vitamins

Question 1

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:

Answer 1

• 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

Question 2

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 :

Answer 2

• 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

Question 3

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 :

Answer 3

• 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

Question 4

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

Answer 4

biochemical isoforms

Question 5

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

Answer 5

active forms

Question 6

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:

Answer 6

• 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

Question 7

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

Answer 7

true

Question 8

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

Answer 8

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

Question 9

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

Answer 9

• 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

Question 10

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

Answer 10

• 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 )

Question 11

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

Answer 11

• 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

Question 12

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 —-

Answer 12

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

Question 13

hypervitaminosis :

Answer 13

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

Question 14

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

Answer 14

• 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

Question 15

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

Answer 15

• 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

Question 16

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

Answer 16

false , high doses

Question 17

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

Answer 17

• 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

Question 18

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

Answer 18

• 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

Question 19

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

Answer 19

• 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 )

Question 20

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

Answer 20

• 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)

Question 21

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

Answer 21

• 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)

Question 22

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

Answer 22

• 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)

Question 23

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

Answer 23

• 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)