Manganese

Manganese is a chemical element with the symbol Mn and atomic number 25. As a free element manganese is a metal.

Manganese is a silvery grey metal resembling iron. It is very hard and brittle.



Discovery of Manganese
Author: Dr. Doug Stewart Manganese compounds have been used since ancient times. The image above (right) shows cave paintings made 16 000 years ago with manganese dioxide. In the first century A.D., Pliny the Elder, the Roman author, described how black powder (manganese dioxide) was used to manufacture colorless glass. (1) It is still used for the same purpose today. The first recognition of manganese's existence as a distinct element was in 1740, when the German chemist, Johann Heinrich Pott, stated that pyrolusite (manganese dioxide) contained a new earth metal. Until then pyrolusite was believed to have been a compound of iron. Pott prepared potassium manganate by fusing caustic potash (potassium hydroxide) with pyrolusite in air. The color changes he observed in the product were green/blue/red/green, establishing that pyrolusite did not contain iron. (2),(2a),(3) Details of the first isolation of metallic manganese were published in 1770 by Ignatius Gottfried Kaim in his dissertation, under the supervision of the chemist Jakab Jozsef Winterl. Working in Vienna, Kaim mixed powdered pyrolusite with twice its weight of black flux and heated the mixture strongly. The composition of Kaim's flux is uncertain, although it was probably based on charcoal. (A flux is a reducing agent.) If so, the reaction would have been: MnO 2 + C → Mn + CO 2 Kaim described the product of the reaction as a blue-whitish shiny brittle metal with many differently shaped facets. When broken and viewed side-on, he observed blue flecks. Kaim claimed that no iron was present in his product, but he was aware his manganese was not pure. He invited other chemists to find a flux that could produce the pure metal. (4), (5) In Sweden, Carl Wilhelm Scheele - the discoverer of chlorine and one of oxygen's independent discoverers - was aware that pyrolusite contained a new element. His attempts to isolate it failed and he asked his friend Johan Gottlieb Gahn to try. Gahn used a similar method to the one Kaim had used a few years earlier, with charcoal as the reducing agent. Gahn used a blowpipe to increase the temperature of the reaction. The metal he produced was white, hard and brittle; when broken it had a granular structure. Gahn's manganese was also impure, but the new metallic element now gained widespread recognition. (2) Manganese's name comes from the use of its compounds in glass-making. These compounds were called 'magnes' in Latin, meaning 'magnet.' (6) Manganese is not actually magnetic!



=Magnesium=

Overview:
Every organ in the body -- especially the heart, muscles, and kidneys -- needs the mineral magnesium. It also contributes to the makeup of teeth and bones. Most important, it activates enzymes, contributes to energy production, and helps regulate calcium levels, as well as copper, zinc, potassium, vitamin D, and other important nutrients in the body. You can get magnesium from many foods. However, most people in the United States probably do not get as much magnesium as they should from their diet. Foods rich in magnesium include whole grains, nuts, and green vegetables. Green leafy vegetables are particularly good sources of magnesium. Although you may not get enough magnesium from your diet, it' s rare to be truly deficient in magnesium. Certain medical conditions, however, can upset the body's magnesium balance. For example, an intestinal virus that causes vomiting or diarrhea can cause temporary magnesium deficiencies. Some gastrointestinal diseases (such as irritable bowel syndrome or IBS and ulcerative colitis), diabetes, pancreatitis, hyperthyroidism (high thyroid hormone levels), kidney disease, and taking diuretics can lead to deficiencies. Too much coffee, soda, salt, or alcohol, as well as heavy menstrual periods, excessive sweating, and prolonged stress can also lower magnesium levels. Symptoms of magnesium deficiency may include agitation and anxiety, restless leg syndrome (RLS), sleep disorders, irritability, nausea and vomiting, abnormal heart rhythms, low blood pressure, confusion, muscle spasm and weakness, hyperventilation, insomnia, poor nail growth, and even seizures.

Uses:
Getting enough magnesium may enhance the effectiveness of conventional treatment for the following conditions: Several studies show that intravenous (IV) magnesium and magnesium inhaled through a nebulizer can help treat acute attacks of asthma in children 6 - 18 years of age, as well as adults. But there is no evidence that taking oral magnesium helps control asthma symptoms. Low levels of magnesium may increase risk of developing asthma. A population based clinical study of more than 2,500 children 11 - 19 years of age found that low dietary magnesium intake may be associated with risk of asthma. The same was found in a group of more than 2,600 adults 18 - 70 years of age. Inadequate magnesium appears to reduce serotonin levels, and antidepressants have been shown to raise brain magnesium. A 2008 study found that magnesium was as effective as the tricyclic antidepressants in treating depression among people with diabetes. People who have type 2 diabetes often have low levels of magnesium in the blood. A large clinical study of over 2,000 people found that getting more magnesium in the diet may help protect against developing type 2 diabetes. Some -- though not all -- studies suggest that taking magnesium supplements may help blood sugar control and insulin sensitivity in people with diabetes or prediabetes. A small preliminary clinical study of 24 people with fibromyalgia found that a proprietary tablet containing both malic acid and magnesium improved pain and tenderness associated with fibromyalgia when taken for at least 2 months. Other studies suggest the combination of calcium and magnesium may be helpful for some people with fibromyalgia. However, a review article evaluating a number of studies found that magnesium with malic acid offered no pain relief. More studies are needed. One study suggests that taking magnesium may prevent temporary or permanent hearing loss due to very loud noise. Magnesium is essential to heart health. Studies suggest a possible association between a modestly lower risk of CHD in men and increased magnesium intake. In one study of women, higher dietary intakes of magnesium were associated with a lower risk of sudden cardiac death. Magnesium helps maintain a normal heart rhythm and is sometimes given intravenously (IV) in the hospital to reduce the chance of atrial fibrillation and cardiac arrhythmia (irregular heartbeat). People with congestive heart failure (CHF) are often at risk for developing cardiac arrhythmia. For this reason, your doctor may decide that magnesium should be a part of the treatment of CHF. One well designed study found that taking magnesium orotate for a year reduced symptoms and improved survival rates compared to placebo in people with CHF. Magnesium and calcium work together at very precise ratios to ensure your heart functions properly. If you have a cardiac history, talk to your doctor before taking magnesium supplements. Results of studies using magnesium to treat heart attack survivors, however, have been mixed. Some have reported lower death rates, as well as fewer arrhythmias and improved blood pressure when magnesium is used as part of the treatment following a heart attack. But one study found that magnesium slightly increased the risk of sudden death, chance of another heart attack, or need for bypass surgery in the year after a heart attack. If you have had a heart attack, your doctor will decide if magnesium supplementation, either IV or orally, is right for you. Eating low fat dairy products, along with lots of fruits and vegetables on a regular basis, is associated with lower blood pressure. All of these foods are rich in magnesium, as well as calcium and potassium. A large clinical study of more than 8,500 women found that a higher intake of dietary magnesium may decrease the risk of high blood pressure in women. A few studies also suggest that magnesium supplements may help lower blood pressure, although not all studies agree. A few studies suggest that taking magnesium supplements may help prevent migraine headaches. In addition, a few clinical studies suggest that magnesium supplements may shorten the duration of a migraine and reduce the amount of medication needed. People who have migraine headaches tend to have lower levels of magnesium compared to those with tension headaches or no headaches at all. Some experts suggest combining magnesium with the herb feverfew along with vitamin B2 (riboflavin) may be helpful when you have a headache. However, some studies suggest that magnesium sulfate may be less effective than prescription medications for preventing migraines in those who have 3 or more headaches per month. The only exception to this may be women who get migraine headaches around the time of their period. Not getting enough calcium, vitamin D, magnesium, and other micronutrients may play a role in the development of osteoporosis. To prevent osteoporosis, it is important to get enough calcium, magnesium, and vitamin D; to eat a well balanced diet; and to do weight bearing exercises throughout life. Preeclampsia is characterized by a sharp rise in blood pressure during the third trimester of pregnancy. Women with preeclampsia may develop seizures, which is then called eclampsia. Magnesium, given in the hospital intravenously (IV), is the treatment of choice to prevent or treat seizures associated with eclampsia or to prevent complications from preeclampsia. Scientific studies suggest that magnesium supplements may help relieve symptoms associated with PMS, particularly bloating, insomnia, leg swelling, weight gain, and breast tenderness. One study suggests that a combination of magnesium and vitamin B6 may work better than either one alone. A small clinical study including only 10 patients found that magnesium improved insomnia related to restless legs syndrome (a disorder characterized by uncomfortable sensations in the legs, which are worse during periods of inactivity or rest or while sitting or lying down).
 * Asthma**
 * Depression**
 * Diabetes**
 * Fibromyalgia**
 * Noise related hearing loss**
 * Arrhythmia and heart failure**
 * High blood pressure**
 * Migraine headache**
 * Osteoporosis**
 * Preeclampsia and eclampsia**
 * Premenstrual syndrome (PMS)**
 * Restless legs syndrome**

Magnesium: What is it?
Magnesium is the fourth most abundant mineral in the body and is essential to good health. Approximately 50% of total body magnesium is found in bone. The other half is found predominantly inside cells of body tissues and organs. Only 1% of magnesium is found in blood, but the body works very hard to keep blood levels of magnesium constant [[|1]]. 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 [[|2-3]]. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes. Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys [[|1-3],[|4]]. 

What foods provide magnesium?
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. Some legumes (beans and peas), nuts and seeds, and whole, unrefined grains are also good sources of magnesium [[|5]]. Refined grains are generally low in magnesium [[|4-5]]. When white flour is refined and processed, the magnesium-rich germ and bran are removed. Bread made from whole grain wheat flour provides more magnesium than bread made from white refined flour. Tap water can be a source of magnesium, but the amount varies according to the water supply. Water that naturally contains more minerals is described as "hard". "Hard" water contains more magnesium than "soft" water.

Eating a wide variety of legumes, nuts, whole grains, and vegetables will help you meet your daily dietary need for magnesium. Selected food sources of magnesium are listed in Table 1. Table 1: Selected food sources of magnesium [[|5]]||~ Food 
 * ~ Milligrams (mg) ||~ %DV* ||
 * Wheat Bran, crude, ¼ cup || 89 || 22 ||
 * Almonds, dry roasted, 1 ounce || 80 || 20 ||
 * Spinach, frozen, cooked, ½ cup || 78 || 20 ||
 * Raisin bran cereal, 1 cup || 77 || 19 ||
 * Cashews, dry roasted, 1 ounce || 74 || 19 ||
 * Soybeans, mature, cooked, ½ cup || 74 || 19 ||
 * Wheat germ, crude, ¼ cup || 69 || 17 ||
 * Nuts, mixed, dry roasted, 1 ounce || 64 || 16 ||
 * Bran flakes cereal, ¾ cup || 64 || 16 ||
 * Shredded wheat cereal, 2 rectangular biscuits || 61 || 15 ||
 * Oatmeal, instant, fortified, prepared w/ water, 1 cup || 61 || 15 ||
 * Peanuts, dry roasted, 1 ounce || 50 || 13 ||
 * Peanut butter, smooth, 2 Tablespoons || 49 || 12 ||
 * Potato, baked with skin, 1 medium || 48 || 12 ||
 * Blackeye peas, cooked, ½ cup || 46 || 12 ||
 * Pinto beans, cooked, ½ cup || 43 || 11 ||
 * Rice, brown, long-grained, cooked, ½ cup || 42 || 11 ||
 * Lentils, mature seeds, cooked, ½ cup || 36 || 9 ||
 * Vegetarian baked beans, ½ cup || 35 || 9 ||
 * Kidney beans, canned, ½ cup || 35 || 9 ||
 * Chocolate milk, lowfat, 1 cup || 33 || 8 ||
 * Banana, raw, 1 medium || 32 || 8 ||
 * Yogurt, fruit, low fat, 8 fluid ounces || 32 || 8 ||
 * Milk chocolate candy bar, 1.5 ounce bar || 28 || 7 ||
 * Milk, lowfat or nonfat, 1 cup || 27 || 7 ||
 * Raisins, seedless, ½ cup packed || 26 || 7 ||
 * Halibut, cooked, 3 ounces || 24 || 6 ||
 * Bread, whole-wheat, commercially prepared, 1 slice || 23 || 6 ||
 * Avocado, cubes, ½ cup || 22 || 6 ||
 * Chocolate pudding, ready-to-eat, 4 ounces || 19 || 5 ||
 * DV = Daily Value. DVs are reference numbers developed by the Food and Drug Administration (FDA) to help consumers determine if a food contains a lot or a little of a specific nutrient. The DV for magnesium is 400 milligrams (mg). Most food labels do not list a food's magnesium content. The percent DV (%DV) listed on the table above indicates the percentage of the DV provided in one serving. A food providing 5% of the DV or less per serving is a low source while a food that provides 10–19% of the DV is a good source. A food that provides 20% or more of the DV is high in that nutrient. It is important to remember that foods that provide lower percentages of the DV also contribute to a healthful diet. For foods not listed in this table, please refer to the U.S. Department of Agriculture's Nutrient Database Web site.

What are the Dietary Reference Intakes for magnesium?
Recommendations for magnesium are provided in the Dietary Reference Intakes (DRIs) developed by the Institute of Medicine of the National Academy of Sciences [[|4]]. //Dietary Reference Intakes// is the general term for a set of reference values used for planning and assessing nutrient intake for healthy people. Three important types of reference values included in the DRIs are //Recommended Dietary Allowances// (RDA), //Adequate Intakes// (AI), and //Tolerable Upper Intake Levels// (UL). The RDA recommends the average daily intake that is sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people. An AI is set when there is insufficient scientific data available to establish a RDA for specific age/gender groups. AIs meet or exceed the amount needed to maintain a nutritional state of adequacy in nearly all members of a specific age and gender group. The UL, on the other hand, is the //maximum// daily intake unlikely to result in adverse health effects. Table 2 lists the RDAs for magnesium, in milligrams, for children and adults [[|4]]. Table 2: Recommended Dietary Allowances for magnesium for children and adults [[|4]]||~ Age (years) (mg/day) ||~ Females (mg/day) ||~ Pregnancy (mg/day) ||~ Lactation (mg/day) || There is insufficient information on magnesium to establish a RDA for infants. For infants 0 to 12 months, the DRI is in the form of an Adequate Intake (AI), which is the mean intake of magnesium in healthy, breastfed infants. Table 3 lists the AIs for infants in milligrams (mg) [[|4]]. Table 3: Recommended Adequate Intake for magnesium for infants [[|4]]||~ Age (months) (mg/day) || Data from the 1999–2000 National Health and Nutrition Examination Survey suggest that substantial numbers of adults in the United States (US) fail to get recommended amounts of magnesium in their diets. Among adult men and women, the diets of Caucasians have significantly more magnesium than do those of African-Americans. Magnesium intake is lower among older adults in every racial and ethnic group. Among African-American men and Caucasian men and women who take dietary supplements, the intake of magnesium is significantly higher than in those who do not [[|6]]. 
 * ~ Males
 * 1–3 || 80 || 80 || N/A || N/A ||
 * 4–8 || 130 || 130 || N/A || N/A ||
 * 9–13 || 240 || 240 || N/A || N/A ||
 * 14–18 || 410 || 360 || 400 || 360 ||
 * 19–30 || 400 || 310 || 350 || 310 ||
 * 31+ || 420 || 320 || 360 || 320 ||
 * ~ Males and Females
 * 0 to 6 || 30 ||
 * 7 to 12 || 75 ||

When can magnesium deficiency occur?
Even though dietary surveys suggest that many Americans do not get recommended amounts of magnesium, symptoms of magnesium deficiency are rarely seen in the US. However, there is concern that many people may not have enough body stores of magnesium because dietary intake may not be high enough. Having enough body stores of magnesium may be protective against disorders such as cardiovascular disease and immune dysfunction [[|7-8]]. The health status of the digestive system and the kidneys significantly influence magnesium status. Magnesium is absorbed in the intestines and then transported through the blood to cells and tissues. Approximately one-third to one-half of dietary magnesium is absorbed into the body [[|9-10]]. Gastrointestinal disorders that impair absorption such as Crohn's disease can limit the body's ability to absorb magnesium. These disorders can deplete the body's stores of magnesium and in extreme cases may result in magnesium deficiency. Chronic or excessive vomiting and diarrhea may also result in magnesium depletion [[|1],[|10]]. Healthy kidneys are able to limit urinary excretion of magnesium to make up for low dietary intake. However, excessive loss of magnesium in urine can be a side effect of some medications and can also occur in cases of poorly-controlled diabetes and alcohol abuse [[|11-18]]. Early **signs of magnesium deficiency** include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures (sudden changes in behaviors caused by excessive electrical activity in the brain), personality changes, abnormal heart rhythms, and coronary spasms can occur [[|1],[|3-4]]. Severe magnesium deficiency can result in low levels of calcium in the blood (hypocalcemia). Magnesium deficiency is also associated with low levels of potassium in the blood (hypokalemia) [[|1],[|19-20]]. Many of these symptoms are general and can result from a variety of medical conditions other than magnesium deficiency. It is important to have a physician evaluate health complaints and problems so that appropriate care can be given. 

Who may need extra magnesium?
Magnesium supplementation may be indicated when a specific health problem or condition causes an excessive loss of magnesium or limits magnesium absorption [[|2],[|7],[|9-11]]. Doctors can evaluate magnesium status when above-mentioned medical problems occur, and determine the need for magnesium supplementation. Table 4 describes some important interactions between certain drugs and magnesium. These interactions may result in higher or lower levels of magnesium, or may influence absorption of the medication.
 * Some medicines may result in magnesium deficiency, including certain diuretics, antibiotics, and medications used to treat cancer (anti-neoplastic medication) [[|12],[|14],[|19]]. Examples of these medications are:
 * Diuretics: Lasix, Bumex, Edecrin, and hydrochlorothiazide
 * Antibiotics: Gentamicin, and Amphotericin
 * Anti-neoplastic medication: Cisplatin
 * Individuals with poorly-controlled diabetes may benefit from magnesium supplements because of increased magnesium loss in urine associated with hyperglycemia [[|21]].
 * Magnesium supplementation may be indicated for persons with alcoholism. Low blood levels of magnesium occur in 30% to 60% of alcoholics, and in nearly 90% of patients experiencing alcohol withdrawal [[|17-18]]. Anyone who substitutes alcohol for food will usually have significantly lower magnesium intakes.
 * Individuals with chronic malabsorptive problems such as Crohn's disease, gluten sensitive enteropathy, regional enteritis, and intestinal surgery may lose magnesium through diarrhea and fat malabsorption [[|22]]. Individuals with these conditions may need supplemental magnesium.
 * Individuals with chronically low blood levels of potassium and calcium may have an underlying problem with magnesium deficiency. Magnesium supplements may help correct the potassium and calcium deficiencies [[|19]].
 * Older adults are at increased risk for magnesium deficiency. The 1999–2000 and 1988–94 National Health and Nutrition Examination Surveys suggest that older adults have lower dietary intakes of magnesium than younger adults [[|6],[|23]]. In addition, magnesium absorption decreases and renal excretion of magnesium increases in older adults [[|4]]. Seniors are also more likely to be taking drugs that interact with magnesium. This combination of factors places older adults at risk for magnesium deficiency [[|4]]. It is very important for older adults to get recommended amounts of dietary magnesium.
 * Symbol:** Mn **Atomic Number:** 25 **Atomic Mass:** 54.93805 amu **Melting Point:** 1245.0 °C (1518.15 K, 2273.0 °F) **Boiling Point:** 1962.0 °C (2235.15 K, 3563.6 °F) **Number of Protons/Electrons:** 25 **Number of Neutrons:** 30 **Classification:** Transition Metal **Crystal Structure:** Cubic **Density @ 293 K:** 7.43 g/cm3 **Color:** silverish/grayish

Atomic Structure

 * [[image:http://www.chemicalelements.com/bohr/b0025.gif width="277" height="275"]] ||  || **Number of Energy Levels:** 4
 * First Energy Level:** **Second Energy Level:** **Third Energy Level:** **Fourth Energy Level:** ||

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * Mn-52 || 5.59 days ||
 * Mn-52m || 21.1 minutes ||
 * Mn-53 || 3700000.0 years ||
 * Mn-54 || 312.2 days ||
 * Mn-55 || Stable ||
 * Mn-56 || 2.57 hours ||
 * Mn-57 || 1.45 minutes ||

Facts

 * Date of Discovery:** 1774 **Discoverer:** Johann Gahn **Name Origin:** From the Latin word //mangnes// (magnet) **Uses:** steel, batteries, ceramics **Obtained From:** pyrolusite, psilomelane, rhodochrosite

 