Abstract
Manganese (Mn) is an essential dietary micronutrient. It is an integral component of various enzymes required for the synthesis of glycosaminoglycans and glycoproteins, which are the key components of connective tissue. Mn also activates prolidase, making proline available for the synthesis of collagen. Together these processes are required for tissue maintenance and wound healing. Mn is also required for energy metabolism, in particular for ATP synthesis. It is a cofactor for various mitochondrial enzymes, including superoxide dismutase, which metabolises superoxide generated during oxygen consumption. These roles of Mn are essential for normal functioning of various organ systems and of the immune system. Whilst Mn deficiency is very rare in patients receiving parenteral nutrition (PN), Mn toxicity is a relatively common complication