NUTR100 Lecture Notes - Lecture 19: Iron-Deficiency Anemia, Selenium Deficiency, Iron Overload
13 Jun 2018
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Chapter 12 Trace Elements
- Includes iron, zinc, copper, manganese, selenium, iodine, fluoride, chromium,
molybdenum
- Required in amounts less than 100 mg per day
- Have been difficult to study, as difficult to remove from the diet
- Rate of bioavailability is a concern for trace elements
Iron
- Hemoglobin is the iron containing component of the blood
- Iron from animal products is heme iron( more efficient absorbed than non heme iron)
- Iron from plants is nonheme iron
o Iron cookware can be a source of non heme iron in the diet
- Iron from the diet is absorbed into the intestinal mucosal cells
- Heme proteins absorbed as heme group and non heme iron is absorbed in ferrous form
- Some iron is bond to feratin, when mucosal cells die it is secreted in feces
o Iron enters blood and converted to Feric form, binds to transferrin
o When red blood cells die are broken down by the liver
- Can be toxic in high amounts
o Ferritin is the major iron storage protein, levels can be used to estimate iron
stores. Deficiency signs shown only after stores are depleted
o Transferin: iron transport protein in the blood
o Hemosiderin is an insoluble iron storage compound produced by the body
- Women who take oral contraceptives lose 60% less blood each motnh so lower iron
needs
- Deficiency
o Hemoglobin is not produced
o With insufficient hemoglobin, red blood cells are microcytic and hypochromic
and unable to deliver sufficient oxygen to the tissues. Iron deficiency anemia
o Symptoms: fatigue, weakness, headache, inability to maintain body temp,
adverse pregnancy outcomes, Pika: apetite for non nutritive substances
o As uh as 80% of orld’s populatio is defiiet, 30% ith aeia
- Sources: heme iron is in red meats, leafy green vegetables
- Iron toxicity and Overload:
o Essential for cellular metabolism, can be toxic, causes cell death from too much
oxidation
o UL of 45 mg/day from all sources
o Iron poisoning can be life threatening, can damage the intestinal lining and cause
abnormalities in the body pH, shock and liver failure
o Iron overload can happen overtime and accumulates in tissues such as the heart
and liver
o Most common form is hemochromatosis: inherited condition with increased iron
absorption, most common genetic disorder in Caucasian population
Zinc
- Animal products, in some vegetables, whole grains,
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Includes iron, zinc, copper, manganese, selenium, iodine, fluoride, chromium, molybdenum. Required in amounts less than 100 mg per day. Have been difficult to study, as difficult to remove from the diet. Rate of bioavailability is a concern for trace elements. Hemoglobin is the iron containing component of the blood. Iron from animal products is heme iron( more efficient absorbed than non heme iron) Iron cookware can be a source of non heme iron in the diet. Iron from the diet is absorbed into the intestinal mucosal cells. Heme proteins absorbed as heme group and non heme iron is absorbed in ferrous form. Some iron is bond to feratin, when mucosal cells die it is secreted in feces. Iron enters blood and converted to feric form, binds to transferrin: when red blood cells die are broken down by the liver. Can be toxic in high amounts: ferritin is the major iron storage protein, levels can be used to estimate iron stores.
