Exam 3 - chantel1 Flashcards
What are trace elements? Major concern?
Elements required in trace amounts
>Rate of bioavailability
What are some trace elements?
iron, zinc, copper, iodine, fluoride, chromium, selenium
Where is iron found?
[Fxn?]
Hemoglobin! (in the blood)
[Cellular metabolism]
What are the different types of iron? What affects absorption?
*HEME iron—-found in ANIMAL products, READILY ABSBD form, chemically associated w/ proteins such as hemoglobin and myoglobin
*NON-HEME iron—found in both PLANT and animal foods, POORLY ABSBD form, NOT part of iron complex found in hemoglobin and myoglobin
>VIT C can enhance abspt up to 6x.
>Fiber, phytates, tannins, and oxalates interfere w/ abspt
What is iron deficiency anemia? Symptoms?
Hemoglobin can’t be produced w/ insufficient iron
>RBCs are microcytic and hypochromic—small, pale
>Unable to deliver sufficient O2 to the tissues
> Symptoms related to low blood O2: fatigue, weakness, headache, decreased work capacity, an inability to maintain body temp in cold environment, changes in behavior, and impaired development in infants.
Who Is at Risk for Iron Deficiency?
Women (menstruation), infants/children/ adolescents, and athletes are at higher risk due to increased need and/or poorer food choices
When can iron toxicity occur? How?
UL = 45 mg/day —Impossible to reach by food, possible by supplements
What happens if too much iron is ingested? Effects of iron overload over time?
Life-threatening
>Can damage intestinal lining
>Abnormalities in body pH, shock, and liver failure
Over time, iron
>Accumulates in tissues such as heart and liver
>Contributes to type 2 DM, heart disease, and cancer
*Can only lose iron through losing blood
How does body defend against excess iron?
Mucosal block in intestinal cells offers protection
>Body regulates how much iron is absbed
>If deficient, absb more; otherwise, absb less
To protect against toxic effects of iron, body regulates amount that enters blood from mucosal cells of gastrointestinal tract. This is called a “mucosal block”.
Why is Zinc needed?
> Essential for growth and development
Mainly involved in enzymes–USED IN OVER 300 diff enzymes
»e.g. antioxidant enzyme “superoxide dismutase,” which is vital for protecting cells from free radical damage
What are the different sources of Zinc?
Animal sources– Better absorbed
Plant sources— often bound by phytates
*Zinc is abundant in red meat, liver, eggs, dairy, veggies, some seafood
(Most abundant intracellular trace element)
What is hemochromatosis? Treatment?
genetic disorder in which too much iron is absorbed (excess iron accumulates)
>Mainly afflicts men of white European descent
Treatment: bloodlet (take blood out of them)
Effects of excess Zinc? How do we protect ourselves?
> hair loss
can be toxic!
**decreases bioavailabilty of Cu– can cause copper deficiency, leading to anemia
Protect ourselves by losing zinc when mucosal cell dies
Effects of Zinc deficiency?
> poor growth,
delayed sexual maturation,
skeletal abnormalities,
decreased immunity
Why do we need copper? (Sources?)
Prevents certain types of anemia–transports iron to hemoglobin
(role in connective tissue synthesis)
(Organ meat, seafood, nuts, seeds)
