11/18 Flashcards
What are trace elements?
Elements Required in amounts
What are examples of trace elements?
iron, zinc, copper, iodine, fluoride, chromium, selenium
Where is iron found?
Hemoglobin! (in the blood)
What are the different types? What affects absorption?
Heme iron—-readily absorbed form of iron found in animal products that is chemically associated with proteins, such as hemoglobin and myoglobin.
Nonheme iron—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.
Vitamin C can enhance nonheme iron absorption up to sixfold.
fiber, phytates, tannins, and oxalates, interfere with the absorption of nonheme iron.
What is iron deficiency?
—Hemoglobin cannot be produced w/ insufficient iron—small, pale, red blood cells.
—-RBCs are microcytic and hypochromic
Unable to deliver sufficient O2 to the tissues
Iron deficiency anemia
=—-Symptoms related to low blood O2
t include fatigue, weakness, headache, decreased work capacity, an inability to maintain body temperature in a cold environment, changes in behavior, and impaired development in infants. -
Who Is at Risk for Iron Deficiency?
Women, infants, children, adolescents, and athletes are all at higher risk of iron deficiency due to increased need and/or poorer food choices
When can iron toxicity occur?
—Upper Limit (UL) has been set at 45 mg/day
—Impossible to reach by food, possible by supplements
What happens if too much iron is ingested?
- —-Life-threatening
- —-Can damage intestinal lining
- —Abnormalities in body pH, shock, and liver failure
Over time— Accumulates in tissues such as the heart and liver
- —-contributes to type 2 DM, heart disease, and cancer
ii. Can only lose iron through losing blood
How does are body recover from excess iron?
Mucosal block in intestinal cells offers protection
i. Body regulates how much iron is absorbed
ii. If deficient, absb more; otherwise, absb less
Why is Zinc needed?
—Essential for growth and development
–Mainly involved in enzymes
–MOST ABUNDANT!!!(:
USED IN OVER 300 different enzymes.
antioxidant enzyme superoxide dismutase, which is vital for protecting cells from free radical damage.
What are the different sources?
animal sources– Better absorbed
plant sources— often bound by phytates.
Zinc is abundant in red meat, liver, eggs, dairy products, vegetables, and some seafood.
What is hemochromatosis?
genetic disease where excess iron accumulates.
- Mainly afflicts men of white European descent
- Treatment: bloodlet (must take blood out of them)
What can excess Zinc cause?
hair loss– can be toxic!
also decreases bioavailabilty of copper– can lead to anemia
What can zinc deficiency cause?
problem with growth, sexual development, skeletal abnormalities, and decreased immunity.
Why do we need copper?
Prevents certain types of anemia– transports iron to hemoglobin
