|Mineral Nutrient :: Magnesium|
|Content Below:||What is Magnesium · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity|
Magnesium is an essential macro-mineral, which means we need to take in a few hundred milligrams of it each day. It is the fourth most abundant mineral in our bodies.
As with all the other minerals it cannot be made in the body, but must be consumed from foods containing magnesium. It is absorbed in the small intestines, and excreted via the kidneys, which control blood levels of it.
Of the 25 grams or so of magnesium in an adult body, 60-65% is found in the bones, about 25% in muscles, and the rest in tissues and body fluids.
Different types of foods contain different forms of magnesium. Where it is present mainly in water-soluble form, as in vegetables and beans, cooking and processing can significantly reduce its content. Milling of cereal grains removes about 80% of its magnesium content, as most of it is located in the germ and outer layers of the grains.
In industrialized countries which rely to a great extent on processed food, the average diet may not have enough foods high in magnesium, to cater for optimal health. While full-blown deficiency is rare, many people have sub-clinical deficiency and show some magnesium deficiency symptoms.
The importance of magnesium to overall health has been rather underrated till recently. However, research now shows that magnesium benefits many of the body’s functions, and plays a vital role in healing.
For a start, it is required for proper functioning of over 300 different types of enzymes. These enzymes are needed to trigger bio-chemical reactions in the body that are essential to life.
As a result, the impact of this mineral is so wide that practically all body systems – our brain, heart, bone, nerve, muscle, liver, kidneys, hormonal, and digestive systems – are affected by any magnesium deficiency.
The main ways that magnesium benefits the body are summarized here.
|::||Magnesium Benefits & Functions|
|1.||affects the metabolism of other essential nutrients like potassium, calcium, and vitamin D|
|2.||plays a major role in the formation of healthy bones and teeth, giving bone its physical structure together with calcium and phosphorus|
|3.||growing evidence that magnesium taken together with calcium and potassium may help minimize bone loss and prevent osteoporosis, including after menopause|
|4.||involved in over 300 enzyme reactions, including those needed for forming bone matrix and for protein synthesis|
|5.||vital to enzyme activity for fat and carbohydrate metabolism, and so plays a major role in production and transport of energy|
|6.||since the 1990’s there is evidence that magnesium supplementation can improve insulin sensitivity in diabetics and help regulate blood sugar level|
|7.||needed to regulate neuro-muscular transmission and muscle relaxation and can help treat muscle cramps|
|8.||studies suggest that magnesium supplemention may help constipation predominant irritable bowel syndrome by helping to relax the muscles in the intestinal walls|
|9.||keeps blood circulating smoothly, regulates normal heart rhythm, and is used to treat arrhythmia (irregular heartbeat)|
|10.||relaxes muscles and nerves and promotes healthy blood pressure (as evidenced in some studies)|
|11.||lowers risk of cardiovascular or coronary heart disease and stroke|
|12.||vital in protecting the artery linings from stress caused by sudden blood pressure changes|
|13.||protects against immune dysfunction|
|14.||appears to alleviate PMS (PMT) symptoms like mood swings, tenderness in the breasts, bloating, and swollen legs|
Magnesium Deficiency Symptoms and Causes
Although outright magnesium deficiency is rare, there is concern over the prevalence of sub-optimal levels of magnesium. It is possibly one of the most under-diagnosed nutrient deficiencies in the developed world. Many people are not eating enough foods high in magnesium, and don’t achieve the optimal level that is needed to protect against a number of disorders, such as those of the heart and neuro-muscular systems.
Deficiency or hypomagnesemia (low blood levels of magnesium) can be due to any of a variety of reasons. These include :
- a diet that is short of foods containing magnesium
- a diet high in fats, protein, zinc or vitamin D
- foods high in oxalic acid such as almonds, cashews, chard, celery, cocoa, kale, spinach, tea, also interfere with absorption
- digestive tract problems such as inflammatory bowel diseases and ulcerative colitis that hinders absorption of nutrients from food
- low blood levels of calcium
- presence of fluoride
- emotional or physical stress including trauma, burns or surgery
- liver diseases
- chronic or excessive vomiting or diarrhea
- diabetes or other kidney diseases (healthy kidneys control urinary excretion of magnesium to compensate for any deficit)
- use of prescription medication such as diuretics (drugs that increase urine output), antibiotics (like neomycin, tetracycline, erythromycin, sulfamethoxazole, and the sulfonamides), the corticosteroids, oral contraceptives, and the anticoagulant drug warfarin
Due to the wide impact of this mineral on the body, magnesium deficiency symptoms vary widely.
|::||Magnesium Deficiency Symptoms|
|1.||overactivation of nerve and muscle impulses, leading to tremors or hyperexcitability or irritability and nervousness|
|2.||muscle weakness, twitching or spasm, cramp, fatigue|
|3.||mental confusion, disorientation, or apathy|
|4.||magnesium deficiency is known to inhibit vitamin D metabolism and cause calcium depletion, leading to low levels of calcium in the blood (hypocalcemia), and softening and weakening of bones, and is a risk factor for postmenopausal osteoporosis|
|5.||linked to low blood levels of potassium (hypokalemia)|
|6.||increased risk of abnormal heart rhythms, and greater risk of stroke and complications after a heart attack|
|7.||elevated blood pressure|
|8.||insulin resistance linked to blood sugar imbalances and type 2 diabetes|
|9.||loss of appetite, headaches, nausea, vomiting|
|10.||studies show migraine sufferers tend to have lower magnesium levels|
|12.||disturbed sleep or insomnia or sleepiness|
|13.||poor memory and reduced learning ability|
|14.||changes to the heart, resulting in increased heartbeat or abnormal heart rhythms (arrhythmia) in cases of more severe deficiency|
|15.||in cases of severe lack of magnesium, deficiency symptoms can include muscle contractions, tingling or numbness|
|16.||severe deficiency can also cause seizures, delirium and hallucinations|
|17.||some studies showed that children with attention deficit hyperactivity disorder (ADHD) tended to have mild magnesium deficiency; those given magnesium supplements in addition to their ADHD medication displayed significantly decreased hyperactivity|
Foods high in magnesium are
· rice bran, wheat bran · peas and beans (legumes) such as black beans, black-eyed peas, green beans, green peas, kidney beans, lentils, lima beans, navy beans, pinto beans, french beans · whole grains (such as brown rice, buckwheat, millet, oats, quinoa, wheat) · whole grain products (like whole-grain cereals, buckwheat flour, rye flour) · nuts (like almonds, cashews, peanuts) · seeds such as pumpkin seeds, sesame seeds, sunflower seeds, flax seeds, mustard seeds · most dietary magnesium comes from vegetables, especially dark green, leafy vegetables such as spinach, swiss chard, kale, mustard greens, turnip greens, broccoli, collard greens.
Other foods containing magnesium include · apricots, figs, raisins · avocados, bananas · basil, cloves, coriander seeds, ginger root, mustard seeds, peppermint · beets, Brussel sprouts, cabbage, carrots, cauliflower, celery, cucumber, potatoes (baked with skin), summer squash, tomato (ripe) · blackstrap molasses · brewer’s yeast · dairy foods such as milk and yogurt · kelp · meat · seafood such as halibut, salmon, tuna, scallops and shrimp · soybeans and soy products like soymilk and tofu · wheat germ.
Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins. They work synergistically, which means that the effectiveness of any one nutrient requires, or is enhanced, sometimes dramatically, by the presence of certain other nutrients.
For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs.
For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible.
Keep in mind, however, that while mineral supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle.
Magnesium RDA (Recommended Dietary Allowance)
The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Magnesium as follows.
|Life Stage | Gender||Magnesium Dosage | Day|
|Infants 0-6 mths||30* mg|
|Infants 7-12 mths||75* mg|
|Children 1-3 yrs||80 mg|
|Children 4-8 yrs||130 mg|
|Girls 9-13 Yrs||240 mg|
|Boys 9-13 Yrs||240 mg|
|Females 14-18 Yrs||360 mg|
|Males 14-18 Yrs||410 mg|
|Females 19-30 Yrs||310 mg|
|Males 19-30 Yrs||400 mg|
|Females older than 30 Yrs||320 mg|
|Males older than 30 Yrs||420 mg|
|Pregnant Women 14-18 Yrs||400 mg|
|Pregnant Women 19-30 Yrs||350 mg|
|Pregnant Women 31-50 Yrs||360 mg|
|Lactating Mothers 14-18 Yrs||360 mg|
|Lactating Mothers 19-30 Yrs||310 mg|
|Lactating Mothers 31-50 Yrs||320 mg|
These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Magnesium toxicity levels.
1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram
1 mg = 1 milligram = 1/1,000 of a gram
* Indicates AI figures based on Dietary Reference Intake (DRI) figures
Magnesium Overdose Symptoms, Toxicity Level & Side Effects
Magnesium at normal levels, or from food, has few to no side effects. Any excess is typically from supplementation or medication. Even then, effects of magnesium toxicity is not common, as the body removes excess through the kidneys.
However too much magnesium from extremely big doses can cause serious
The most common symptom of magnesium toxicity is diarrhea, which is usually linked with doses upwards of 1000 milligrams, though it has been known to happen at lower doses than that.
Other signs of too much magnesium range from depression to confusion, to unusual drowsiness, nausea, vomiting, muscular weakness, lowered blood pressure, difficulty breathing, irregular heartbeat, and even cardiac arrest, coma and death in extreme cases.
The Food and Nutrition Board of the Institute of Medicine has set Tolerable Upper Intake Levels (ULs) for magnesium. These are levels above which there is risk of magnesium toxicity, especially when taken over a long time.
Tolerable Upper Intake Levels (UL) for Magnesium per Day
|0 to 12 months||*ND||*ND|
|1 to 3 years||65 mg||65 mg|
|4 to 8 years||110 mg||110 mg|
|9 to 13 years||350 mg||350 mg|
|14 years & above||350 mg||350 mg||350 mg||350 mg|
*ND : Not determinable. Intake should be from food/milk only.
These ULs are for magnesium from supplements alone, excluding the intake from water and foods containing magnesium for which no upper limit is set. They do not apply to therapeutic use of magnesium for treatment, which should be under the supervision of a healthcare professional.
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|1.||Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for calcium, phosphorous, magnesium, vitamin D, and fluoride. Washington DC: National Academy Press; 1997.|
|2.||U.S. National Libary of Medicine [NLM] & National Institutes of Health [NIH]: MedlinePlus. NLM-NIH home page. <http://www.nlm.nih.gov/medlineplus>. Use the built-in search function to find specific data. Accessed 2009 March – June.|
|3.||National Institutes of Health, NIH Clinical Center: Office of Dietary Supplements [ODS]. ODS home page. <http://ods.od.nih.gov>. Use the built-in search function to find specific data. Accessed 2009 Mar – Jun.|
|4.||The George Mateljan Foundation: The world’s healthiest foods [WHFoods]. WHFoods home page. <http://www.whfoods.com>. Accessed 2009 March – June.|
|5.||Mayo Foundation for Medical Education and Research. Mayo Clinic book of alternative medicine: The new approach to using the best of natural therapies and conventional medicine. New York, NY: Time Inc; 2007. p 67-75.|
|6.||Balch JF, Balch PA. Prescription for nutritional healing: A practical A-Z reference to drug-free remedies using vitamins, minerals, herbs & food supplements. Garden City Park, New York: Avery Publishing; 1990.|
|7.||Ulene A. Dr. Art Ulene’s complete guide to vitamins, minerals and herbs. New York, NY: Avery Publishing; 2000.|
|8.||Starobrat-Hermelin B, Kozielec T. The effects of magnesium physiological supplementation on hyperactivity in children with attention deficit hyperactivity disorder (ADHD). Positive response to magnesium oral loading test. Magnes Res. 1997 Jun; 10(2):149-56.|