Vitamins E lec Flashcards
why is vitamin k important
important in blood clotting and the formation of mineralised tissues
why are babies given vitamin k AT birth
to stop from internal bleeding
what is the RNI of vitamin K in the uk
no established RNI
what are our sources of vitamin K
from gut bacteria but also available in green veg and egg yolk and liver and cereals
why can we get vitamin K deficiency
lack of vitamin K
long term antibiotic use which can diminish gut bacteria
anticoagulant drugs such as warfarin- antagonists
new born babies have sterile gut so cannot make fit k
what is the function of vitamin k
essential in the formation of gamma carboxylgutammate
what happens when there is a deficiency of vitamin k
it cannot be used as co factor to produce gamma carboxyglutamate and therefore inhibits protein function
which clotting factors contain gamma carboxyglutamate
clotting factors II,VII,IX,X
What do clotting factors II,VII,IX,X have in common
they all contain gamma carboxyglutamate
what else is required for blood clotting
calcium ions
what will too much warfarin cause
uncontrollable haemorrhage
what is warfarin used as
rat poison
how do we treat warfarin poisoning
vitamin K injection
which protein is involved in bone formation and contains gamma carboxyglutamate
osteocalcin
what does osteocalcin contain
contains gamma carboxyglutamate
what are infants who are born to mothers taking warfarin at risk of
foetal warfarin syndrome- severe bone deformities
what is another name for vitamin A
retinol
what is the RNI for vitamin A in women
600mg/day
what is the RNI for vitamin A in men
700mg/day
what are some sources of vitamin A
butter whole milk egg yolk liver fit oils
what does XS vitamin a lead to
toxic
skin and nerve disorders
also teratogenic( causes congenital foetal malformation)
what are the three active forms of vitamin A
RETINAL
RETINOIC ACID
B carotene
describe retinal
binds to opsin to fome the visual pigment rhodopsin which helps us see in low level light
describe retinoic acid
acts as as steroid hormone increasing the transcription of proteins controlling cell growth and differentiation
describe b carotene
an antioxidant- protects dan against oxidative damage which may cause cancer
what can deficiencies of vitamins a present as
mild- follicular hyperkeratosis
anemia and increased susceptibility to infection and night blindness
what can severe vitamin A deficiency present as
progressive keratinisation of the cornea of the eye leading to xerophthalmia- infection sets in leading to haemorrhaging and permanent loss of vision
what are the oral implications of vitamin a deficiency
impaired healing
desquamination of oral mucosa and keratosis
gingival hypertrophy loss of taste disturbed enamel and dentine formation
what is another name for vitamin b1
thiamin
what is the recommended nutrient intake for thiamin in men
1mg/day
what is the recommended nutrient intake for thiamin in women
0.8mg/day
what are some sources of thiamin
whole grains pork yeast dairy and legumes
what is the function of thiamin
coenzyme in dehydrogenase enzymes involved catabolism
also important in the conduction of nerve impulses
what is beriberi
result of a long term deficiency where polished rice is a major diet constituent
causes fatigue nerve damage
heart can also be affected on the right side leading to oedema
what is a classic sign of of nerve damage
loss of the ankle jerk reface
what can happen if the right side of the heart is damaged
can lead to oedema
what is wernicke korsakoff syndrome
in developed countries thiamine defieicnes occur in alcoholics
what are the characteristics of wernickes korsakoff syndrome
apathy loss of memory
loss of side to side motion of eyeballs
what are the oral symptoms of vitamin b deficiency
include burning tongue and oral mucosa sensitivity
what is vitamin b6 called
pyridoxine
what is the recommended nutrient index of vitamins b6 in men
1.4mg/days
what is the recommended nutrient index of vitamins b6 in women
1.2mg/day
what can large doses of vitamin b6 cause
severe nerve damage
what are sources of vitamin b6
wheat egg yolk liver fish poultry
what is the function of vitamin b6
pyridoxal phosphate is a co enzyme un mary reactions including transamination and deamination
where can deficiency be seen in people with vitamin b6 deficiency
babies who are fed formula milk
old people
alcoholics
what are the symptoms of b6 deficiency
anaemia
depression
and convulsions
how is pyridoxine attached in the body
to the transminase enzyme in the form of pyridoxal phosphate
what is another name for vitamin e
tocopherol
what is the RNI of vitamin e
it is difficult to establish because deficiency if virtually unknown
what does vitamin e deficiency occur secondary to
lipid absorption disorders as it is absorbed in lipids
what are the sources of vitamin e
8 vitamins related to tocopherols and tocotrienols it is found in vegetable and wheat germ oils green veggies and nuts
what is the function of vitamin e
Vitamin E is an antioxidant. It protects vitamin A, cell membrane components, red
blood cells and low density lipoproteins (LDL) against oxidation- therefore may decrease the risk of heart disease
what is another name for vitamin b2
riboflavin
what is the RNI of riboflavin in men
1.3mg/day in men
what is the rni of riboflavin in women
1.1mg/day
is vitamin b2 toxic
it is non toxic
what are the sources of riboflavin
milk
eggs
liver
what is the function of vitamin b2
active as a flavin mononucelotide and flavin adenine dinucleotide
these are co enzymes and associated with electron carrying in oxidases and dehydrogenase
where can we see deficiency of vitamin b2
in alcoholics and the elderly
what are the symptoms of vitamin b2 deficiency
cracks and inflammation at the corners of the mouth and on the lips and cataracts and glossitis( inflamed tongue)
growth failure
scaliness around nose and ears
what is another name for vitamin b3
niacin
nicotinic acid and nicotinamide
what is the RNI for vitamin b3 in men
17mg/day
what is the rni for vitamin b3 in women
14mg/day
what are some sources of vitamin b3
whole grains milk
meat fish and the AA tryptophan
how much tryptophan is needed to make 1mg of the vitamin b3
60mg of tryptophan is needed for 1mg
what is the function of vitamin b3
active forms are NAD AND NADPH- coenzymes in many reactions
what is pellagra
a side effect of vitamin b6 deficiency characterised by a red rash on skin exposed to the sun and depressive psychosis
what is the rni of pantothenic acid
no recognised rni
what are sources of pantothenic acid
eggs
liver and yeast
what is the function of pantothenic acid
part of co enzyme A
what are the symptoms of pantothenic acid deficiency
rare but fatigue
what is the rni of biotin
none stated
what is the sources of biotin
most foods esp egg yolk
yeast nuts
also synthesised by intestinal bacteria
what is the function of biotin
coenzyme in carboxylation reactions- carries C02
what can consuming huge amounts of raw egg can induce deficiency
dermatitis
what does egg white contain
a protein called avidin which binds biotin and prevents its uptake