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
what part does vit c specifically play in making collagen more stable
- hydroxylase enzymes needs Fe2+
- vit c = antioxidant
- prevents Fe2+ -> Fe3+
which tissues are particularly affected by lack of Vit c?
ones with rapid turnover
PDL
why do we want hydroxyproline/ hydroxylysine?
- better h bonding
- more stable triple helicose structure
- if not collagen-> easily broken up
-> collagen will form fragile tissue
What are the Oral Symptoms of Vit C Deficiency?
initial = gingival inflam
progressive = impaired collagen synthesis
What can Reduce the effect of ascorbic acid?
sodium ascorbate
daily chewable vit c ascorbic acid can cause harm- how?
ph 2.8
causes erosion
buffering into ascorbate salt with sodium buffers it
what is vit b complex?
all vitamin bs can be found from same foods
9 of them
interact with each other
one deficiency can lead to/ be an indication of deficiency of another
function of b1 b2 b3 b8
different aspects of energy production
function of b6
amino acid regulation
hormone regulation
symptoms of vit b deficiency:
depends on which vit b you lack
- fatigue
- confusion
- anaemia
- compromised immune system
- skin rashes
groups at risk of deficiency of vit b complex
1) elderly
2) pregnant women
3) conditions that cause malabsorption
e.g. Crohns, Celiac, HIV + alcohol abuse
Sources of B9
green leafy veg
animal livers (where it has been stored)
nuts
whole grain cereals
Function of B9 (3)
1) biochemical reactions involved in DNA synthesis
2) needed for cell division
3) has a role in nucleic acid synthesis in rapidly growing cells:
foetus, bone marrow (producing RBCs), hair follicles, mucosal cells, cancer cells
what random cool thing can b9 do?
get rid of homocysteine
reduces risk of heart disease
- lowers risk of baby having cleft lip
What does Deficiency of B9 Lead to?
megaloblastic anaemia hair loss
fatigue
heart disease
birth defects!
- spina bifida- CONGENITAL and anencephaly
- neural tube doesn’t close during pregnancy at 28 days = spine is open
not enough b9= cells dont grow as fast as they are supposed to be
What are the Oral Symptoms of Vit B9 Deficiency
during pregnancy, cleft lips risk are high
what does chemotherapy with METHOTREXATE do?
replicates symptoms of B9 deficiency
prevents folic acid from reaching active form
causes
hair loss
loss of appetite
weakness
sickness
Where is B12 Stored?
liver
healthy adult stores enough to last 1 year
sources of B12
we can’t make it:
meat
eggs
dairy
wholegrains
Function of b12 (4)
1) required for FOLATE metabolism
2) maintain low homocysteine level (protects heart)
3) involved in blood formation
4) crucial for nerve functioning (forms myelin sheath around nerves)
symptoms of deficiency of vit b complex:
damages rapidly growing cells
skin, hair follicles, mucosa, growing foetus cells, cancer cells
cant dna synthesise properly
How is B12 (cobalamin) absorbed and transported?
ABSORPTION:
- B12 binds to glycoprotein (intrinsic factor) in stomach
= vitamin-intrinsic factor
VIF complex recognises surface receptors of mucosal cells in ileum
can be absorbed into blood stream
TRANSPORT + STORAGE:
- complex is transported bound to a B12 binding protein (transcoblamin)
-> gets stored in the liver
When is a Deficiency of B12 caused?
insufficient intrinsic factors
gastritis/ ulcers/ beriatric surgery can cause deficiency
What does a deficiency of B12 lead to?
damage to growing cells
neurological symptoms
fatigue
chronic pain
infertility
blood disorders
Which groups are at risk of vit B12 Deficiency? (4)
1) strict vegetarians (need to take supplements)
2) elderly- reduced diet intake
3) people who have malabsorption as side effects of medication
e.g. diabetes, renal insufficiency + dementia
4) people w malabsorption diseases (gastritis- cant synthesise intrinsic factors)
Why is it Hard to Detect B12 Deficiency
1)combined with folic acid deficiency
if folic acid deficiency gets treated, some symptoms like hair loss would disappear
but the neurological ones wouldn’t
2) blood tests dont differentiate between active form and non active form
How do you Detect b12 Deficiency
two step blood test
- determine holotranscobalamin content
- determine metabolic product concentration
1) calculates ALL b12 in blood (even with intrinsic factor missing)
2) calculating metabolites in blood which are there because of lack of b12 (methylmalonic acids and homocysteine)
- administer b12 through IV asap to prevent neurological damage
How is B12 Administered?
intravenously asap
Oral Symptoms of B12 Deficiency
glossitis
angular cheilitis
ulcers
high caries rate
gingival problems in children below 11
What Medications can Induce all of these Vitamins a Deficiency, what Diseases are they taken for?
Proton Pump Inhibitors
- Vitamin B12 and C
- gastroesophageal reflux disorder
Metformin
- Vit B12
- diabetes
Levodopa
- Vit B12
- Parkinson’s
symptoms of vit b deficiency:
depends on which vit b you lack
- fatigue
- confusion
- anaemia
- compromised immune system
- skin rashes
what does chemotherapy with METHOTREXATE do?
replicates symptoms of B9
what does chemotherapy with METHOTREXATE do?
replicates symptoms of B9
