ppwt 4 micronutrients during adulthood Flashcards
thiamin function as a
coenzyme in the metabolism of carbohydrate and branched chain aa
requirement of thiamin is based on what
- thiamin needed to achieve and maintain RBC transketolase activity
- without excessive thiamin excretion - if there is no excretion it means that the body needs more
what is a known biochemical function of thiamin
thiamin pyrophosphate
to determine the estimated required of thiamin for men and women do you need to take into consideration the energy utilization and the size
yes because they don’t have the same size and energy utilization so men will have an EAR and RDA bigger than the women
What is the function of riboflavin
coenzyme in numerous oxidation-reduction reactions
riboflavin is required based on
- erythrocyte glutathione reductase activity coefficient
- RBC
- Urinary riboflavin excretion (when you have a lot of riboflavin the urine becomes very yellow)
For riboflavin EAR for adults derived from what
- studies of the occurrence of signs of clinical deficiency
- biochemical values
- urinary excretion in relation to dietary intake
what is the function of niacin
cosubstrate or coenzyme for H- transfer (dehydrogenase )
what is the primary criterion for RDA for niacin
urinary excretion of niacin metabolites
does niacin has an UL. What is the consequence if you go over
yes of 35 mg- liver damage
Vitamin B6 is an coenzyme
coenzme in metabolism of aminos acid’s glycogen, and sphingoid bases
what is the primary criterion used to estimate RDA of vitamin B6
maintenance of adequate blood 5’ pyridoxal phosphate levels - bioactive form
does vit b6 has an ul, what is the consequence if you go over
yes you have nervous failing
what is the function of folate
coenzyme in single carbon transfer in the metabolism of nucleic and amino acid
what is the primary indicator for RDA estimates
- erythrocyte folate - the blood levels drop
- blood (homocysteine) and (folate)
rda of folate is based on
dietary folate equivalents (DFEs)
DFEs adjust for ~50% lower bioavailability of food folate vs folic acid
folate is less bioavailable in food or folic acid ( fortified food or supplement)
it is less biovailable in food folate
when women are pregnant their need for folate is higher than the UL
yes - their need for folate is 4mg and the ul is 1mg
vitamin B 12 functions
coenzyme for methyl tranfer reaction
homocysteine -> methionine
L-methylmalonyl conezyme A -> succinyl-CoA
vitamin B 12 functions
coenzyme for methyl tranfer reaction
homocysteine -> methionine
L-methylmalonyl conezyme A -> succinyl-CoA
RDA dor vit b12 is based on
maintenance of hematological status and normal blood vitamin B12 values
What is the function of biotin
coenzyme in bicarbonate dependent carboxylation reaction
is deficiency for biotin rare
it is very rare you can se edeficiency in inborn error
choline is important for
acetylcholine, plasma lipid stability. It is a precursor for acetylcholine phospholipis an methyl donor betaine - help methylation process
what is the primary criterion used to estimate the AI for choline
prevention of liver damage as assessed by serum alanine aminotransferase level
how can you find choline in the diet
- free choline
- bound to ester (phosphocholine, sphingomyelin, phosphatidylcholine etc)
why it is phosphatidylcholine important
it is important for the plasma menbrane, if you on’t have enough your liver cannot excree VLDL so ecsess liver fat -> cause cellular damage and it can cause low choline so liver damage
if you don’t have … it can cause methionine deficiency
tetrahydrofolate
is methionine important to make choline
yes
true or false
we have insufficient data for EAR of choline
true
choline requirement is influenced by
- methionine and folate availability
- gender, pregnancy lactation, stage of development
is there an UL for choline
yes
pantothenic acid (vit b5) is a component of
coenzyme A and phosphopantetheine (fatty acid metabolism)
pantothenic acid (vit b5) is a component of
coenzyme A and phosphopantetheine (fatty acid metabolism)
true or false
pantothenic acid is widely distribute in foods
true
how can you be deficient of pantothenic acid
semisynthetic diets or antagonist to the vitamin
how o you estimate the AI of pantothenic acid
intake adequate to replace urinary excretion of pantothenic acid
what is the function of vit c
- water soluble antioxidant
- cofactor fo enzymes involved in biosynthesis of collagen, carnitine and neurotransmitters
rda based on vit c intake to
- maintain near maximal neutrophil concentration
- minimal urinary excretion of ascorbate
vit a is important for
- normal vision
- gene expression
- reproduction
- embryonic development
- growth
- immune function
the ear fo vit A is based on
assurance of adequate stores
what is the difference between preformed vit a and provitamin a
preforme vit a: some animal derived food
provitamin a carotenoids: darkly colored fruits and vegetables, oily fruits and red palm oil
what is use for setting vitamin A requirements
retinol activity equivalents
dietary provitamin A carotenoids
beta carotene
alpha carotene
beta cryptoxanthin
EAR of vit A is based on what
based on amount of dietary vitamin A required to maintain a given body pool size in well nourished subjects
can vit a build up
yes- there is an UL
the function of vit d
- increase absorption efficiency of small intestine (Ca, P) and maintain blood calcium and p
- potent antiproliferative and prodifferentiation effects in a variety of tissues
what are the 2 types of vitamin D
vitamin D2 (ergocalciferol - yeast and plant steros)
vitamin D3 ( cholecalciferol, from 7 dehydrocholesterol)
is vit d found in food
found in a few foods more synthesized in the skin
deficiency of vit d lead to
rickets - infant
osteomalacia - adults
what happens if we pass the ul of vit d
it can cause hypocalcelemia - decrease in calcium
what is the major function of vit E
Non-specific chain breaking antioxidant preventing the propagation of lipip peroxidation
rda of vit e is based on
- induced vit E deficiency in humans
- correlation between H2O2 induced erythrocyte lysis and blood (the higher the vit E the less chance rdc will damage)
which form of vit E is taken into consideration when making the rda
tocopherol because it is saturated - the liver has an receptor for it and it secretes for other tissues
what form of vit E supplementantion is fucntional
The 2R form it is maintained by humans (1st position needs to be an R)
the RRR-alpha tocopherol is maintained where
human plasma
however the synthetic SRR alpha-tocopherol or natural gamma-tocopherol is maintained where
absorbed in the liver but poorly packaged into lipoproteins for delivery to peripheral tissues
for the vit e the EAR, RDS, AIs apply only to the … form
2R stereoisomeric
if you pass the ul for vit e what can happen
increase bleeding, cancer patient can be counter rpoductive bc they will kill radicals to kill cancer cells, low vit c sotroes and lipid oxidation
function vit k
coenzyme during synthesis of biologically active form of a number of proteins involve in blood coagulation and bone metabolism
what are the 2 form of vit K
phylloquinone (major form )
menaquinones - produced by bact in the lower bowel
what is the benefits of menaquinones
good for bone formation
found in fermenteted foods + animal products.
More bioactive and it is active for hours
function of calcium
- second messenger
- primary bone mineral
how many people does not meet Ca reqt
50%
who is more in a higher risk of calcium deficiency
women, because they don’t have so much bone mineral in the first place
what happens when you exceed the UL for calcium
hypercalecemia - can pose risk of cardiovascular
where is phosphorus mainly found
bone
what is the function of phosphorus
buffers acid or alkali in excess to maintain normal ph
how much of the phosphorus is absorbed
60 to 65% bc of the biovailability
where is magnesium mostly found
bone
ear of magnesium is based on what
total body mg
