Manganese is a mineral that, in very small amounts, is essential for proper functioning of the human body. However, over-consumption can result in nervous system and learning disabilities. Although many whole, natural foods contain manganese, Americans' processed-food diets often result in manganese deficiency.
Manganese is a trace mineral that is present in the human body in very small amounts, primarily in the bones, liver, kidneys and pancreas, according to the University of Maryland Medical School. It is important in the formation of bones, connective tissues, blood-clotting factors and sex hormones, and also is involved in fat and carbohydrate metabolism, calcium absorption and blood sugar regulation. In addition, it is important for brain and nerve function. Manganese may be helpful in treating osteoporosis, arthritis, premenstrual syndrome, diabetes and epilepsy.
Manganese deficiency can lead to infertility, bone malformation, weakness and seizures, reports the University of Maryland Medical Center. Although foods such as nuts, seeds, whole grains, legumes and pineapples are rich sources of manganese, as many as 37 percent of Americans do not get enough of this mineral in their diets. Men age 19 or older should get 2.3 mg of manganese daily and women age 19 or older should get 1.8 mg daily. Women who are pregnant or nursing should get more and children less, depending on age.
Manganese often appears as an ingredient in multivitamins. You may also take it separately in tablet or capsule form. However, combined dietary and supplement manganese intake should not exceed 10 mg per day, states the University of Maryland Medical Center. Adults, and especially children, should consult a medical professional before taking separate manganese supplements.
Although small amounts of manganese are essential for proper body function, people often are exposed to excessive amounts through food, air and water supplies. Vegetarians who eat a lot of grains, beans and nuts, as well as heavy tea drinkers, have higher-than-normal manganese levels in their bodies, and probably don't need supplements, according to the Agency for Toxic Substances and Disease Registry. Welders and people working in the steel industry are often exposed to high levels of manganese. Workers exposed to high levels of manganese often suffer nervous system defects. Children exposed to high levels of manganese often suffer from behavioral problems and a decreased ability to learn and remember.