Manganese (Mn) Flashcards
What dietary factors inhibits Manganese(Mn) absorption?
Fe since it competes for common binding sites with manganese.
After entry into liver via portal circulation, how is Mn transported in the blood?
First in the liver, Mn is oxidized by ceruloplasmin to Mn 3+. Then it complexes with transferrin and transported to other tissue.
True/False: Is 100% of manganese excreted via bile into the feces?
True. Similar to Cu, Mn is excreted via bile but at 100% unlike Cu.
What are the function of Mn?
- Mn functions as a constituent of various metalloenzymes important in urea formation, carbohydrate synthesis and antioxidant properties.
- It is an activator for many enzymes including gluatamine synthetase and glycosyl transferase.
What are good sources of Mn? What is the estimated safe/adequate intake for Mn?
- Nuts, oats, other whole grains.
2. Adequate intakes: 2.2/1.6mg/day M/F 14-18, and 2.3/1.8mg/day M/F for all other groups.
What is the recommended daily parental supplementation dose of Mn for adults?
60 - 100 mcg/day
What are some symptoms of Mn deficiency?
Poor reproductive performance, congenital abnormalities in offspring, abnormal bone and cartilage formation, ataxia (defective muscular coordination, growth retardation, and defects in CHO and lipid metabolism.
What are some symptoms of Mn toxicity?
Severe abnormalities of the central nervous system including hyper-irritability, violent acts, hallucinations, disturbances of libido, and ataxia.
Who is at risk for developing Mn toxicity?
Pts on long-term parenteral nutrition who develops obstruction of the biliary duct and are unable to excrete Mn.
What is the estimated upper tolerable/safe doses for Mn?
Up to 10mg/day of Mn via oral route is considered safe.
How do we assess Mn status?
Monitor whole blood Mn levels s best and cost effective way to asses Mn status because levels correlate well with MRI abnormalities (which is expensive).
