Overview:

Manganese is a trace mineral that is present in very small amounts in the body. About 20 milligrams of manganese is found mostly in bones, the liver, kidneys, and pancreas. Manganese aids in the formation of connective tissue, bones, blood-clotting factors, and sex hormones, and plays a role in fat and carbohydrate metabolism, calcium absorption, and blood sugar regulation. Manganese is also necessary for normal brain and nerve function.

Manganese is a component of the antioxidant enzyme manganese superoxide dismutase (Mn-SOD). Antioxidants scavenge damaging particles in the body known as free radicals. These particles occur naturally in the body but can damage cell membranes, interact with genetic material, and possibly contribute to the aging process as well as the development of a number of health conditions. Antioxidants, such as Mn-SOD, can help neutralize free radicals and reduce or even help prevent some of the damage they cause. Damage due to oxidation in the body includes damage to blood vessels (leading to atherosclerosis or hardening of the arteries), increased cholesterol levels, and damage to cells that leads to diseases, including cancer and heart disease.

Low levels of manganese in the body can contribute to infertility, bone malformation, weakness, and seizures. Manganese deficiencies are considered rare, however, since it is relatively easy to obtain adequate amounts of manganese through the diet. Interestingly, though, some experts estimate that as many as 37% of Americans do not get the recommended dietary intake (RDI) of manganese in their diet. This may be due to the fact that whole grains are a major source of dietary manganese, and many Americans consume refined grains (such as white breads and pastas) more often than whole grains. Refined grains only provide half the amount of manganese as whole grains.

However, too much manganese in the diet could lead to increased manganese in the body tissues. Manganese can cause oxidation at high levels in the brain. Abnormal concentrations of manganese in the brain, especially in the basal ganglia, are associated with neurological disorders similar to Parkinson's disease.

Uses:

Supplementing the diet with manganese may be of some benefit for the following illnesses when used in conjunction with conventional medical care:

Arthritis

People with arthritis tend to have low levels of MnSOD (an antioxidant that helps protect the joints from damage during inflammation). Manganese supplementation is thought to increase MnSOD activity. In addition, a few clinical studies of people with rheumatoid and osteoarthritis suggest that the combination of manganese supplementation taken along with glucosamine and chondroitin can reduce pain.

Osteoporosis

Manganese along with other trace elements, such as vanadium and boron, are necessary for bone health. Therefore, many health care professionals feel that appropriate balance and intake of manganese and these other nutrients may play a role in preserving bone density and preventing osteoporosis. Anyone can develop osteoporosis, but it is common in older women. As many as half of all women and a quarter of men older than 50 will break a bone due to osteoporosis.

Diabetes

Although results have been conflicting, some clinical research suggests that people with diabetes have significantly lower levels of manganese in their bodies than people without diabetes. It is not clear, however, whether this is a cause or effect of the condition. In other words, researchers have yet to determine whether diabetes causes levels of manganese to drop or if deficiencies in this trace element actually contribute to the development of the metabolic disorder. In addition, one clinical study found that diabetics with higher blood levels of manganese were more protected from oxidation of low density lipoprotein (LDL, or "bad") cholesterol than those with lower levels of manganese. LDL oxidation contributes to the development of plaque in the arteries (arteriosclerosis) which can lead to heart attack and stroke. Further studies are needed to determine whether supplementation with manganese helps prevent or treat diabetes and its associated complications.

Premenstrual syndrome (PMS)

In one clinical study, women who ate small amounts of manganese (levels below the recommended daily intake) in their foods experienced greater mood swings and cramping pain just prior to their periods than women who ate normal to high amounts of manganese in their foods. These results suggest that a manganese-rich diet may help reduce symptoms of PMS. Another clinical study found that 46 patients with PMS found had significantly lower amounts of calcium, chromium, copper, and manganese in their blood.

Epilepsy

Several clinical studies suggest that manganese levels may be lower in people with seizure disorders. It is not known, however, whether seizures reduce manganese levels or if low manganese levels make a person more susceptible to convulsions. It is also unclear at this time whether manganese supplements would help reduce the number of seizures in people with epilepsy. In fact, at least one animal study suggests that manganese supplementation does not alter the severity or frequency of seizures in rats. At present, there is no satisfactory explanation for the relationship between low manganese levels and the presence of convulsions. More clinical studies need to be performed.

Other

Low levels of manganese have also been associated with muscle disorders that involve lack of coordination, irregular menstrual cycles, tinnitus (ringing in the ears), hearing loss (even in infants), and poor milk production in lactating women.

Dietary Sources:

Rich dietary sources of manganese include nuts and seeds, wheat germ and whole grains (including unrefined cereals, buckwheat, bulgur wheat, and oats), legumes, and pineapples.

Available Forms:

Manganese is available in a wide variety of forms, including manganese salts (sulfate and gluconate) and manganese chelates (aspartate, picolinate, fumarate, malate, succinate, citrate, and amino acid chelate). Manganese supplements can be taken as tablets or capsules, usually along with other vitamins and minerals in the form of a multivitamin.

How to Take It:

The estimated safe and adequate daily intakes (ESSADI) for dietary manganese established by the Food and Nutrition Board of the U.S. National Academy of Sciences are listed below.

In the case of epilepsy and joint inflammation, the recommended dose may be increased under the direction of a health care professional. Supplements and dietary intake of manganese together should not exceed 10 milligrams per day because of the risk of nervous system side effects. Supplementation from non-food sources, particularly for children, should only be taken under the supervision of a health care provider.

Children and Infants

For infants 0 - 6 months: A dietary manganese intake of 0.3 - 0.6 mg daily is recommended.

For infants 7 months - 1 year: A dietary manganese intake of 0.6 - 1.0 mg daily is recommended.

For children 1 - 3 years: A dietary manganese intake of 1.0 - 1.5 mg daily is recommended.

For children 4 - 6 years: A dietary manganese intake of 1.5 - 2.0 mg daily is recommended.

For children 7 - 10 years: A dietary manganese intake of 2.0 - 3.0 mg daily is recommended.

For children 11 - 18 years: A dietary manganese intake of 2.0 - 5.0 mg daily is recommended.

Adult

For adults 19 years and older: A dietary manganese intake of 2.0 - 5.0 mg daily is recommended.

Pregnant women and nursing mothers should avoid intakes of manganese above the upper limit of the estimated safe and adequate daily dietary intake.

Precautions:

Because of the potential for side effects and interactions with medications, dietary supplements should be taken only under the supervision of a knowledgeable health care provider. The amount of manganese ingested in one day (from foods or supplements) should not exceed 10 milligrams due to the potential for nervous system damage.

Calcium, phosphorous, and manganese work closely together in the body. For this reason, dietary requirements of manganese may increase as calcium and phosphorous consumption increases.

Manganese rarely causes side effects when taken orally. It is possible, however, for manganese toxicity to occur in those who regularly inhale manganese vapors, such as industrial workers in steel mills and mines or those people with liver damage, including alcoholic cirrhosis. Potential symptoms of such toxicity include loss of appetite, headaches, leg cramps, muscle rigidity, tremors, convulsions, extreme irritability, acts of violence, and hallucinations. Manganese toxicity has also been seen in individuals who received very high amounts of intravenous nutrition (containing manganese) administered over long periods of time.

Possible Interactions:

If you are currently being treated with any of the following medications, you should not use manganese supplements without first talking to your health care provider.

Haloperidol and other antipsychotics --There has been at least one clinical report of an interaction between haloperidol and manganese that resulted in hallucinations and behavioral changes in a person with liver disease. In addition, some experts believe that medications for schizophrenia and other forms of psychosis may worsen side effects from manganese supplements. Therefore, individuals taking haloperidol or other antipsychotic medications (particularly a class called phenothiazines, which includes chlorpromazine, mesoridazine, perphenazine, prochlorperazine, thioridazine, and trifluoperazine) should use manganese only under the supervision of a qualified health care professional.

Reserpine --Reserpine, a medication used to treat high blood pressure, may decrease manganese levels in the body.

Antacids -- Magnesium-containing antacids, such as aluminum hydroxide/magnesium hydroxide, aluminum hydroxide/magnesium carbonate, and aluminum hydroxide/magnesium trisilicate, may decrease the absorption of manganese if taken together. Take supplements containing manganese at least 1 hour before or 2 hours after taking antacids.

Laxatives -- Magnesium-containing laxatives may decrease the absorption of manganese if taken together. Take supplements containing manganese at least 1 hour before or 2 hours after taking laxatives.

Tetracycline -- The antibiotic tetracycline may reduce the absorption of manganese if taken together. Take supplements containing manganese at least 1 hour before or 2 hours after taking laxatives.