Iron Flashcards
How much of consumed iron is absorbed?
Very low amounts ~10%
How is non-heme iron absorbed?
What is non-heme iron absorbed as?
By facilitated diffusion
ferrous ions
How is heme iron absorbed?
Vesicle formation
What is removed form heme iron in vesicle formation?
ferrous ions
Heme and Non-heme iron form what to be ferried across the cell and into the blood, via active transport
Ferritin Complexes
What is Non-heme absorption controlled by?
Intestinal Mucosa cells
How do intestinal mucosa cells control the absorption of non-heme iron?
By controlling the amount of iron released in teh blood stream – this is done according to the bodies needs
What influences intestinal mucosa absorption of non-heme iron?
Bodys needs
Hepcidin
Hepcidin?
Hepcidin production is based on?
The effect of Hepcidin is?
nonheme iron regulatory control hormone
produced in the liver based on iron levels and inflammation
Decreased iron absorption
When is the iron absorption downregulated?
When the concentration the body is high
When is iron absorption in the body unregulated?
When the concentration in the body is low
High body iron concentration is known as
Transferrin Saturation
The average absorption rate for iron is about
10%
Absorption of heme iron is effected by dietary components? T/F
F – heme iron is uneffected by dietary components.
absorption of non-heme iron is enhanced by:
Vitamin C
MFP factor (meat pep)
Lactoferrin (breat milk)
Gastric Acid
Non-heme iron absorption is inhibited by:
Phylates Oxalates Polyphenols -- REd wine --Tea --Coffee
How is iron transported?
Bound to transferrin
Most iron absorption occurs in the:
Duodenum/Jejunum
Iron is stored as:
ferritin/hemosiderin
Iron is stored as:
Where is iron stored?
Ferritin/Hemosiderin
In the liver and bone marrow (some in the spleen & muscles)
How is iron lost (excreted)?
- -bleeding/menstruation
- -bile,urine,sweat,fece (1mg/day)
The functions of iron are:
Transport/Storage of Oxygen (Hemoglobin/Myoglobin) Energy Metabolism (Cytochromes) Oxidant production (Immune) Function/Synthesis of Nuerotransmitters DNA synthesis
Primary Sources of Iron:
Liver Beef Chicken Tuna Egg Whole Wheat
Iron toxicity is known as?
Hemachromatosis
Hemachromatosis is..
Excessive iron absorption…
Primary: genetic
Secondary: Hemolytic Anemia due to lacking NADPH so that glutathione cannot be reduced, therefore the cell wall of the RBC is not well protected againts ROS, leading to lysis.
S&S of Iron toxicity (Hemachromatosis):
Fatigue Apathy Increased Risk of Infection Hepatic Pancreatic Cardiac Other Organ damage
Treatment for Iron toxicity (Hemachromatosis):
Phlebotomy/Chelating Agents on a Regular Basis
Do not exceed RDA of rionr
avoid fortified foods, vitamin C and supplements
Prevalence of Iron Deficiency
Most common in the world
Cause of Iron Deficiency
Blood Loss
Medical Condition
Iron-Poor Diets
Patients @ High Risk for Iron Deficiency
Menstruating Women
Pregnant Women
Malabsorption
Inadequate Intake
Treatment for Iron Deficiency
Supplements/Iron Rich Diet
