Manganese deficiency in humans results in a number of medical problems. Manganese is a vital element of nutrition in very small quantities (adult male daily intake 2.3 milligrams). However, in greater amounts manganese, like most metals, is poisonous when eaten or inhaled.
A deficiency of manganese causes skeletal deformation in animals and inhibits the production of collagen in wound healing.
Manganese is found in leafy green vegetables, fruits, nuts, cinnamon and whole grains. The nutritious kernel, called wheat germ, which contains the most minerals and vitamins of the grain, has been removed from most processed grains (such as white bread). The wheat germ is often sold as livestock feed. Many common vitamin and mineral supplement products fail to include manganese in their compositions. Relatively high dietary intake of other minerals such as iron, magnesium, and calcium may inhibit the proper intake of manganese.
^Food and Nutrition Board, Institute of Medicine. Manganese. Dietary reference intakes for vitamin A, vitamin K, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington, D.C.: National Academy Press; 2001:394-419. (National Academy Press)
^Keen CL, Zidenberg-Cherr S. Manganese. In: Ziegler EE, Filer LJ, eds. Present Knowledge in Nutrition. 7th ed. Washington D.C.: ILSI Press; 1996:334-343.
^Kies C. Bioavailability of manganese. In: Klimis-Tavantzis DL, ed. Manganese in health and disease. Boca Raton: CRC Press, Inc; 1994:39-58.