Vitamins Flashcards
water soluble vitamins?
not stored in body
less likely to be toxic
excreted through urine
fat soluble vitamins?
stored in adipose/fat tissue
need to be transported by eating fats
transported out of these issues
TOXIC LEVELS!!
sources of vit D
egg yolk, fish oil and plants
What is the Precursor for Vitamin D
Ergosterol
What Does Excess Vit D cause?
nausea and muscle weakness
calcium absorption
bone resorption
What Does Deficiencies of Vit D cause in the Oral Cavity?
increase risk of caries and periodontal disease
enamel and dentine hypoplasia
How does Vit D Activate?
ergosterol converted to ergocalciferol
7-dehydrocholestrol converted to cholecalciferol
catalysed by 1,25-dihydroxyvitamin D3
is vitamin D water soluble?
no
is vit D fat-soluble and what happens to it in excess?
yes, stored in fat and adipose tissue
What happens to water-soluble vitamins in excess?
non-toxic and excreted in the urine
Give 3 water-soluble vitamins.
vitamin C
vitamin B9 (Folic Acid)
vitamin B12
2 Forms in which vit C exists.
Ascorbic Acid
Ascorbate Salts
Sources of Vit C
1) citrus fruits
2) MOST: veg (PEPPERS = ULTIMATE source)
role of vit c with iron absorption:
helps to convert the iron in plant foods
-> easily absorbing form by body
- need iron to producte hemoglobin in red blood cells
-> no iron= the body can become anaemic
(fatigue, weakness)
Vitamin C enhances absorption of Fe:
1) by reducing it to a more absorbable form 2) helping it pass through the intestinal wall into the bloodstream
consuming foods rich in vitamin C+ iron= increases the amount of iron that the body absorbs
What are 3 the Functions of Vit C
1) antioxidant - prevents Fe2+ into Fe3+
(scavenges free radicals + removes)
- produced by exposure to chemicals/ radiation-> cancer)
2) Collagen synthesis
ascorbic acid + collagen formation in lab
3) iron absorption- mild anaemia
why does lack of vit c cause scurvy?
1) impaired wound healing
2) fragility of capillaries
complete destruction of tooth attachment
-> collagen is in extracellular matrix of capillaries + provides structure/ support to capillaries
what is scurvy?
starts:
bleeding gums
later:
severe pd
looseness of teeth, tooth loss
What does vit c deficiency lead to?
scurvy
mild anaemia, damage to blood vessels
what is dysphagia?
inability to swallow
get at later stages of dementia
dont get all vits into soft food
Which Groups are at Risk of Vit C Deficiency? (6)
1) elderly- limited diet
2) alcohol/drug abuse - alcohol destroys enterocytes in intestine
causes vit deficiency -> malabsorptions
3) babies fed on cows milk- get vits from mum breast milk
4) smokers/ second hand smokers
5) FAD diets- protein shakes only, no vits
6) renal failure and dialysis- lose nutrients from damage to kidneys
7) malabsorption conditions- vits not absorbed in gut
if their gut mucous membrane is destroyed
direct link between vit c and smoking?
are deficient in vit c
need 2x as much vit c
smoking damages blood vessels
vits depleted completely into antioxidant function
getting rid of free radicals from smoking
structure of collagen
3 polypeptide chains
each chain has 3 amino acids:
glycine, proline, lysine
vit c needed for hydroxylation of proline/ lysine
NEED HYDROXYPROLINE/ HYDROXYLYSINE
collagen = fragile, easily broken up
-> weak, fragile tissue