hypokalemia.2,4
10.3.5 References[edit | edit source]
1. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Magnesium (1997). In Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, D.C.: National Academy Press. http://www.ncbi.nlm.nih.gov/books/NBK109816/ (Links to an external site.)
2. National Institutes of Health. Office of Dietary Supplements. Retrieved November 30, 2015, from (Links to an external site.)https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ (Links to an external site.)
3. U.S. Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 25. (2012). Retrieved November 30, 2015 from http://www.ars.usda.gov/main/site_main.htm?modecode=80-40-05-25 (Links to an external site.).
4. University of Maryland Medical Center. Magnesium. Retrieved November 30, 2015, from https://umm.edu/health/medical/altmed/supplement/magnesium (Links to an external site.)
5.Magnesium. (2013, November 4). Retrieved December 1, 2015, from https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/#h3
6. Magnesium in diet: MedlinePlus Medical Encyclopedia. (2015, November 19). Retrieved December 1, 2015, from https://www.nlm.nih.gov/medlineplus/ency/article/002423.htm
7. Magnesium. (2015, August 6). Retrieved December 1, 2015, from https://umm.edu/health/medical/altmed/supplement/magnesium
8 . Magnesium: How to Get Enough and Which Foods Are Best. (2014, September 15). Retrieved December 1, 2015, from http://www.onegreenplanet.org/natural-health/magnesium-how-to-get-enough-and-which-foods-are-best/