Manganese citrate, manganese gluconate, manganese sulfate
Manganese is an element, but is referred to in nutritional terms as a mineral. Manganese is concentrated in the mitochondria of cells, and is most prevalent in bone, liver, pancreas, and kidney cells. The lower the serum levels of manganese, the more efficiently it is absorbed by the body.
Manganese is important for normal growth and development, but the minimal dietary requirement for manganese is easily met. Manganese is abundant in plants and grains.
Manganese is a structural component of several enzymes and also helps activate other enzymes. One important enzyme is manganese superoxide dismutase (MnSOD). This enzyme helps maintain mitochondrial and cell membranes by scavenging free radicals that can damage the lipids (fats) in the membrane.
Medically valid uses
Normal levels of manganese in the bloodstream are important for normal growth and development. In addition, the enzyme MnSOD acts as a powerful antioxidant by getting rid of free radicals that damage cell membranes.
Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.
Manganese may help maintain normal bone density in post-menopausal women, potentially decreasing the risk for osteoporosis. Its use in osteoarthritis and rheumatoid arthritis has also been proposed. Research has shown that people with epilepsy often have low blood manganese levels. Manganese deficiency in rats has been linked to an increase in convulsions similar to those seen in epilepsy.
It has also been suggested that manganese plays a role in glucose tolerance. Maintaining an adequate dietary intake of manganese may be beneficial for people with diabetes.
Research is investigating the possibility that manganese can prevent some types of cancer.
There is no Recommended Dietary Allowance (RDA) or Dietary Reference Intake (DRI) for manganese. The Estimated Safe and Adequate Daily Dietary Intake (ESADDI) is 2 to 5 mg/day for adults; this amount is found in the average diet.
Manganese is available as an individual supplement and as a component of some multivitamin-mineral formulas. Manganese supplements are available as manganese gluconate, manganese sulfate, or manganese citrate, although manganese gluconate may be less irritating to the stomach.
The best sources of manganese include whole grains and cereals, nuts and seeds, leafy vegetables, avocados, and seaweed. The manganese content of some of these foods is listed in the table below.
Wheat germ (1/4 cup)
Rye flour (dark, 1 cup)
Whole wheat flour (1 cup)
Seaweed (agar, dried, 3.5 oz)
Pecans (dried, 1 oz/ 31 nuts)
Spinach (boiled, cup)
Avocado (1 medium)
Manganese deficiency does not develop in humans unless manganese has been deliberately omitted from the diet. Manganese is abundant in plants and very adequately meets the body's low requirement for manganese. In fact, manganese is absorbed more efficiently when intake of manganese is low.
Symptoms of manganese deficiency are hard to identify but may include growth retardation (in young humans and animals), bone deformities (in animals), abnormal glucose levels, changes in glucose tolerance, and abnormal cholesterol levels. Other symptoms of deficiency may include a change in hair or beard color.
In animals, manganese deficiency leads to reproductive difficulties, abnormal muscle coordination in infant offspring, skeletal and cartilage abnormalities, and impaired glucose tolerance.
Side effects, toxicity, and interactions
Signs of dietary manganese excess are hard to detect but include poor appetite, depressed growth, possible reproductive failure and anemia (because manganese competes with iron for absorption).
Serious effects have been documented in patients receiving total parenteral nutrition (TPN, or intravenous feeding) or in individuals with abnormal liver function who are taking oral supplements of manganese.
These effects include:
Impaired motor skills
Irreversible nerve damage with symptoms resembling Parkinson's disease
Manganese is extremely toxic when inhaled as manganese oxide from dust or fumes.
Some well water can also be contaminated with manganese.
People with liver dysfunction should avoid manganese supplements.
Women who are pregnant or breastfeeding should consult a physician before taking any mineral supplements.
Manganese competes with iron for absorption. Manganese absorption can be decreased by the presence of fiber, phytates, oxalic acid, calcium and phosphorus. It is inconclusive whether or not zinc and copper absorption may be decreased by manganese.
A relationship may exist between manganese and schizophrenia or other neuropsychiatric diseases. However, evidence remains theoretical that abnormal manganese metabolism may contribute to the onset of schizophrenia.
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