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Flashcards in MCP 5 Deck (34):
0

how do vitamin deficiencies arise?

poor nutrition, increased demand, problem with absorption of one or more vitamins, interactions with medications

1

lipid soluble vitamins

A, D, K, and E. structure resembles lipids. generally are stored more efficiently than water soluble. deficiencies dont arise as quickly. toxicity may be a problem, especially with D and A.

2

water soluble vitamins

B and C. more hydrophillic structure. in general, deficiencies can arise more rapidly if vitamin is unavailable since they are excreted efficiently. less likely to be toxic

3

vitamin A functions

visual cycle: rhodopsin and cone opsins. synth of certain glycoproteins and mucopolysaccharides. retinoic acid: acts as a hormone. antioxidant

4

vitamin A deficiency

night blindness early, xerophtalmia (thickening of conjunctiva) advanced. follicular hyperkeratosis (goosebumps that dont go away). anemia despite normal iron intake. poor growth in children. increased suceptibility to infection and cancer. susceptible groups are poor, malnourished, and premature babies

5

vitamin A toxicity

accumulates in liver. excess intake can be toxic. symptoms include nausea, diarrhea, bone pain, scaly skin, and orange cast to skin.

6

vitamin D functions

maintaining bone. calcium homeostasis. acts as a hormone: receptors are present in many tissues but full range of activity is unknown

7

vitamin D deficiency

rickets in children, osteomalacia in adults. increased susceptibility to breast and other canceres, metabolic syndrome/diabetes, and infection. susceptible groups are poor, elderly, alcoholics

8

synth of active vitamin D

needs three organ systems: skin (sunlight), liver, and kidney (both hydroxylation)

active form is called calcitriol

9

vitamin D and cancer

low serum vitamin D in post menopausal women is correlated with increased risk of breast cancer. polymorphisms of D receptor and breastcancer links have been amde. D effects are postulated to arise from cell cycle signalling effects through the D receptor

10

vitamin K functions

localization of enzymes required during blood clotting. helps catalyze addition of gamma-carboxyglutamate to clotting enzymes.

11

vitamin K deficiency

results in easy bruising, bleeding, and hemorrhage. susceptible groups are newborn infants, patients on long term antibiotics, elderly and other with defects in fat absorption. babies lack bacteria that make vitamin K and deficiency can lead to brain bleed. given shot at birth. In adults, long term antibiotics can kill the bacteria that make K.

12

vitamin K in blood clotting

essential for enzymes involved in GLA modification of several clotting enzymes

13

vitamin E function

antioxidant. scavenges free radicals. protects membranes from damage. prevents oxidation of LDL

14

vitamin E deficiency

cardiovascular disease. neurological symptoms. susceptible groups include patients with severe, prolonged defects in absorption (celiac) or genetic effects

15

vitamin C function

cofactor for oxidases involved in collagen formation. required for synthesis of steroids in stress response. aids in absorption of iron. has antioxidant activity.

16

vitamin C deficiency

mild: bruising, immunocompromise
severe: scurvy (decreased would healing, osteoporosis, hemorrhage and anemia, fatigue, corkscrew hairs, pinpoint hemorrhages, periodontal disease)

susceptible groups: people with poor diet, smokers, pirates

17

energy releasing B complex vitamins

thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6)

18

hematopoietic B complex vitamins

Folate (B9) and Cobalamin (B12)

19

energy releasing B vitamin deficiencies

symptoms show up first in rapidly growing tissue: skin (dermatitis, red tongue, swollen, glossitis), GI (diarrhea)

nervous system affected due to high energy demand. peripheral neuropathy or tingling of extremities, depression, confusion, lack of coordination, malaise.

20

thiamine function

vitamin B1. required cofactor for several enzymes in cellular energy metabolism. particularly critical in nervous system

21

thiamine deficiency

mild: GI symptoms, depression, fatigue.
moderate: Wernicke korsakoff syndrome
severe: beriberi

22

wenicke korsakoff syndrome

moderate/severe thiamine deficiency. seen in alcoholics. mental disturbance, unsteady gate, uncoordinated eye movements. occasionally congestive heart failure

23

beriberi

severe thiamine deficiency. seen in japan when they had polished rice. extreme muscle weakness, polyneuropathy, heart failure. wet beriberi has edema

24

riboflavin function

B2. precursoe of FAD and FMN, key coenzymes for redox reactions involved in energy metabolism.

25

riboflavin deficiency

ariboflavinosis: rash around nose, inflammation of mouth and tongue, burning and itchy eyes, light sensitivity. susceptible groups are alcoholics, deficiency is quite uncommon

26

niacin function

B3. precursor of NAD and NADP. coenzymes important in redox reactions of energy metabolism. given to patients with hypercholesterolemia or hypertriglyceridemia

27

niacin deficiency

B3. pellagra, characterized by dermatitis, diarrhea, and mental symptoms (confusion, memory loss, mania)

susceptible groups are those with corn or millet based diets

28

biotin function

coenzyme for several carboxylases

29

biotin deficiency

rare, but can be caused by eating a lot of raw eggs. eggs contain avidin which binds biotin very tightly, causing it to not function

30

pantothenic acid function

B5. required for synth of CoA. CoA is a coenzyme for a ton of things. required for TCA cycle and metabolism of all fats and proteins

31

pantothenic acid deficiency

B5. very rare. symptoms are typical of B vitamins. B5 is found in a ton of foods so the deficiency is rare

32

pyridoxine function

precursor of pyridoxal phosphate. required for glycogen breakdown and synthesis of GABA and heme.

33

pyridoxine deficiency

B6. mild: irritability, nervousness, depression. Severe: peripheral neuropathy, convulsions, decreased glucose tolerance, hyperhomocysteinemia (cardiovascular risk), anemia

susceptible groups are patients treated with certain drugs : isoniazid for TB