Manganese is a trace element that is found in some foods, fortified in others and also available as a supplement. It plays an important role in metabolism, bone formation and in the defense of free radicals in the body. Most of the manganese in the body is stored in the bones.
Dietary manganese is found in a wide variety of foods sources. Some of the best sources include almonds, pecans, pinto beans, oatmeal, brown rice, dark chocolate, shellfish, and leafy greens like kale and spinach.
Manganese deficiency is rare in the developed world. While rare, it does carry many side effects including skeletal problems, impaired growth, metabolic and fertility problems and problems maintaining proper glucose levels. Manganese deficiency is most likely to occur when there is an underlying chronic illness such as diabetes, epilepsy or osteoporosis.
Manganese is toxic when consumed in too large amounts. It is also present in some aerosols and metal compounds that can become airborne and be ingested into the lungs. If exposure is at high levels for an extended period of time it can lead to neurotoxicity, symptoms of which can include motor function and psychological problems. If exposure continues it can lead to death.