Chapter 15: Trace Minerals Flashcards
Trace mineral definition
Minerals required in amounts that are <100 mg/d
Functions of iron in the body
Oxygen transport
Energy metabolism
Cell division
Immune system
Nervous system
Role of iron in oxygen transport
- Hemoglobin: iron containing protein in red blood cells
- Myoglobin: iron containing protein in muscles
- RBCs
Role of iron in energy metabolism
Part of enzymes cytochromes needed for energy metabolsim
Role of iron in cell division
Required by an enzyme needed for DNA production
Role of iron in the immune system
Production of WBC and enables some WBC’s to destroy bacteria
Role of iron in the nervous system
Maintain the myelin sheath that covers parts of certain nerve cells
Synthesis of neurotransmitters that regulate brain and muscular activity
What is hemme iron
Form of iron found in meat
Bound to hemme protein
What is nonhemme iron
Not bound to hemme protein
Found in plants and meat
- Grains (enriched)
- Vegetables
- Nuts
- Legumes
What is the transport protein for iron
Transferrin (NOT HEMOGLOBIN)
What is the storage form of iron
Ferritin
Stored in the liver, spleen and bone marrow
Iron absorption from foods
You intake much more nonhemme iron, but more of the hemme iron is absorbed
Bioavailability of non-hemme iron
- Limited absorption
- Factors that enhance absorption: Meat/fish/poultry factor and vitamin C
- Factors that inhibit absorption: phylates and tannins
Bioavailability of hemme iron
Readily absorbed by the body
Factors that enhance iron absorption
Vitamin C
Hemme iron
Leavening of bread
Fermentation
Soaking beans or grains
Iron from cast iron cookware
Factors that inhibit iron absorption
High intake of calcium with iron-containing food
Medications that reduce stomach acidity
Oxalic acid from foods such as spinach
Phytic acid from foods such as whole grains
Soy protein from foods such as tofu
Polyphenols from foods and beverages such as tea
What is anemia
Most common health problem in the US and in the world
Condition where the number of healthy red blood cells are reduced and altered and they are unable to carry adequate amounts of oxygen
Causes of anemia and populations at risk
Causes: blood loss, chronic low intake of iron or low intake during critical periods (adolescence, pregnancy)
At risk: females, vegans
What is microcytic anemia
The 3rd stage of low iron progression
It is iron deficiency anemia
- Characterized by a lack of RBCs or the production of RBCs that do not contain enough hemoglobin
What Myrocytic anemia alter and what are the signs and symptoms
Alters:
- Normal growth
- Behavior
- Immune system function
- Energy metabolism
Signs and Symptoms:
- Fatigue and weakness
- Shortness of breath
- Dizziness / headache
- Coldness in the hands and feet
- Pale skin
What is hereditary hemochromatosis (HH)
an inherited genetic defect that causes people to absorb too much iron (iron toxicity)
Signs and symptoms:
Fatigue, lack of energy, abdominal pain
Function of zinc
Wound healing and immunity (main fxns)
Cofactor for >300 enzymes
Hemme synthesis
DNA and RNA synthesis
Growth and development, reproduction
Bone formation
Immune function
Antioxidant system (superoxide dismutase)
Taste acuity
Good food sources of zinc
Meat (pork/beef/lamb)
Seafood
Enriched, fortified cereals
Dairy (yogurt)
Legumes
Factors that increase zinc absorption
Low to moderate zinc intake
Zinc deficiency
Certain amino acids
Increased need for zinc
Factors that decrease zinc absorption
Phytic acid and fiber in whole grains
Excessive Zinc intake
High nonhemme iron intake
Good zinc status
What happens with zinc deficiency
Delays growth
Delays sex organ maturation
Impairs vitamin A function
Impairs immune function
What is the UL for zinc
40 mg/d
How does zinc toxicity occur and what are the symptoms
Occurs with supplementation
Symptoms:
Diarrhea
Cramps
Nausea & Vomiting
Depressed immune system
Interference with copper absorption and metabolism
Iodine function
Component of thyroid hormones
- thyroxine and triiodothyronine
What is thyroxine ( T4)
Thyroid hormone
Majority
Inactive form
Iodine component
What is triiodothyronine (t3)
The active form of the thyroid hormone with an iodine component
Functions of thyroid hormones
Regulates basal energy expenditure and macronutrient metabolism
Regulates brain and nervous system development
(*think energy metabolism)(impacts almost every physiological process in the body)
Good sources of iodine
Iodized salt, Seaweed
Iodine deficiency disorders
Endemic goiter
Endemic cretinism
Hypothyroidism (low basal metabolic rate)
Function of fluoride
Development of teeth and bone
- forms hydroxyfluorapatite crystals that resist bacteria and acids in the mouth that erode enamel
Good food sources of fluoride
*Fluoridated drinking water
Seafood
Tea
Seaweed
Fluoride deficiency symptoms
Susceptibility to dental caries
- widespread health problems
- leads to nutritional problems due to issues with chewing
Fluoride toxicity
Fluorosis
Function of selenium
Antioxidant function
- prevents free radicals
Assists with the conversion of the thyroid hormone T4 to T3
What minerals have antioxidant functions
Zinc and selenium
Good food sources of selenium
Meat, chicken, fish/seafood
Wheat germ
Eggs
Nuts (Brazil) and seeds (sunflower)
Grains grown in selenium-rich soils or fortified with selenium
Selenium deficiency
Changes in thyroid hormone metabolism
Possible increased cancer risk (because its an antioxidant)
Keshan disease
Selenium toxicity
Selenosis
- impaired sulfur and protein metabolism
- symptoms: nausea, diarrhea, hair loss, fatigue, changes in nails
What is the most common form of cancer
Lung cancer
Definition of cancer
A term for a group of chronic diseases characterized by cells that have undergone mutations
What are malignant cells
Divide repeatedly and frequently
Do not die
Do not perform their specialized function
Risk factors that can cause cells to become cancerous
Aging
Genes/family history
Tobacco use
Radiation exposure
Exposure to certain environmental substances
Certain viral or bacterial infections
Elevated levels of certain hormones
Consuming alcohol or certain foods
Physical inactivity and excess body fat
Role of diet in cancer development
Certain substances in food and beverages promote cancer development
- Alcohol
- Certain molds that can grow on nuts or grains
- Processed or red meats
- Fried, grilled or broiled meats
Excessive energy intake (because eating too much can lead to oxidative stress)
Diet and Health guidelines for cancer prevention
- Choose a diet rich in a variety of plant-based foods, eating plenty of vegetables, fruits and whole grains
- Do not rely on supplements to decrease cancer risk
- Maintain a healthy weight and be physically active
- Drink alcohol only in moderation, if at all
- Select foods low in salt
- Limit intake of red meats
- Avoid sugary drinks and processed meat
- Females who have children: exclusively breastfeed for 6 months
