vitamins from "water soluble vitamins" lecture Flashcards
Which is the first vitamin identified?
Thiamine (Vitamin B1)
Is there toxicity for Thiamine (Vitamin B1)?
None reported
What is the bioavailability for Thiamine (Vitamin B1)?
Sensitive to heat, oxygen, low acid
Antithiamine factors can destroy the vitamin in food (eg: raw shellfish and coffee)
How is Thiamine (Vitamin B1) used in the body?
- Thiamine pyrophosphate (TPP, ThDP and TDP)
- Used in energy producing reactions where carbon dioxide is released
- Used in the synthesis of acetylcholine (neurotransmitter)
- Used in the production of ribose, a precursor to RNA
What does a deficiency in Thiamine (Vitamin B1) look like?
Characterized by lack of energy, weakness and neurological symptoms
(Beriberi - look this up)
A deficiency in Thiamine (Vitamin B1) can result in what neurological condition?
Wernicke-Korsakoff syndrome
* Thiamin deficiency can also be a result of alcohol use disorder
What are the main functions of Thiamine (Vitamin B1)?
Claims to increase energy, improve mental function and prevent heart disease
What vitamin is riboflavin (b2) identified with?
Thiamine
Is there toxicity for riboflavin (b2)?
None reported
What is the bioavailability for riboflavin (b2)?
Sensitive to light Opaque milk cartons are used to preserve riboflavin in milk
How is riboflavin (b2) used in the body?
- Used to make FAD/FADH2 and FMN
- Can transfer electrons to different molecules
- Used in energy producing reactions and transporting electrons to the electron transport chain
- Used in the conversion of other vitamins to active forms
What is a riboflavin (b2) deficiency called?
Ariboflavinosis (look this up)
Increased alcohol consumption is associated with deficiency of which vitamins?
B vitamins
What does a deficiency of riboflavin (b2) look like?
Symptoms include poor wound healing, inflammation of the eyes, lips, mouth and tongue and confusion
What is the purpose/function of taking riboflavin (b2)?
Claims to increase energy and support eye and skin health
When was Niacin (B3) identified?
During the study of pellagra
Niacin (B3) is associated with diets that rely on which food?
Corn
Does Niacin (B3) cause toxicity, if so, what does it cause?
Flushing, nausea, rash, tingling extremities
What is the bioavailability for Niacin (B3)?
Can be made in the body from the amino acid tryptophan, but only when there is enough tryptophan for protein synthesis
What is Niacin (B3) uses in the body?
- NAD+/NADH/NADP+/NADPH
- Transfers electrons to other molecules - – - Used as an electron transporter to generate ATP (energy)
- Use in the body so widespread that deficiency causes damage throughout the body
What is the result of diet deficient in niacin?
Pellegra
What are the symptoms of a niacin (b3) deficiency?
Dermatitis, dementia and diarrhea
If a niacin (b3) deficiency is left untreated, it can result in:
death
What is the purpose/function of niacin (b3)?
Claims to increase energy
When was biotin identified??
in animal studies with rats fed protein from raw eggs
What is the toxicity for biotin?
Non reported
What is the bioavailability for biotin?
produced by bacteria in the GI tract and absorbed into the body
Food containing raw egg should be avoided because the protein avidin in the egg white binds biotin very tightly making it unavailable for absorption
What is the use of biotin in the body?
Co enzyme for COOH- groups on molecules
Generates molecules needed for citric acid cycle and glucose synthesis
What are the symptoms of having a biotin deficiency?
nausea, thinning hair, loss of hair color, red skin rash, depression, lethargy, hallucinations and tingling of the extremities gradually appear
Rare
What is the purpose/function of biotin?
Claims to treat hair loss and brittle nails
Is pantothenic acid widely available in food?
yes
What is the toxicity for pantothenic acid?
Not determined
What is the bioavailability for pantothenic acid?
Susceptible to heat and low or high acid conditions
What are the uses in the body for pantothenic acid?
Part of Coenzyme A (CoA) an important part of Acetyl-CoA Used in the synthesis of cholesterol
When was vitamin b6 identified?
when a deficiency syndrome was discovered that did not respond to thiamine or riboflavin
Vitamin b6 is needed for how many enzymatic reactions?
over 100
Is there toxicity for vitamin b6, if so, what does it look like?
Yes, numbness and nerve damage
What is the bioavailability for vitamin b6?
Easily destroyed by heat and light
Easily lost during processing
What are the uses in the body for vitamin b6?
Used in amino acid metabolism
Used in transamination and deamination reactions
Needed to synthesize hemoglobin
Needed to form white blood cells
Needed for the conversion of tryptophan to niacin
Metabolism of glycogen
Synthesis of neurotransmitters
Synthesis of myelin coating on nerves
Symptoms of a deficiency in vitamin b6?
- Neurological symptoms include depression, headaches, confusion, numbness and tingling in extremities and seizures
- Anemia
- Poor growth, skin lesions and decreased antibody formation may occur because vitamin B is important in protein and energy metabolism
What is the purpose/function of vitamin b6?
Reduces CVD (reduced levels of homocysteine) Improves immunity in older adults
How was folate identified?
Identified as a group of compounds that were part of Wills Factor and used to treat anemia during pregnancy
Is there toxicity for folate, if so, what may result?
No, BUT can mask a vitamin B12 deficiency
What is the bioavailability for folate?
- bound to chains of glutamate which must be removed prior to absorption - only 50% of dietary folate is absorbed - synthetic folate does not contain glutamate and is more readily absorbed
What are the uses in the body for folate?
amino acid metabolism
synthesis of DNA (DNA replication)
DNA methylation (silencing of gene expression)
Symptoms/signs of a deficiency in folate?
Megaloblastic anemia
Neural tube defects such as spina bifida and anencephaly
Heart disease (increased homocysteine levels)
What is the function/purpose of folate?
masks vitamin B12 deficiency To prevent neural tube defects ( about 28 days gestation), advised that mom take folate
What is pernicious anemia caused by?
by an inability to absorb sufficient vitamin B12
What is the toxicity for vitamin b12?
None reported
What is the bioavailability for vitamin b12?
- Found mostly in animal products, can be made by bacteria and fungi
- ppl who are vegan must get vitamin B12 from nutritional yeast or a supplement
- Vitamin B12 is inaccessible within food prior to digestion
- in the stomach, acid and pepsin release it from bound proteins in food
- In the small intestine, binds to receptors in the ileum and be absorbed - Very little vitamin B12 is lost in the body therefore deficiency develops slowly
what are the uses in the body for vitamin b12?
amino acid metabolism and the synthesis of methionine Regenerates folate
What is atrophic gastritis?
a reduction in the amount of stomach acids impairs the ability to release vitamin B12 from food
Signs/symptoms of a deficiency in vitamin b12?
anemia
Neurological symptoms, which include numbness and tingling, abnormalities in gait, memory loss and disorientation
If left untreated this can lead to paralysis and death
What is the function/purpose of vitamin b12?
Supplemental folate masks vitamin B12 deficiency
Ppl with vegan diet
Recommend for elderly
Claims include “pick me up” for tired individuals
Dietitians estimate that ⅓ of the population may have low vitamin B12 levels
Is there toxicity for vitamin c, if so, what are the symptoms?
Extreme doses may cause diarrhea, nausea and abdominal cramps
What is the bioavailability for vitamin C?
Vitamin C is unstable and is destroyed by oxygen, light and heat Reactive with copper or iron cooking utensils and by low acid conditions
What are the uses in the body for vitmamin C?
maintenance of connective tissue stemming from the formation of collagen Crosslinks collagen proteins to form stronger fibers Synthesis of neurotransmitters, hormones and bile acids Acts as an antioxidant Supports the immune system Aids in iron absorption
Is there a deficiency for vitamin c, if so, what are the symptoms?
connective tissue breaks down, wounds heal poorly, weakening blood vessels
Poor iron absorption (anemia)
What is the deficiency for vitamin c called?
Scurvy
What is the function/purpose of vitamin c?
Prophylactic - may reduce the duration of a cold
antioxidant
protect against CVD
cancer prevention
