NUTR 200 Lecture Notes - Lecture 21: Hypochromic Anemia, Critical Role, Hemoglobin
31 May 2018
School
Department
Course
Professor
NUTR 200 Nutrition for Today 05/14/2018
MJ Gunnarson, MS, RD 1
Trace Minerals – Iron, Iodine, Zinc
Reading
P 311-324
Chapter 14 - Introduction, Iodine…, Iron, Zinc
Objectives for today:
• Explain the importance the intestine in maintaining proper iron levels in the body.
• Describe the changes in red blood cells that occur in iron deficiency
• Explain why iron overload is problematic
• State the role of iodine in the body
• Describe goiter
• Understand the importance of zinc in the body (important in >300 enzymes)
Iron
Food sources
Meats – abundant in heme iron (also contain non-heme iron)
Plant sources –
- only contain non-heme iron
-leafy green veges, beans, enriched grains
-absorbed at less than half the rate of heme iron
-enriched grains
Absorption of iro adjusts to eet the body’s eeds
RDA: 8mg for men, 18mg for women
• Iron released from proteins in foods
– Stomach acid
– Proteases
• Iron absorbed in duodenum
--remember that duodenum is first part of small
intestine but only ~12 inches
– Specific carrier proteins
on enterocytes for heme
and non-heme iron
find more resources at oneclass.com
find more resources at oneclass.com
NUTR 200 Nutrition for Today 05/14/2018
MJ Gunnarson, MS, RD 2
Specific transport protein in blood = transferrin
• Interacts with proteins on cells to deliver iron
Iron storage protein = Ferritin
• Found in every cell, high amounts in liver
Factors that promote absorption
– Stomach acids and protease activity
– Vitamin C
– Iron deficiency
Factors that impair absorption
– Phytates (grains and seeds), oxalate (leafy greens)
– Supplemental Calcium when consumed with an iron containing meal
– Iron overload
What Factors Regulate Total Body Iron?
• Body supply controlled by iron absorption
• individual’s iron status
• the type of iron in foods
• amount of stomach acid for digestion
• dietary factors
• Excretion?
– No excretory pathway (not selectively excreted)
– Very small daily iron losses
• Mainly via cell sloughing (GI tract, skin)
• menstruation
Functions
Component of hemoglobin (oxygen carrying molecule in red blood cells)
Component of myoglobin (oxygen carrying molecule in muscle cells)
Coenzyme involved in energy metabolism of carbohydrates, fats, and proteins, and immunity
Iron Deficiency - can lead to iron deficiency anemia
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Meats abundant in heme iron (also contain non-heme iron) Absorbed at less than half the rate of heme iron. Absorption of iro(cid:374) adjusts to (cid:373)eet the body"s (cid:374)eeds. Rda: 8mg for men, 18mg for women: iron released from proteins in foods. -remember that duodenum is first part of small intestine but only ~12 inches. Specific carrier proteins on enterocytes for heme and non-heme iron. Interacts with proteins on cells to deliver iron. Iron storage protein = ferritin: found in every cell, high amounts in liver. Phytates (grains and seeds), oxalate (leafy greens) Supplemental calcium when consumed with an iron containing meal. Very small daily iron losses: mainly via cell sloughing (gi tract, skin, menstruation. Component of hemoglobin (oxygen carrying molecule in red blood cells) Component of myoglobin (oxygen carrying molecule in muscle cells) Coenzyme involved in energy metabolism of carbohydrates, fats, and proteins, and immunity. Iron deficiency - can lead to iron deficiency anemia.
