Micronutrients and Trace Elements Flashcards Preview

Dems Unit 2 Part 2 YAAAY > Micronutrients and Trace Elements > Flashcards

Flashcards in Micronutrients and Trace Elements Deck (73):
1

function of iron

-oxygen transport in blood/ muscle
-electron transport

2

function of iodine

thyroxine (T4)
triiodothyronine (T3)

ability of thyroid gland to concentrate iodine

3

function of zinc

-gene expression
-zinc metalloenzymes
-cell membrane structure/ fxn
-induce metallothionein synthesis

4

function of copper

oxidative enzymes

5

function of selenium

-important antioxidant
-glutathione peroxidase
-thyroid function ( interaction with I)

6

function of molybdenum

xanthine oxidase
sulfite oxidase

7

function of manganese

-mitochondrial SOD
-CHO metabolism
-mucopolysaccharide synthesis

8

function of chromium

-facilitates binding of insulin to receptors

9

function of fluoride

integrity of teeth/ skeleton

10

function of cobalt

structure of cobalamin b12

11

heart failure, anorexia, slow growth

severe iron deficiency

12

anemia, impaired cognitive development, decreased exercise tolerance

mild iron deficiency

13

hypothyroidism

severe iodide deficiency

14

goiter

mild iodide deficiency

15

spontaneous abortion, cretinism, deafness, mental retardation

fetus iodide deficiency

16

acro-orficial dermatitis, diarrhea, increased infections, poor wound healing, delayed sexual maturations, personality changes

severe zinc deficiencies

17

growth retardation, anorexia, increased infections

mild zinc deficiency

18

intra-uterine growth retardation, congenital malformations

fetus zinc deficiency

19

mental retardation, seizures, connective tissue defects, fractures

severe copper deficiency

20

anemia, neutropenia, osteoporosis, seborrheic skin lesions

mild copper deficiency

21

connective tissue defects baby

fetus copper deficiency

22

cardiomyopathy, skeletal myopathy

severe selenium deficiency

23

macrocytosis, loss of hair pigment, hypothyroidism

mild selenium deficiency

24

sources of iron

Heme Iron:
-Cellular animal protein
Non-heme Iron:
-legumes, nuts, whole grains

25

Iron Absorption:
Dietary Factors:
insoluble complexes

phytate, tanins

26

Iron Absorption:
Oxidation state

-ascorbic acid: Fe3+ --> Fe2+
-absorption enhanced for reduced state

27

Iron Absorption:
Mineral Mineral Interactions

-excessive Zn or Cu decreases Fe absorption

28

Iron Absorption:
Host Factors 2

1. Fe deficiency --> increased absorption
2. inflammation--> increased hepcidin from liver --> decreased absorption at enterocyte

29

Iron Absorption:
Quantity in Gut lumen

inverse relationship

30

main site of iron regulation

intestinal absorption

31

major route of iron loss

bleeding

32

major iron stores

liver, bone marrow, spleen

33

Iron transport and storage form

transport: transferrin
Storage: ferritin/ hemosiderin

34

most common nutritional deficiency in the world

iron

35

iron deficiency in men or post-menopausal women

merits investigation for source of bleeding

36

iron deficiency manifestation

-Anemia: microcytic, hypochromic
-W.o anemia: impaired cognitive function, growth

37

iron deficiency diagnosis

Severe Deficiency:
-low Hb/Hct & microcytic/ hypo chromic rbc

Mild, moderate/ Severe Defic:
-low ferritin

Low % Sat:
-low serum Fe with high TIBC

38

labs to check with ferritin

-ferritin is an acute phase protein elevated with inflammation
-need to also check ESR or CRP for accurate interpretation

39

Iron is a potent pro-

oxidant

40

large doses of supplemental iron interfere with absorption of

zinc and copper

41

hereditary hemochromatosis

-defect in hepcidin
-excessive Fe absorption
-accumulated Fe damages liver and increases risk of HCC

42

medicinal FE overdose

-hemorrhagic gastroenteritis
-shock and acidosis
coag defects
-hepatic failure

43

lethal Fe dose in children

1-2grams

44

especially critical during periods of growth and cellular/ tissue proliferation & immune function

zinc

45

sources of zinc

animal products (oysters)
beef> poultry> fish/milk/ eggs

46

zinc absorption is impaired by

phytate, a dietary complex involved in iron absorption

found only in plants,~corn, legumes, nuts

47

Zinc Absorption:
Systemic levels

unlike iron absorption, since absorption is not increased with deficiency

48

zinc homeostasis maintained by what paired processes

absorption and excretion
-zinc secreted into go tract with digestion as part of pancreatic-biliary secretions
-some is reabsorbed and some is excreted

49

how is zinc homeostasis different from iron

there is a route to excrete zinc, whereas with iron the body has to be careful how much iron to take in because it can be toxic and is difficult to get rid of

50

7 populations at risk for iron deficiency

- infants > 6 mths: low stores & high requirement
-premature infants: low stores & high requirement
-adolescents: high requirement & poor intake
-pregnant women: increased requirement (27mg/day)
-chronic infestations
-bariatric surgery
-elderly

51

9 populations at risk for zinc deficiency

-infants
- young children
-breastfed infants >6mths
-pregnant women
- monotonous plant diets: esp high in phytate
-bariatric surgery
-elderly
- GI illness/ injury: diarrhea
- Wounds, burns

52

why are breastfed infants > 6mths at risk for zinc deficiency?

after 6mths because human milk has low Zn levels after 6mths

53

contrast risk populations iron (2) deficiency vs zinc deficiency (4)

Iron:
-adolescents
-Chronic infestations

Zinc:
-breastfed infants >6mths
-monotonous plant diets: esp high in phyla
-Diarrhea
-Wounds/ burns

54

poor zinc status in the elderly is associated with a higher risk of what?

pneuonia

55

Copper ot zinc ratio (CuZ)

increased ratio in the elderly associated with higher mortality, may be a biomarker of aging

56

Zinc deficiency and death

worldwide
-estimated to account for 0.4 million deaths/ year in children younger than 5

(second only to vitamin A which is estimated to be responsible for 0.6 million deaths/ year)

57

acrodermatitis enteropathica

-mutation in zinc transporter ZIP4
-fatal if not treated
-responds to high doses of Zn supplements (lifetime)

58

acrodermatitis enteropathica presentation

severe dermatitis, growth failure, diarrhea

59

zinc toxicity

-relatively low
- >50mg/d can decrease HDL, impair absorption of Fe and Cu, cause nausea, diarrhea

60

zinc within first 24hours of symptoms of a cold

-decrease duration of illness by 1-4 days
-reduce severity of symptoms
-may prevent viral replication or attachment to nasal membranes

61

iodine sources

-seafood
-grown things: depends on content of soil- especially low in mountainous areas
-Today: iodized salt

62

cassava

-goitrogen
-contains ions that compete with iodide (like SCN-)
-associated with widespread goiter and hypothyroidism

63

Absorption process iodine

Iodide Uptake --> binding to T3, T4 --> Circulation

64

iodine worldwide deficiency

common--> endemic goiter and cretinism in children (5.7 million cretins exist; 1 billion persons at risk for I deficiency disorders)

65

Cretin child: deaf mutism

-dwarfed, mentally retarded, dull facies, large tongue

-I deficiency during pregnancy

66

I deficiency on fetus

-increased abortions, stillbirths, congenital abnormalities

67

goiter

-enlarged thyroid gland to compensate for decreased I for thyroid hormone synthesis

68

populations with endemic iodine deficiency

mean IQ loss: 13.5 points

69

Copper food source

shellfish, meats, nuts
low in milk

70

Copper absorption and metabolism

30-40% absorption from mixed diet, stored in liver, excreted in bile

71

Selenium

foods associated with with amino acids

72

keshan disease

-cardiomyopathy in china prevented with Se supplementation

Cause:
-interaction with other nutritional deficits or viral infection

*Viral mutation increases virulence in Se deficient host

73

selenium absorption and metabolism

-60-80% absorbed from diet
-Kidneys main site of homeostasis
-urine excretion