Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Clinical Chemistry > Vitamins > Flashcards

Vitamins Flashcards

1
Q

Fat soluble vitamins

A

Vitamins A, D, E, K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Water Soluble Vitamins

A

Vitamins C, B1, B2, B6, B12, folate, biotin, pantothenic acid
niacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Vitamin A function

A

fat soluble vitamin
binds to cell nuclear receptors
provitamin A (carotene) - structure equivalent of 2 vitamin A molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

processing of Vitamin A

A

Beta-carotene into retinal & then to retinol (active form) & retinoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

transport for Vitamin A

A

retinal binding protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

active form of vitamin A

A

retinol (OH group on the end)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

toxic level of vitamin A

A

anything over 100 ug/dl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

importance of vitamin A

A

growth, reproduction, immune system
cell differentiation - maintains epithelial integrity
vision- part of rhodopsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Vitamin A role in vision

A

retinol is oxidized in rods of eye retina to retinal
the complexed w/ opsin to form Rhodopsin
sight in dim light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Vitamin A deficiency

A 
lead to night-blindness- seen in malabsorption, liver impairment, premature infant
loss of hair
joint pain
headaches
drowsiness
vomiting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hypervitaminosis A

A

vitamin A toxicity > 140 ug/dl in plasma

measured by HPLC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Vitamin E

A

(alpha-tocopherol); anti-oxidant - primary defense against oxidation of unsaturated lipids & cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vitamin E metabolism

A

40% absorbed from GI, attaches to chylomicrons for transport to liver
then transported via VLDL to cells
excreted through feces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

deficiency of vitamin E

A

shows hemolytic anemia
can see in premature infants, fat malabsorption in adults
measured by HPLC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vitamin K function

A

(napthoquinone); essential for coagulation factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Vitamin K dependent coagulation factors

A

II, VII, IX, X also protein C & S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

source of vitamin K

A

50% diet & 50% gut bacteria

absorbed into body via bile salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

lack of vitamin K

A

leads to hemorrhagic crisis

usually related to GI malabsorption & antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

testing for vitamin K

A

use Prothrombin time (PT) -extended time

liver disease will also show low coag proteins but may not be vit K related

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

vitamin K toxicity

A

usually not seen in adults
children with vit K supplement at birth can see increase in bilirbuin
supplements rich in vit K : garlic, gingko, & ginseing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Vitamin D function

A 
1,25 DHCC
facilitates calcium (& phosphorus) absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

D2

A

ergocalciferol - not naturally occurring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

D3

A

cholecalciferol

can make from sunshine on 7-dehydro-cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

vitamin D absorption

A

absorb from gut; attaches to chylomicrons for transport to liver
stored in liver
excreted in bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
vitamin D stimulates
ca2+ absorption along w/ phosphorus from intestine w/ PTH- increases mobilization of ca2+ from bone to circulation has apoptotic effect - cancerous cells/ loses growth regulation
26
vitamin D deficiencies
children- ricketts osteomalacia- softening of the bone AED- hinder vit D absorption any malabsorption condition or renal issue
27
vitamin D toxicity
``` children hyperparathryoidism hypophosphatemia pregnancy excess vitD leading to excess calcium deposits in heart & kidneys (damage can be irreversible) ```
28
laboratory testing for vitamin D
calcium testing - PTH, serum Ca2+, urine Ca2+ | assay 25-OH-cholecalciferol or 25-OH vit D3 by immunassay or HPLC
29
vitamin B1 (thiamine)
used to make thiamine pyrophosphate TPP - important coenzyme | needed for decarboxylase subunits of dehydrogenase complexes
30
vitamin B1 metabolism
absorbed through GI | excreted through the kidney; out the urine
31
chronic deficiency of vitamin B1
beri beri -wet & dry | seen in underdeveloped countries & alcoholics
32
lab assays for vitamin B1
looks at RBC transketolase enzyme activity or ETK before & after thiamine pyrophosphate addition (TPP) if see >25% increase in ETK after adding TPP, then patient is thiamine deficient
33
vitamin B2 (riboflavin)
used to make flavin mononucleotide or FMN & flavin adenine dinucleotide or FAD coenzymes used in oxidation-reduction reactions (krebs cycle)
34
vitamin B2 absorption
absorbed from GI small intestine stored for 5 months in healthy person excreted through kidney
35
vitamin B2 toxicity
no known toxicity
36
vitamin B2 deficiency
seen in alcoholics, chronic diarrhea, malabsorption, drugs: phenothiazine, oral BCP, TCAs redness & sores
37
lab assays for vitamin B2
when glutathione reductase activity is decreased by 40% this indicates riboflavin (b2) deficiency
38
vitamin B6 forms
pyridoxine (plant source) pyridox-amine pyridoxal (animal sources) all get converted to PYRIDOXAL-5'-PHOSPHATE
39
vitamin b6 absorption
absorbed through the GI tract & excreted through the urine
40
vitamin b6 function
used for synthesis, catabolism, & interconversion of amino acids reactions for metabolism of proteins, lipids, & CHOs COENZYME FOR AST & ALT!!!
41
lab measure for vitamin b6
measures function changes to protein | often looks at homocysteine (!!) in blood & urine
42
vitamin b6 deficiency
``` usually not alone - other b complex vitamins also deficient uremic patients (elevated BUN), liver disease,malabsorption, malignancies, alcoholics associated w/ hyperhomocysteinemia ```
43
vitamin b6 associated anemia
see normo, micro | SIDEROBLASTIC ANEMIA
44
niacin source
made from tryptophan as well as dietary intake | hard to be deficient in niacin
45
niacin function
combination of nicotinic acid & nicotinamide ; both needed to make NAD & NADP need these coenzymes for respiration, lipid metabolism, fatty acid metabolism, & glycolysis
46
lab measure of niacin
measure NAD & NADP (end products of niacin)
47
niacin absorption
absorbed via GI & small intestine | metabolized form out the urine
48
niacin deficiency
not usually seen Pellagra (4Ds) & alcoholics 4Ds= diarrhea, dementia, dermatitis, death
49
niacin toxicity
very low, excess niacin leads to decreased lipids, increased flushing, & blood vessel vasodilation
50
Folic acid/folate function
necessary for 1-carbon transfers | increased folate needs in pregnancy - helps reduce neural tube defect
51
folic acid/folate absorption
closely linked to vit b12 folate absorbed in jejunum w/ intrinsic factor excess excreted through kidney & out feces large amount of folate made by colon bacteria & absorbed
52
folate deficiency
MEGALOBLASTIC ANEMIA alcoholism, malabsorption, carcinoma, chronic hemodialysis, hemolytic & sideroblastic anemia drugs: sulfasalazine, isoniazid, cycloserine, phenytoin, alcohol, oral BCP, methotrexate
53
lab analysis of folate
look at serum folate & RBC folate (RBC folate tells about folate stores) look for increase in serum homocysteine as indicator for folate deficiency
54
vitamin b12 (cobalamin) absorption
absorbed from ileum using INTRINSIC FACTOR from stomach, absorbed through mucosal cells, released, bound to new transport protein, goes into plasma to be taken to liver, BM, or tissues for deposit
55
vitamin b12 carrier protein
``` needs a carrier protein bc it is so large even though it is water soluble transcobalamin hydroxycobalamin methyl cobalamin deoxyadenosyl-cobalamin ```
56
vitamin b12 function
coenzyme in reactions for hematopoiesis & fatty acid metabolism
57
active form of vit b12
methyl cobalamin & dexoyadenosyl-cobalamin
58
vit b12 deficiency
``` increases w/ age PERNICIOUS ANEMIA vegans FISH TAPE WORM (D. lateum) malabsorption antibody to vit b12 -IF complex ```
59
vit b12 toxicity
none known, stays in liver for a decent amount of time (days-months)
60
lab test for vit b12
Schilling's test- radioactive b12 measure serum & urine for radio b12 micro test w/ Lactobacillus leischmanii immunoassay for vit b12
61
Biotin function
``` role in gluconeogenesis, lipogenesis, fatty acid synthesis role in # of carboxylation reactions: pyruvate decarboxylasse acetyl CoA carboxylase etc etc ```
62
biotin absorption
absorbed from small intestine & synthesized by gut bacteria (!)
63
lab assay for biotin
chemilumenescent or spectrophotometric methods
64
biotin deficiencies
affect the enzymes leading to adverse effects on the skin, pallor, mood & GI depression & vomiting
65
biotin toxicity
not seen
66
pantothenic acid
converted to 4'-phosphopantotheinyl moiety which is covalently bound to either serum actyl carrier protein or coenzyme A
67
pantothenic acid source
found in many foods making deficiencies extremely rare
68
pantothenic acid deficiency
rare - see irritability, constipation, numbness, anorexia, tingling in hands & feet
69
pantothenic acid toxicity
not seen
70
pantothenic acid lab analysis
lactobacillus plantarium Pediococcus acidilactici RIA, GC, HPLC give PA load & look for metabolite: acetylated-p-aminobenzoic acid in urine
71
vitamin C (ascorbic acid) function
strong reducing agent(!!) important for hydroxylation reactions of proline & lysine to cross link (COLLAGEN SYNTHESIS) & for the conversion of tyrosine to catecholamines (!!!)
72
vitamin C deficiency
'scurvy'/ limey's disease | hemorrhagic tissues - bleeding gums, impaired wound healing & anemia
73
vitamin C absorption
absorbed through GI, distributes in water, excreted via urine NOT STORED IN BODY
74
lab assays for vitamin C
colorimetric method | HPLC- newer

Clinical Chemistry (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions