Nutritional Anemias Flashcards
How does the body rid itself of iron?
It doesn’t have a strong way to do so, eliminating approximately 1 mg/day fecally.
What is the total body iron volume in a person?
3500 mg, stored mostly as hemoglobin
What is the ratio of iron to blood?
I mg Fe++/ mL Blood
Where is ferritin found and what does it do?
Ferritin is a storage molecule for iron, preventing excessive iron in the plasma. It is found the in the liver and spleen
What is myoglobin?
It is the storage molecule of iron found in muscles for use during oxidative stress during exercise.
What is the Labile iron pool?
It is the iron leaving the plasma and entering the interstitial fluid and intracellular fluid compartments
What is transferrin?
It binds to iron in the plasma, producing what we term serum iron. It binds to iron to prevent oxidative species from forming. Turns over 10 times per day, and 1/3rd is saturated with iron at any time.
Which populations should have an increased amount of iron in their diet?
young nonpregnant women, pregnant women and infants
What food has the highest amount of iron that we can consume?
Liver, because that’s where iron is stored. Bread has high levels but we can’t absorb it.
What organ is where iron is absorbed?
Small intestine
On the basement side of the duodenal cell, what helps bring iron into the cell?
FPN, which pumps Fe+++ into the plasma.
How does hepcidin affect FPN?
It eats up the FPN, preventing iron from moving into the plasma. As such, it cannot be there to attach to transferrin and be taken up by organs.
What is FPN?
It is ferroportin, that is the cellular exporter of iron into plasma in intestines. It also is responsible for iron export from macrophages in the spleen and liver. Lastly, assists in delivery of iron to fetus.
What is hepcidin?
Negative regulator of iron uptake, destroying FPN. Also, inhibits hepatocytes that store iron.
What are factors that increase absorption of non-heme iron?
Reducing agents (making it fe++) such as ascorbic acid (vit c) and gastric acids
What are factors that decrease absorption of non-heme iron?
Chelating agents, or tannic acid, tea and calcium
What are factors outside of the GI tract that increase iron absorption?
hypoxia, anemia, depletion of iron stores, increased erythropoeisis
What is the one population that is significantly at risk for iron deficiency in the united states?
Infants because milk is a terrible source of iron.
What are three conditions that can lead to malabsorption of iron?
GI tract surgery
non-tropical sprue
picca
How can GI tract surgery affect iron absorption?
It can lead to removal of the duodenum where iron is absorbed.
What is non-tropical sprue?
Gluten-induced damage to villus epithelial cells of small intestines. Leads to severe malnutrition, steatorrhea, diarrhea, weight loss decreases iron absorption
What ages are commonly affected by non-tropical sprue?
infants until late childhood and against in ones 60s
What is tropical sprue?
Far East, India and Carribean, with overgrowth of coliforms in jejunum. Release of enterotoxin that induces fluid secretion, preventing uptake of folic act and fat.
How do you treat tropical sprue?
Tetracycline and folic acid
What is picca?
Compulsive practice of eating laundry starch. Chelates iron.
What causes GI tract bleeding in the US?
peptic ulcer disease hiatal hernia chronic gastritis due to nsaids hemorrhoids intermitant bleeding after GI surgery neoplams of GI tract
What are causes of GI bleeding in infants?
milk allergy, meckels diverticulum (pancreatic and gastric tissues in small intestins so it has a lot of acid.
What is the leading cause of anemia in premenopausal woman?
Abnormal bleeding, menorraghia
What is the most common cause of GI bleeding int he world?
Hookworm
What is the most common cause of bleeding in the US in men and postmenopausal women?
GI bleeding
What is chlorosis?
Extreme iron deficiency common in olden times for women because they were discouraged from eating meat.
What are the symptoms of chlorosis?
green pallor, breathlessness, palpitations, slight ankle edema, perversion of the appetite, depression, love sick
What are symptoms of iron deficiency?
asymptomatic early on. fatigue, headaches, parathesias,irritability, decreased exercise tolerance, burning tongue, picca
What are physical findings of iron deficiency?
pallor, glossitis, stomatitis, angular chelitis, spoon-shaped fingernails,
How much of the RBC should the central pallor be?
1/3
CBC values that change in iron deficiency?
Decreased MCV, Hmt, increased rdw AND INCREASED TIBC
How do you regulate iron in iron deficiency?
Increased EPO activity and suppressing hepcidin, also increase absorption
What are the different methods of iron administration?
Oral - FeSO4 tablets, abdominal discomfort
Parenterally
- Transfusion - fever, AIDS, anemia,
- Iron Dextran - fever rash, arthralgias
