FSN Chapter 15
What functions in the boy are zinc dependent?
-Cofactor to many enzymes -DNA synthesis and function
What is hemochromatosis?
-Genetic disease -Iron deposit that can lead to organ damage -May go undetected until organ damage at 50-60
What are some common functions of Fe in the body?
-Hemoglobin in red blood cells -Transports oxygen and carbon dioxide -High turnover, high demand for iron -Myoglobin in muscle cells
What is fluorosis and what is it caused by?
-mottled enamel -caused by overexposure to fluoride
What diseases are associated with selenium deficiency?
Keshan disease, a disease characterized by insufficient cardiac function
What are some symptoms of zinc deficiency and why are mild deficiencies difficult to detect?
The symptoms include loss of appetite, delayed growth and sexual maturation, dermatitis, impaired vitamin A function, alopecia, decreased taste sensitivity, poor wound healing, immune dysfunction, severe diarrhea, birth defects, and increased infant mortality.
What are some common food sources for zinc?
animal-based food such as beef, land, and pork. plant-based foods, such as nuts, wheat, and whole grains
Why is iodine deficiency still prevalent in many areas of the world today?
approximately 30% of households worldwide still do not have access to iodized salt
Why are children at risk for Fe toxicity?
children are ore vulnerable to iron poisoning then adults because their absorptive mechanisms cannot respond as rapidly as those of an adults. The primary cause of iron overload in children is the consumption of excess chewable iron-containing supplements
What factors increase and decrease iron absorption?
heme iron is absorbed much more readily than non-heme iron and is not highly affected by dietary composition
What is America's major source of fluoride?
the major source of fluoride is fluoridates water
What are some symptoms of iodine deficiency?
the thyroid gland enlarges in an attempt to increase its efficiency at trapping iodine. The characteristic enlargement of the thyroid gland that occurs is called a goiter
Good food sources of copper.
liver, shellfish, nuts, seeds, lentils, soy products, and dark chocolate. Dried fruits, whole-grain products, and the tap water
Common dietary Fe sources (heme and non-heme)
-In animal flesh (beef, pork, seafood, and poultry), most of the iron is present as hemoglobin and myoglobin, which collectively is called heme iron. -Heme iron: Iron provided from animal tissues primarily as a component of hemoglobin and myoglobin. Approximately 40% of the iron in meat is heme iron; it is readily absorbed. -In addition to the iron in foods, iron cookware can contribute to iron intake. When foods are cooked in iron pans, small amounts of iron from the cookware are transferred to the food. Acidic food, such as tomato sauce, increases the amount of iron transferred from the cookware to the food and, in turn, increases the total iron content.
What population groups are at greatest risk of Fe deficiency anemia?
-Infant, toddler, chronic blood loss, vegans, runners, and women of childbearing age -Pica in women and children (craving for nonfood stuff: dirt, clay)
What are factors that can affect zinc absorption?
-Influenced by the foods consumed -Animal sources are better absorbed -Dependent on body's needs -Factors that decrease absorption: Presence of phytic acid (unleavened bread), Competes with copper and iron for absorption, Calcium supplements
RDA and UL for Fe.
-RDA is 8 mg/day for adult male -RDA is 18 mg/day for females age 19-50 -UL: 45 mg/day
What are some factors that affect Fe absorption?
-form of iron in foods eaten -the titan amount of iron present in the diet -diet composition -the acidity of the gastric contents
Describe the stages of Fe deficiency.
Marginal or Early Iron deficiency: -decrease iron intake -increase iron losses -decrease iron stores -increase transferrin receptors -no apparent symptoms Moderate Iron Deficiency: -depleted iron stores -decrease work/exercise capacity -decrease immune function -decrease iron transport Severe Iron deficiency, Iron Deficiency Anemia: -decrease hemoglobin and red blood cells synthesis (anemia) -decrease oxygen transport -increase fatigue -poor work/exercise performance -increase incidence of infection -decrease growth and cognitive development in children -increase morality
What is superoxide dismutase and how does zinc affect this enzyme?
enzyme that deactivates a superoxide free radical. SOD can contain the trace minerals copper and zinc or or manganese
What is the main function of iodine?
iodine is an essential component of the thyroid hormones thyroxine and triiodothyronine
Explain the importance of metallothionein.
protein involved in the binding and release of zinc and copper in intestinal and liver cells
What is the importance of fluoride in the human body?
role in supporting the deposition of calcium and phosphorus in teeth and bones in protecting against the development of dental carries
Common food sources of iodine.
saltwater, seafood, seaweed, iodized salt, and dairy products are the best sources of iodine
Know some common food sources of selenium in foods.
seafood, meats, cereal and grains
