Approximately half of total body magnesium is found in your bones, the other half existing predominantly inside the cells of body tissues and organs. Marginal magnesium deficiency is thought to be very common, affecting 15 to 20 percent of the population. Deficiency is common in those who eat diets high in processed foods, alcoholics, the elderly, and in those with malabsorption problems.
Magnesium helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate our blood sugar levels, promotes normal blood pressure, and is involved in energy metabolism and protein synthesis. Increasingly, medical literature promotes the use of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes.
Recent European research provides a clue as to the role that magnesium plays in the transmission of hormones such as insulin, thyroid, estrogen, testosterone, DHEA, etc., neurotransmitters such as dopamine, catecholamines, serotonin, GABA, etc., and minerals and mineral electrolytes.
Researchers found that it is magnesium that controls cell membrane potential, thus controlling uptake and release of these hormones, nutrients and neurotransmitters. Magnesium also controls the fate of potassium and calcium in the body. With insufficient amounts of magnesium, potassium and calcium will be lost in the urine and calcium will be deposited in the soft tissues such as the kidneys, arteries, joints, brain, etc.
Magnesium protects our cells from aluminium, mercury, lead, cadmium, beryllium and nickel. Mounting evidence supports that low levels of magnesium contribute to heavy metal deposits in the brain that precede Parkinson's, multiple sclerosis and Alzheimer's. It is also probable that low levels of total body magnesium contribute to heavy metal toxicity in children and contributes to learning disorders.
Most magnesium is absorbed in the small intestine. In a normal person, around half of the amount of magnesium consumed is absorbed. However, this depends on the level of concentration in the diet, with a lower percentage being absorbed from a high magnesium diet. Absorption requires an acidic stomach environment, and is reduced by laxative abuse, infections and allergies. Eating foods that are low in protein or high in phosphorus can also reduce magnesium absorption.
Oxalates, substances found in some green vegetables, and phytates, found in some grains, may form insoluble complexes with magnesium that prevent it from being absorbed. However, these foods are also often high in magnesium, which may compensate for the reduced absorption. Another way to encourage magnesium absorption is to get adequate amounts of vitamin D.
Magnesium deficiency can affect virtually every organ system of the body, and among the symptoms are muscle twitches, cramps, muscle tension, muscle soreness, including back aches, neck pain, tension headaches and jaw joint (or TMJ) dysfunction. Restless leg syndrome is thought to be related to magnesium deficiency. Sighing frequently, feeling tightness in the chest, or the sensation that you can't take a deep breath are also symptoms of magnesium deficiency.
Because insufficient magnesium impairs contraction of smooth muscles, other symptoms include constipation; urinary spasms; menstrual cramps; difficulty swallowing or a lump in the throat, especially after eating sugar; photophobia, particularly having difficulty adjusting to oncoming bright headlights; and sensitivity to loud noises.
The nervous system is significantly affected by a deficiency in magnesium. It can cause insomnia, anxiety, restlessness with constant movement, panic attacks, agoraphobia, and premenstrual irritability, in addition to numbness, tingling, and abnormal sensations, such as zaps and feelings of vibration.
Magnesium has been found to be beneficial in the treatment and prevention of migraine. Belgian researchers assessed the effect of oral magnesium on the prevention of migraine in a study of 81 patients aged from 18 to 65. They were either given a daily supplement of 600 mg of magnesium for 12 weeks, or a placebo. In weeks nine to12, the attack-frequency was 42 percent less in the magnesium group and only 16 percent less in the placebo group. The number of days with migraine and the amount of drugs required per patient were also significantly less in the magnesium group.
The cardiovascular system also relies upon magnesium for proper functioning. Low levels of magnesium have been found in the blood and cardiac muscle of heart attack victims, and magnesium supplements have sometimes been found to be effective in the treatment of high blood pressure. Symptoms of deficiency include palpitations, heart arrhythmias, high blood pressure and mitral valve prolapse. Other general symptoms include a craving for salt, both carbohydrate craving and carbohydrate intolerance, and breast tenderness.
Studies have shown that most people do not generally get sufficient magnesium in their daily diets. Some research has indicated that the RDAs for magnesium may be inadequate, with those who exercise needing up to 500 mg per day. Magnesium requirements are increased during rapid growth in children and adolescents. The RDA for adolescent boys is 410 mg and for girls is 360 mg. Magnesium researcher, Dr. Mildred Seelig, recommends a daily intake of 6 to 10 mg per kg of body weight per day for optimal health.
Consuming a variety of whole grains, legumes, and vegetables every day will help provide adequate intake of magnesium and maintain normal storage levels. Some good sources of magnesium include almonds, avocados, beans, cashews, corn, oatmeal, lemons, and dark green leafy vegetables, such as spinach and collards. Meat is rich in magnesium but it also contains calcium, phosphate and protein, reducing the amount of available magnesium. The refining of foods such as flour, rice and sugar and other methods of food processing remove almost all the magnesium from these foods.
Increasing your dietary intake of magnesium can often help restore mildly depleted levels of magnesium. However, increased dietary intake may not be enough to restore very low magnesium levels to normal, and supplements may be necessary.
Magnesium supplements are available in a variety of forms, including magnesium carbonate, magnesium amino acid chelates, magnesium citrate and dolomite. Organic forms of magnesium, such as citrate, aspartate and fumarate, have better rates of absorption than inorganic forms such as magnesium oxide and magnesium hydroxide, which is why the last two are often used as laxatives. Enteric-coated magnesium supplements may not be as well-absorbed as the magnesium in other types of supplements.
Magnesium supplements are best taken at night, and should not be taken with meals as they neutralise stomach acid, and those with kidney problems and heart disease should not take large doses of magnesium. The suggested ratio of intake of calcium to magnesium is approximately two-to-one although one-to-one may be better. Your health care provider can help you find the right ratio for your needs.