Chapter 12 Flashcards
Trace elements
Iron, zinc, copper, manganese, selenium, iodine, fluoride, chromium, molybdenum
Required by the body in 100mg or less per day
Hemoglobin
An iron containing protein in red blood cells that binds oxygen and transports it through the bloodstream to cells
Transports oxygen to body cells and Carrie’s carbon dioxide away from them for elimination by the lungs
Most of the iron in the body
Heme iron
A readily absorbed form of iron found in animal products that is chemically associated with proteins such as hemoglobin and myoglobin
More efficiency absorbed (2x) than non heme iron
Myoglobin
An iron- containing protein in muscle cells that binds oxygen
Dietary sources of iron
Plant and animal
- meat, fish, poultry
- spinach, potato, whole wheat bread, lentils
Nonheme iron
A poorly absorbed form of iron found in both plant and animal foods that is not part of the iron complex found in hemoglobin and myoglobin
-leafy greens, legumes, whole grains
What type of iron is absorbed more efficiently
Heme iron
Ferritin
Transferrin
The major iron storage protein (in mucosal cells) -excreted in feces
An iron transport protein in the blood to liver, bones and body tissues
Transferrin receptors
Protein found in cell membranes that binds to the iron transferrin complex and allows it to be taken up by cells
Hemosiderin
An insoluble iron storage compound that stores iron when the amount of iron in the body exceeds the storage capacity of ferritin
Iron deficiency anemia
An iron deficiency disease that occurs when the oxygen-carrying capacity of the blood is decreased because there is insufficient iron to make hemoglobin!
-insufficient hemoglobin=red blood cells microcytic and hypo-chromic
- fatigue, weakness, headache, decreased work capacity, inability to maintain body temperature in cold environment
- 80% of world population may be iron deficient and 30% suffer from iron deficiency anemia
Pica
The compulsive ingestion of non food substances such as clay, laundry starch and paint chips
-iron deficiency symptom
Iron toxicity can cause
Iron promotes formation of free radicals and causes cell death due to excess oxidation of cellular components
Iron poisoning—> life threatening
- damage the intestinal lining
- cause abnormalities in body pH, shock and liver failure
- happens slowly over time and accumulated in tissues such as the heart and liver
- most common form of iron overload is hemochromatosis
DO NOT TAKE IRON SUPPLEMENT FOR NO REASON!
Hemochromatosis
An inherited condition that results in increased iron absorption
- weight loss, fatigue, weakness, and immoral pain
- heart and liver damage, diabetes, cancer
Or from taking too many iron supplements
Zinc sources
Plant and animals
- red meat, liver, eggs, dairy, seafood
- veggies
- little in whole grains
Richest sources of zinc are found in animal products!
Metallothionein
Refers to proteins that bind minerals. One such protein binds zinc and/or copper in intestinal cells, limiting their absorption into the blood
Superoxide dismutase
An enzyme that protects the cells from oxidative damage by neutralizing superoxide free radicals. One form of the enzyme requires zinc and copper for activity, and another form requires manganese
Symptoms of zinc deficiency
Poor growth, skin rashes, hair loss, diarrhea, neurological changes, impaired reproduction, reduce immune function
Dietary sources of copper
- organ meats (liver and kidney)
- nuts and seeds
- whole grain breads
- chocolate
- seafood
Ceruloplasmin
The major copper-carrying protein in the blood
-if not bound to protein copper triggers oxidation leading to cellular damage
Copper functions in body
-iron and lipid metabolism enzymes
-connective tissue synthesis
-maintenance of heart muscle
-immune and central nervous system!
-cholesterol and glucose metabolism
-lipid metabolism
-synthesis of neurotransmitters and
blood clotting factors
-prevent certain types of anemia
Copper deficiency causes
- skeleton abnormalities
- impaired growth
- degeneration of heart muscle and nervous system
- decreased immune response
- changes in hair colour and structure
- iron deficiency anemia!
- decreased antioxidants
Dietary sources of manganese
- whole grains
- nuts
- Fruits and leafy greens
Manganese functions
- Manganese requiring enzymes are involved in amino acid, carb, and cholesterol metabolism
- bone formation
- urea synthesis
- antioxidant protection
- oxidative damage prevention
- superoxide dismutase
Selenium dietary sources
-seafood, kidney, liver, eggs, nuts, seeds
Selenoproteins
Proteins that contain selenium as a structural component of their amino acids. Selenium is most often found as selenocysteine, which contains an atom of selenium in place of the sulfur
Glutathione peroxidase
A selenium-contains enzyme that protects cells from oxidative damage by neutralizing peroxides
Selenium deficiency
- muscular discomfort and weakness, cancers, thyroid issues
- Keshan disease: type of heart diseases that occurs in areas of China where the soil is very low in selenium. It is believed to be caused by a combination of viral infection and selenium deficiency. Causes enlarged heart and port heart function.
Iodine dietary sources
- seafood and plants grown near sea
- salt fortified with iodine (iodized salt)
- diary (iodine disinfectants on cows)
Iodine functions
- thyroid gland and thyroid hormones
- thyroid hormones through gene expression promote protein synthesis and regulate basal metabolic rate, growth and development
Thyroid stimulating hormone
A hormone that stimulates the synthesis and secretion of thyroid hormones from the thyroid gland
-if blood levels drop, TSH is released from pituitary gland and stimulates uptake of iodine
Iodine Deficiency
- reduced production of thyroid hormones
- metabolic rate slows and causes fatigue and weight gain
- enlarged thyroid gland-goiter
Consuming diets high in goitrogens (raw cabbage, cauliflower, millet) limit iodine bioavailability - but neutralized by cooking
Goiter
An enlargement of the thyroid gland caused by a deficiency or excess of iodine
Cretinism
A condition resulting from poor maternal iodine intake during pregnancy that causes stunted growth and poor mental development in offspring, spontaneous abortions and still births
Goitrogens
Substances that interfere with the utilization of iodine or the function of the thyroid gland -turnips -rutabaga -cabbage (Less when boiled)
Chromium sources
- liver, brewers yeast, nuts and whole grains
- cooking in stainless steel
Chromium functions
- carbohydrate and lipid metabolism
- increase protein and lipid synthesis
- enhances insulins effect (when chromium is deficient-it takes more insulin to produce same effect)
- requested to maintain normal blood glucose levels
Deficiency of chromium
- impaired glucose tolerance
- elevated blood glucose levels and increased insulin levels
- elevated blood cholesterol and triglyceride levels
(Rare in US)
Fluoride in diet
- fluoridated water
- tea
- marine fish with bones
- topical toothpaste
- in almost all soil, water, plants and animals
Fluoride functions
- reduce dental cavities (makes enamel more acid resistant) by incorporating into crystals in tooth enamel which protects against cavity-causing acids produced by bacteria
- in saliva, decreases bacterial acid production, inhibits dissolution of tooth enamel by acid and increase enamel re-mineralization after acid exposure
- incorporated into crystals in bone and teeth
Fluorosis
A condition caused by chronic overconsumption of fluoride, characterized by black and brown stains and cracking and pitting of the teeth
Molybdenum functions
- needed to activate enzymes
- detoxification
- co factor for enzymes involved in metabolism of sulfur containing amino acids and nitrogen containing compounds (DNA and RNA), production of uric acid, and oxidation/reduction of other compounds
Sources of Molybdenum
Milk, organ meats, breads and legumes
Best understood element and most common nutritional deficiency in Canada
Iron
Iron absorption
- Absorbed into the intestinal mucosal cells
- vitamin C helps absorption
- non heme iron absorption interference: fibre, phytates, oxylates, tannins. Issue for vegans and vegetarians
Iron sources
Red and organ meats, legumes, leafy greens, whole and enriched grains
Zinc functions
- needed for the growth and repair tissues, the activity of the immune system and the development of sec organs and bone
- involved in functioning of >300 different enzymes, including superoxide dismutase, important for protecting cells from free radical damage
- mobilization of vitamin A from liver
- stabilizes cell membranes
- influences hormonal regulation of cell division
- storage and release of insulin
Zinc absorption
- better absorbed from animal sources than plant sources
- can be bound by phytates, affecting bioavailability
Most abundant intracellular trace element
Zinc
Zinc in Canadian diet
- vegetarians and Vegas at risk of inadequate intake
- diet high in phytates, fibre, tannins, oxalates affect zinc
- diet high in nuts=low zinc, Cu upsets balance
Zinc and copper are antagonists to each other
Excess zinc
From supplements causing gastrointestinal irritation, vomiting, appetite loss, diarrhea, abdominal cramps, headaches, decreased immunity, Copper and iron absorption
Zinc fingers and gene expression
Vitamin A and Vitamin D or hormones bind to DNA-binding protein receptor that has zinc fingers that attach to DNA in regulatory regions to help with gene expression
Copper absorption
- zinc antagonizes copper; zinc can decrease the bioavailability of copper
- excess vitamin C decreases Cu absorption
Excess copper
From supplements, copper containers, contaminated water, causing abdominal pain, vomiting and diarrhea
Selenium content of plant foods depends on what
Selenium content of the soil in which the plants grow
Selenium in the body
Incorporated into the structure of certain proteins.
- glutathione peroxidase which decreases oxidative damage
- needed to make thyroid hormones
Where is iodine in the body
-more than 1/2 in the thyroid gland
-regulates metabolic rate, growth and development
Promote protein synthesis
Iodine in the environment
Ocean and sea areas higher in iodine
Depends on soil quantity
Iodine toxicity
Is possible. Do not self medicate for thyroid issues!!!
What reduces bioavailability of fluoride
Calcium rich foods
Fluoride deficiency and excess
Tooth decay
Fluorosis
