vitamins Flashcards

1
Q

vitamins are essential for —– , they —- be synthesised in the body , they are —- , need to be — to prevent disorders of metabolism
vitamins fall into 2 groups which are:

A
  • normal metabolism
  • cant be synthesised
  • micro nutrients ( bc we need to consume them in micro grams )
  • ingested
  • fat soluble as: A,D,E,K
    -water soluble as: b group and C
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2
Q

vitamins fall into 2 groups :
1. fat soluble which includes:
2. water soluble which is broken down into —- and —– by which this is broken down into :

A
  • vitamin a –> retinoids
  • vitamin d —> calcitriol
  • vitamin e —> tocopherol
  • vitamin k —> phylloquinone and menaquiones
    2. water soluble broken down into :
  • non-b complex which is vitamin c –> ascorbic acid
  • b- complex which is broken down into:
    1- energy releasing
  • thiamin b1
  • riboflavin b2
  • niacin b3
  • panothetic acid b5
  • biotin b7
    2- heamotopoietic
  • folic acid b9
  • cobalamin b12
    3- other: pyroxidine b6
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3
Q

dietary sources of fat soluble vitamins:
- vitamin A aka retinoids can be taken from:
1- animal sources in form of —-
2- plant sources in from of —–
we can get it from —-
- we get vitamin d from:
- we get vitamin k1 from:
- we get vitamin k2 from:
- we get vitamin e from:
- we get vitamin b complex from:
- vitamin c :

A
  • retinyl esters ( REs)
  • beta carotene ( pro vitamin A )
  • sources : red meat , carrots , eggs , milk/diary , green , catantloupe , ( any orange coloured)
  • sun , fortified milk
  • green veggies
  • gut microflora in large intestine
  • seeds nuts oil and oily fish as salmon
  • fish milk eggs broccoli
  • fruits as cantaloupe , strawberries , oranges , kiwi
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4
Q

in vitamin a :
retinol, retinal , retinoic acid m and b carotene are —-

A

biochemical isoforms

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5
Q

in vitamin a:
retinol , retinal , retonoic acid are —

A

active forms

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6
Q

vitamin a fucntions are: ( think of eyes and immune system )
1- essential for —-
2- promotion of —-
3- differentiation and maintenance of —- cells
4- gene —-
5- maintenance of —-
vitamin a deficiency leads to:
symtoms :
toxicity:

A
  • vision
  • growth
  • epithelial
  • gene expression
  • reproduction
  • infertility, night blindnessm retardation of growth , xerophthalmia , impairment of immune system , dermatological skin problems
  • symptoms: dryness of eyes m bitots spot
  • yes , excess can lead to hypervitamintosis
  • excess vitamin can increase fractures
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7
Q

true or false:
excess vitamin a can increase fractures and cause hypervitaminosis

A

true

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8
Q

vitamin d:
- cholecalciferol and ergocalciferol are the —–
- 1,25 dihydroxy vitamin d3 - calcitriol are the —–

A
  • biochemical isoforms ( no need to remember these names)
  • active forms ( need to know these)
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9
Q

vitamin d is responsible for the regulation of — uptake in the body
deficiency includes:
symptoms :
toxicity:

A
  • calcium
  • rickets in children and osteomalacia in adults
  • soft pliable bones bow shaped legs
  • yes to toxicity
  • application of sunscreen or presence of dark skin color decreases its sythesis
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10
Q

alpha tocopherol is the – of vitamin e and the deratives of tocopherol is the — form
fucntios include:
the deificnecy:
symptoms:

A
  • biochemical isoforms
  • active form
  • anti oxidant , protects polyunstarutaed fatty acids PUFA from peroscidation
  • rare but can happen
  • rbc fragility leads to hemaolytic anemia , skletal pain
    ( note: benefit of supplementation not established in trails )
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11
Q

biochemical and active forms of vitamin k are:
fucntion:
deficiency:
symptoms :
toxicity:

A
  • menaquinone and phylloquinone
  • major role in coagulation cascade and acts as a cofactor
    -occurs in new born haemorrhage disease of new born , rare in adults
  • bleeding
  • rare
  • produced by intestinal bacteria
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12
Q

absorption of fat soluble vitamins:
1.—- and — function needs to be intact for absorption
2. the fat soluble vitamins are cleaved from — proteins by — enzymes in —–
3. —- solubilises them for absoprtion into micelles and chylocomicrons
4- transported to the — for storage via —-

A
  • pancreatic and biliary
  • carrier
  • pancreatic
  • small intestine
  • bile salts
  • liver
  • lymph system
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13
Q

hypervitaminosis :

A

vitamin d:
Exceed 10X RDA
(UL = 50mg/day)
Hypercalcaemia:
Ca deposits in tissues, joints,
lungs, brain, kidney (renal calculi)
Muscle weakness
vitamin a:
RDA: 700mcg/day for female;
900mcg/day for male. UL= 3000mcg/day
Acute: vomiting, vertigo, blurry vision
Chronic: hyperlipidemia, hepatotoxicity
bone and muscle pain, visual impairments
Teratogenic: Spontaneous loss of fetus; Fetal
malformations
vitamin e:
RDA= 15mg; Exceed >1000 mg α-tocopherol daily
Fatigue, headache, diarrhoea, blurred vision
Impaired blood coagulation

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14
Q

biochemical isoform of vitamin b1 is —- and the active form is —-
function:
deficiency leads to:
toxicity:
symptoms:

A
  • thiamine
  • thiamine prophosphate
  • involved in the conversion of
    pyruvate to acetyl CoA: glycolysis into the citric acid cycle, branched-chain amino acid oxidation
    -Beriberi; Wernicke-
    Korsakoff syndrome (common in indiviuals w high dependency of alcohol )
  • none
  • tachycardia, vomiting,
    convulsion, apathy, loss of eye movements, loss of memory
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15
Q

vitamin b3:
- biochemical isoform:
- active form :
-function:
- deficiency leads to:
- smptoms:
- toxicity:

A
  • niacin
  • Form the coenzymes nicotinamide
    adenine dinucleotide (NAD+) and nicotinamide
    adenine dinucleotide phosphate (NADP)
  • electron transfer
  • Pellagra, known as the 3D
    disease
    -Diarrhoea, Dermatitis (photosensitive),
    Dementia and (Death)
  • none
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16
Q

true or false:
low doses of niacin used to treat hyperlipedemia

A

false , high doses

17
Q

vitamin b2:
- biochemical isoform:
- active form:
- function:
- deficiency:
- symptoms:
- toxicity:

A
  • riboflavin
  • A constituent of flavin mononucleotide (FMN) and
    flavin adenine dinucleotide (FAD)
  • electron transfer
  • abrioflavinosis ( not common )
  • Inflammation of the lips, cracking of skin at the corner of the mouth: angular stomatitis, dermatitis,
    vascularisation of the cornea
  • none
18
Q

vitamin b5:
- biochemical isoform and active form:
- function:
- deficiency:
- symptoms:
- toxicity:

A
  • pentathenic acid
  • Required for the synthesis of
    coenzyme A (CoA), also as an acyl
    carrier (Acyl: C=O-R)
  • rare but can occur
  • Numbness, tingling of
    hands and feet, vomiting and fatigue
  • none
19
Q

vitamin b6:
- biochemical isoform:
- active form;
- function:
- deficiency:
- symtoms:
- toxic:

A
  • pyridoxine
  • Pyridoxal 5’ phosphate (PLP),
    pyridoxamine 5’ phosphate (PMP)
    -Co-enzyme for enzymes, particularly in amino acid metabolism
  • rare but can happen
  • Glossitis, neuropathy, microcytic
    hypochromic anaemia
  • yes
    ( sensory neuropathy occurs at high doses )
20
Q

vitamin b7:
- biochemical isoform:
- active form:
- function:
- deficincy:
- toxicity:

A
  • biotine
  • enzyme bound biotin
  • attaches to active site of carboxylate
  • rare but can happen
  • A scaly red rash around the eyes,
    nose, mouth (‘biotin deficient face’) and
    genital area; depression, neuropathy
  • none
    ( note: Consumption of large amounts of egg white (contains a protein called avidin, that has a high affinity for biotin) can induce a deficiency)
21
Q

vitamin b12:
- biochemical form:
- active form:
- function:
- deficiency results from:
- deficiency leads to:
- symptoms:
- toxic:

A
  • cobalamin
    -Methylcobalamin, deoxyadenoyslcobalamin
  • Biological methylation reactions:
    homocysteine to methionine; synthesis of succinyl-CoA
  • pernicious anemia
  • dementia and spinal degeneration
  • higher than normal levels of homocysteine, megaloblastic anemia
  • none
    ( note: needs to bind to intrinsic factor to be absorbed in the gut, malabsorption in the gut can lead to a deficiency)
22
Q

vitamin b9:
- biochemical isoforms:
- active form:
- function:
- deficiency leads to:
- symtoms:
- toxic:

A
  • folic acid , folate
  • tetrahydrofolic acid
  • Coenzymes in single carbon transfer
    reactions, biological methylation reactions, synthesis of methionine from homocysteine, purines and thymidine monophosphate
  • megaloblastic anemia and neutral tube defects
  • Anaemia, higher than normal levels
    of plasma homocysteine, low birth weight
  • none
    ( note: Administration of high levels of folic acid can mask vitamin B12 deficiency)
23
Q

vitamin c:
- biochemical isoform:
- active form:
- function:
- deficiency leads to:
- symptoms:
- toxixty:

A
  • ascorbic acid
  • ascorbic acid
  • Anti-oxidant, co-enzyme for
    hydroxylation reactions e.g. synthesis of collagen
  • scurvy due to impaired collagen synthesis
  • Sore spongy gums, loose teeth,
    poor wound healing
  • yes at risk of calcium oxalate stones
    ( note: benefits of supplementation is not established in trials)