|Mineral Nutrient :: Manganese|
|Content Below:||What is Manganese · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity|
Manganese is a trace mineral that is vital to life. The human body contains about 15 to 20 milligrams of it. Most of it is found in the bones, with the rest distributed throughout the body in tissues like the pancreas, kidneys, liver, adrenal glands and pituitary glands.
Though manganese is needed in only trace amounts, it is estimated that as much as 1/3 of the North American population do not get enough of it. This is mainly due to the highly processed modern diet that we eat.
A large proportion of the manganese in food is lost in processing. Whole grains, for instance, are foods high in manganese, but refined grains or flour which are much more widely consumed, provide only half the amount.
Manganese is an essential nutrient in many ways. Its key role is in the activation of enzymes that are needed for the digestion and utilization of foods and nutrients.
It also plays a role in reproduction and bone growth. It is sometimes called the ‘brain’ mineral, as it is important to mental function.
The main ways that manganese benefits the body are summarized here.
|::||Manganese Benefits & Functions|
|1.||activates enzymes needed to digest and synthesize fatty acids and cholesterol, and metabolize carbohydrates and proteins|
|2.||important for energy production|
|3.||activates enzymes that enable the utilization of other key nutrients like vitamin B1 (thiamine), biotin, choline, ascorbic acid, and vitamin E|
|4.||manganese-activated enzymes are also important to normal bone and cartilage growth, and keep bones strong and healthy|
|5.||needed for collagen formation in skin cells, which is required for healing of wounds|
|6.||component of metalloenzymes needed for a number of functions that include synthesizing glutamine, and glucose metabolism, which helps regulate blood sugar balance|
|7.||needed to make manganese superoxide dismutase (MnSOD), one of the key antioxidants that protects cells from free radical damage, and so helps maintain a healthy immune system|
|8.||required for production of sex hormones, fertility, reproductive health, and lactation|
|9.||maintains healthy nerves|
|10.||supports optimal function of the thyroid gland and thyroxine production|
|11.||essential for proper iron metabolism and so helps prevent anemia
|12.||works with the B-complex vitamins to generate overall feeling of well-being|
Manganese Deficiency Symptoms and Causes
Full-blown manganese deficiency is very rare and would typically not occur unless manganese is eliminated from the diet. However, many people may not be getting the optimal levels needed for health.
The most common cause of low manganese is poor dietary intake, either due to a diet lacking in manganese food sources, or because of intestinal tract disorders that hinder the absorption of nutrients from food.
Other factors that contribute to manganese deficiency symptoms include :
- excessive sweating, as large amounts of manganese is lost in sweat
- antacids or oral contraceptives interfere with manganese absorption
- iron, copper and magnesium decrease manganese in the body, and excessive intake of any of those minerals can deplete it
- chronic liver or gallbladder disorders may raise intake requirements, as production of enough bile and proper circulation of it is needed for transport of manganese throughout the body
Due to the importance of manganese in enzyme activation, a deficiency can adversely affect many bio-chemical processes in the body.
|::||Manganese Deficiency Symptoms|
|1.||nausea or dizziness|
|5.||iron-deficiency anemia, due to manganese’s role in iron utilization|
|6.||high blood sugar levels (impaired glucose tolerance)|
|7.||blood cholesterol levels that are too low|
|8.||impaired bone growth or skeletal abnormalities, especially in children|
|9.|| excessive bone loss and weak hair and nails
|10.||loss of hair colour|
|11.||defective functioning of the reproductive system|
|12.||severe deficiency in infants can cause convulsions, and even paralysis, blindness and deafness|
Foods high in oxalic acid, like cabbage, sweet potatoes, and spinach, and foods that are high in phytic acid, such as beans, nuts, seeds, soy-based products, and whole grains, may inhibit absorption of manganese slightly. Cooking helps to neutralize that effect.
Foods high in manganese
· dark green leafy vegetables (broccoli, chard, collard greens, kale, mustard greens, romaine lettuce, spinach) · avocados · pineapple · raspberries · nuts (almonds, peanuts, pecans, walnuts).
Other manganese food sources include · bananas, blueberries, figs, grapes, kiwifruit, strawberries · blackstrap molasses · maple syrup · black pepper, cinnamon, cloves, coriander seeds, garlic, peppermint, thyme, turmeric · egg yolks · beets, carrots, sweet potato · asparagus · celery · leeks · summer squash · seaweed · legumes (black beans, chickpeas (garbanzo beans), dried peas, green beans, pinto beans, lima beans, navy beans) · soybeans and soybean products like tofu and tempeh · whole grains (oats, brown rice, rye, whole wheat, quinoa, barley, spelt).
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.
Manganese 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 Manganese as follows.
|Life Stage | Gender||Manganese Dosage | Day|
|Infants 0-6 mths||0.003* mg|
|Infants 7-12 mths||0.6* mg|
|Children 1-3 yrs||1.2* mg|
|Children 4-8 yrs||1.5* mg|
|Girls 9-13 Yrs||1.6* mg|
|Boys 9-13 Yrs||1.9* mg|
|Females 14-18 Yrs||1.6* mg|
|Males 14-18 Yrs||2.2* mg|
|Females 19-50 Yrs||1.8* mg|
|Males 19-50 Yrs||2.3* mg|
|Females older than 50 Yrs||1.8* mg|
|Males older than 50 Yrs||2.3* mg|
|Pregnant Women 14-18 Yrs||2.0* mg|
|Pregnant Women 19-50 Yrs||2.0* mg|
|Lactating Mothers 14-18 Yrs||2.6* mg|
|Lactating Mothers 19-50 Yrs||2.6* 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 Manganese 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
Manganese Overdose Symptoms, Toxicity Level & Side Effects
Moderately high intake of manganese does not normally cause a problem, but excessively high levels pose a risk of toxicity.
Manganese overdose can cause impotency and nervous system disorders similar to Parkinson’s disease. It can also lead to “manganese madness”, characterized by irritability, hallucinations, and violent acts. Excessive levels of manganese tend to deplete copper and iron.
Manganese toxicity can also occur in people with chronic liver disease, as the liver is the means by which the body excretes excess manganese.
Due to the possible serious side effects, the Food and Nutrition Board of the Institute of Medicine has set very conservative Tolerable Upper Intake Levels (ULs) for manganese.
Tolerable Upper Intake Levels (UL) for Manganese per Day
|0 to 12 months||*ND||*ND|
|1 to 3 years||2 mg||2 mg|
|4 to 8 years||3 mg||3 mg|
|9 to 13 years||6 mg||6 mg|
|14 to 18 years||9 mg||9 mg||9 mg||9 mg|
|19 years & above||11 mg||11 mg||11 mg||11 mg|
*ND : Not determinable. Intake should be from food/milk only.
The ULs do not apply to the therapeutic use of manganese 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 vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington, DC: National Academy Press; 2001.|
|2.||Oregon State University, Linus Pauling Institute. Micronutrient Information Center [MIC]: Micronutrient research for optimum health. MIC home page. <http://lpi.oregonstate.edu/infocenter>. Accessed 2009 May.|
|3.||The George Mateljan Foundation: The world’s healthiest foods [WHFoods]. WHFoods home page. <http://www.whfoods.com>. Accessed 2009 March – June.|
|4.||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.|
|5.||Ulene A. Dr. Art Ulene’s complete guide to vitamins, minerals and herbs. New York, NY: Avery Publishing; 2000.|