Manganese is a transition metal with multiple valencies (1, 2, 3, 4, 6 and 7), widely distributed throughout the earth’s crust and present in most plant and animal tissue. As a metal, it is similar to iron and is used industrially in the manufacture of steel, batteries and ceramics. Manganese toxicity among workers in these industries, and in manganese ore miners, is well documented. In addition to its potential for toxicity, manganese is also an essential nutrient. In the human body, it is stored in tissues rich in mitochondria (e.g. the liver and pancreas) and is required for the metabolism of amino acids, proteins, and lipids. Manganese salts have also been used therapeutically, for example in the treatment of psoriasis.
Homeostasis of manganese is by faecal elimination with relatively little appearing in the urine. Hence cholestatic liver disease is associated with manganese retention and toxicity [