Micronutrients II - Vitamins Flashcards Preview

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Flashcards in Micronutrients II - Vitamins Deck (93)
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Vitamins

typically cofactors for enzymes
organic compounds required for diet in only small amounts to maintain fundamental cell functions
not catabolized
Organic

1

Which vitamins are most utilized in energy metabolism?

B vitamins

2

how many water soluble vitamins?

9

3

how many lipid soluble vitamins?

4

4

Vitamin-like compounds

Inositol
Choline
Lipoic Acid
PQQ-Pyrroloquinoline quinone

5

Inositol

phospholipids

6

Choline

in phospholipids, methyl donor
choline free diet could lead to liver damage

7

Lipoic Acid

not a vitamin but required for pyruvate decarboxylase
animals can make this

8

PQQ-pyrroloquinoline quinone

methoxatin
redox cofactor for quinoproteins
ex: flavoproteins - dehydrogenases

9

Vitamin D only needed when

sunlight is absent

10

Primary deficiency

lack of adequate intake in diet

11

causes of Primary deficiency

poor nutrition/food habits, poverty, ignorance of nutrition needs, insufficient food, lack of proper vitamin rich foods, food fads, food taboos, vitamin destruction, anorexia

12

Secondary deficiency

poor availability or utilization of a vitamin due to environmental or physiological conditions

13

Causes of secondary deficiency

poor digestions (achlorhydria-low gastric acid)
malabsorption (diarrhea, infections)
impaired utilization (drug therapy)

14

Vitamin deficiencies significant in

any pt with digestion/malabsorption problems
chronic substance abuse (alcohol) bad diet & inhibits uptake of vit
recent surgery, total parenteral nutrition
elderly, pregnant/breastfeeding, smokers, alcoholics, diabetics
risk thiamine deficiency with high CHO diet

15

What aids in fat soluble vitamin absorption?

Bile

16

digestive enzymes from pancreas help uptake

vitamin K

17

Bacteria in the gut make small amount of

vitamin K, B12, and biotin

18

Fat soluble vitamins are absorbed with

dietary fat

19

where are fat soluble vitamins stored?

liver and nonspecifically adipose tissue

20

Risk of toxicity with what vitamin?

B vitamins

21

Vitamin A

mixture of Retinoids
role in gene regulation - reproduction, embryogenesis, development, cell differentiation and proliferation) vision, maintenance of brain function and skin

22

Vitamin A deficiency

night blindness
hyperkeratosis

23

Vitamin A Excess

birth defects, (tetratogenic), blurred vision, liver damage
Osteoporosis, hypercalcemia

24

Vitamin A is derived from

carotenoids
plant pigments
b-carotene
-three forms - alcohol, aldehyde and acid

25

Find Vitamin A in

green, leafy vegetables
colored veggies
organ meat - liver

26

Why is beta carotene a safer source?

conversion to Vit A in gut decreases as dose increases
Absorption depends on type of food and how much fat is also in diet

27

How is Vitamin A taken up?

Retinol and carotenoids bound in enterocyte to Carotene binding proteins
carried in blood by chylomicrons or albumin

28

How is vitamin A important for vision?

combines with opsin to form rhodoposin in rod and cone cells
impt for the shape and structure of the conjunctiva and the cornea as well
functions in cellular differentiation - RXR and RAR receptors

29

Xerophthalmia

damage to cornea
can occur with vitamin A deficiency