Manganese

About Manganese

Manganese is an essential trace mineral stored mainly in bone, liver, pancreas and brain. An official adequate intake has been set, along with an upper intake level because excess can be neurotoxic. It is a cofactor for enzymes including manganese superoxide dismutase, the main antioxidant enzyme in mitochondria, arginase in the urea cycle, pyruvate carboxylase in gluconeogenesis, and glycosyltransferases that make proteoglycans for cartilage and bone. Dietary deficiency is extremely rare, and experimental deficiency has caused dermatitis, low cholesterol and impaired growth. Toxicity is the greater concern, especially from inhaled dust and fumes in miners and welders, which can cause manganism, a movement disorder resembling Parkinson disease, because manganese accumulates in the basal ganglia. Manganese is eliminated in bile, so cholestatic liver disease raises the risk of buildup, and levels are monitored in long term parenteral nutrition. Iron deficiency increases manganese absorption because both metals share the transporter DMT1.