Vitamin C, Niacin, Thiamine Flashcards
where is vitamin c found
-present in many rapidly growing foods
how can vitamin c get degraded?
-storage and food preparation
characteristics of vitamin c in small intestine
-dose dependent and residual large doses can cause bloating and diarrhea
metabolite of vitamin c
-oxalic acid
4 broad roles of vitamin c
- antioxidant
- contributes to protein and neurotransmitter metabolism
- can facilitate absorption of non-heme iron
- has a role in two stages of collagen synthesis
risk of vitamin c def
- poor diet
- intestinal disease or malabsorption
- alcoholics
when is the vitamin c RDA increased
- in smokers
- however, this by itself will not lead to a flat out def
Vitamin C leads to Scurvy which has the following symptoms
- bleeding (petechiae and ecchymoses)
- impaired soft tissue integrity such as poor wound healing or bleeding gums
- impaired growth and bone growth
- CNS alterations in mood and mental status
- infection
vitamin c toxicity
-symptoms
- usually occurs due to supplement use
- bloating
- diarrhea
- may increase the risk of oxalate kidney stones in susceptible users
thiamine is found in
-a variety of foods including grains and animal foods
thiamine degradation and enrichment
- may be degraded during processing so the grain is enriched
- may also be due to thiaminases or antithiaminases but this is rare
alcohol and thiamine
- impairs the transport of thiamine after it has been absorbed in the small intestine as well as impairs its phosphorylation into its active form
- this contributes to thiamine def in alcoholics
body pool and intake requirements
- body pool is 30mg which is roughly equal to 30 days of intake
- this means we need a fairly regular intake
transketolase and thiamine
- involved in the pentose phosphate pathway
- this forms the basis of a diagnostic test for deficiency
dehydrogenases and thiamine
- pyruvate dehydrogenase
- without this enzyme you will get an accumulation of lactate
