No guidelines for biological monitoring are available.Īdults: Males: 2.3 mg/day, Females: 1.8 mg/day Respiratory illness and eventually neurological effects are seen after years of heavy exposure. Manganese toxicity is a known problem in metal refining and manganese ore production. Whole blood concentrations of manganese are significantly raised during pregnancy and show an average three-fold increase in the neonate. For whole blood, where the normal concentrations are about ten-fold higher than in serum, the manganese contamination from metal needles is proportionally less significant and so no special precautions are necessary in sampling. We recommend whole blood samples for assessment of manganese status and long-term occupational exposure. 45 During iron deficiency, manganese absorption is increased and so this should be considered in hypermanganesaemic patients. 44 Tissue manganese concentrations are elevated in long-term TPN patients 19 and this has prompted the American Society of Parenteral and Enteral Nutrition (ASPEN) to update their guidelines to indicate that manganese is not supplemented in cholestatic patients. Manganese toxicity can also develop in patients with portosystemic shunts that may ultimately warrant chelation treatment. Brain abnormalities are also visible on magnetic resonance imaging. Its excretion is via the liver into bile and so in some TPN patients, especially those with obstructive liver disease, blood concentrations can increase resulting in tremor and Parkinson's Disease-like symptoms. Deficiency is very rare and blood measurement is usually performed to investigate possible toxicity. It is found in the diet in grains, nuts and tea. Manganese is an essential trace element being required as a co-factor in several enzymes involved in carbohydrate, cholesterol, oxygen radical and nitrogen metabolism. Location in website: Home » Trace Elements » Manganese
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