Water soluble vitamins Flashcards
They are similar to macronutrients how?
Organic (carbon containing)
Vitamins are what type of compounds
organic
Different to macronutrients how?
not a direct source of energy
What are the water soluble vitamins?
Vitamin C
Coenzymes
B1 (thiamin)
B2 (riboflavin)
B3 (niacin)n
B5 (pantothenic acid)
B6 (pyridoxine)
B7 (Biotin)
B9 (Folate)
B12 (cyanocobalamin)
water soluble vitamins are not stored in what?
not stored in appreciable amounts, so needed regularly from the diet
What happens to excess water-soluble vitamins?
kidneys can excrete in urine, so amount is regulated
are vitamins essential in the diet to promote normal functioning, growth, and maintenance?
yes
although vitamins are not a direct source of energy, they play crucial roles in reactions that extract energy from nutrients. What factors do this?
coenzymes!
What do coenzymes do?
Unlock action of enzymes
Explain the mechanism of coenzymes?
Inactive compound + vitamin B = coenzyme
This coenzyme then attached to an INACTIVE enzyme. Then creates an ACTIVATED ENZYME. allows a molecule to come in and bind to the activated enzyme, which then the active enzyme accelerates the chemical reaction to from one or more new molecules. (splitting of the molecules)
Thiamin (B1)
Function: removes _____ molecule from larger compound
Function: Part of coenzyme ______
Also needed for ________ ________ (e.g. acetylcholine, needed for muscle contraction)
Greatest contribution from diet from _______, ______, or whole-grain products
CO2
Part of coenzyme TPP
synthesis of neurotransmitters
enriched, fortified
Deficiency is called what syndrome:
What happens?
What is the other deficiency?
- degenerative _____ disorder
-primarily _______ induced malnutrition because alcohol reduced thiamin absorption and increases its excretion
resolves if eliminate ____________ and obtain _________ injections
What can destroy thiamin?
BeriBeri
Very weak and poor muscular coordination (deficient acetylcholine production)
Bodies with Hugh energy needs deteriorate first
Wernicke-Korsakoff Syndrome
- degenerative brain disorder
alcohol and obtain thiamin injections
Heat
Riboflavin (B2)
Function: Forms active coenzyme _______
Helps break down _____ ____
Important for ______ formation
Involved directly and indirectly in converting f____, n______, v______ ____, v_______ ___
What can destroy it?
FAD
fatty acids
RBC
folate, niacin, vitamin B6, vitamin K
light
what is the best source of riboflavin (B2)
what is the best practice of storing riboflavin (B2)
Milk
store milk in opaque containers
what other vitamin is sensitive to store lighting for prolonged periods?
vitamin A
what does niacin need riboflavin for?
its formation from tryptophan
What does vitamin B6 need riboflavin for
a conversion to a coenzyme form
Deficiency in riboflavin (B2)
ariboflavinosis
-fatigue
- inflammation of muscous membranes that line the mouth and throat
- Glossitis
- Chapped lips
Niacin (B3)
Function: forms active coenzymes _____, ______
Niacin RDA is expressed as _____
______
1NE = 1mg of niacin or 60 mg of _________
Therefore, 60mg of tryptophan yields _____ ____ _____
NAD, NADP
niacin equivalents
tryptophan, 1mg niacin
Greatest contribution to niacin intake is mixed dished high in _____, ____, ______
Toxicity
Megadoses of niacin may be prescribed to reduce______ and increase______
some side effects include: flushing of skin, tingling sensation in hands/feet, GI upset
meat, fish, poultry
LDL
HDL
deficiency
Ppl at risk: ______,_______. rare disorders that disrupt tryptophan metabolism
Later symptoms f pellagra 4 D’s “rough skin”: _____, _____, ______, ________
Pellagra
alcoholism, anorexia
dermatitis, diarrhea, dementia, death
What other nutrients are needed to convert tryptophan to niacin?
Therefore does deficiency in these nutrients contribute to damage?
iron, riboflavin, vitamin B6
yes
Pantothenic Acid (B5)
Function: Component of ____ (required to make _______)
Function: helps in the production of_______ and ________ hormones
CoA
Required to make Acetyl CoA
stress and sex hormones
Pantothenic acid is _____ damaged
Damaged through: _____, ______, _____, _________
easily
freezing, canning, processing, cooking
there is limited data on pantothenic acid content of food, but as pantothen means ________ it is in lots of different foods like chicken, beef, potatoes, oat cereals
everywhere
Deficiency is virtually _______ in general population
However in research settings: ______, _______
nonexistent
irritability, restlessness
Biotin (B7)
Function: In coenzyme form, biotin participates in ________ _______ that adds _____ ____ other compounds
Essential for_______ _______ in CAC cycle
chemical reaction
CO2
regernation oxaloacetate
Deficiency,
signs of deficiency conclusively demonstrates in individuals consuming ____ ____whites over long periods of time
there is a protein called ________ that is found in raw egg whites that prevents the absorption of biotin. This denatures when cooking.
Deficiency in biotin (B7) is ______
raw egg
avidin
rare
Thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), and biotin (B7) are widespread in the food supply, and overt deficiencies are ______in North America.
They are all incorporated into coenzymes that metabolize ____, ____, _____
rare
CHO, FAT, PRO
T or F There is no RDA, EAR, UL for pantothenic acid or biotin?
T
High doses of______ and________ appear to be harmless, but megadoses of ______should be taken only under medical supervision
thiamine
Riboflavin
niacin
Create a meal (for example, breakfast) that includes Thiamin (B1), Riboflavin (B2), Niacin (B3), Pantothenic acid (B5), and Biotin (B7).
whole grain bread (thiamin B1), glass of milk (riboflavin B2), piece of fish (niacin B3), potatoes (pantothenic acid B5), an egg that’s cooked (Biotin B7)
Vitamin B6
Function: Synthesize _______ and forms ______ blood cells
Cells convert vitamin forms to primary B6 coenzyme pyridoxal phosphate ______
hemoglobin
forms white blood cells
PLP
Folate (B9)
Function: coenzyme involved in______ synthesis and _____ ______ _______
DNA synthesis
amino acid metabolism
What is the difference between folate and folic acid?
Folate refers to a group of related compounds that include folic acid
Folic acid refers to specifically the synthetic form of vitamins found in supplements (and added to fortified foods)
Folate function:
Cell convert folate to group of folate-containing coenzymes _________
tetrahydrofolate (THF)
THF transfers ____ to______; transfers to homocysteine to form________)
THF transfers CH3 to vitB12; transfers to homocysteine to form methionine)
When can folate NOT be used?
When vitamin B12 is not available,
folate can’t be used
What are the three vitamins that work with each other to help control homocysteine levels?
Vitamin B6
Folate (B9)
Vitamin B12
Cells convert vitamin forms to primary B6 coenzyme pyridoxal phosphate (PLP)
Therefore, how does PLP help control homocysteine levels?
PLP converts a potentially toxic amino acid homocysteine to cysteine (a nonessential amino acid)
Vitamin B12
Function: Supports ______ synthesis
maintains _____ ______
Needed for _______ _______
RBC
myelin sheath
Needed for
homocysteine metabolism
Unlike most B vitamins, megadoses of ______ ______are toxic (2-6g/day), causing _______ ______ _______ ____
Vitamin B6
severe sensory nerve damage
What three vitamins correspond to anemias?
Folate (B9), Vitamin B12, Vitamin B6
Folate (B9) ring structure is found in ________ and is ______ bioavailable
Folate polyglutamate is found in ______ and is ______ bioavailable
supplements and is 100% bioavailable
found in foods and is 50% bioavailable
Folate (B9) deficiency
causes what ANEMIA?
Deficiency effects cells that rapidly _____
These immature and larger red blood cells are _______ ________
Megaloblastic Anemia (mega = large; blast = immature)
inefficient O2 carriers
Vitamin B 12 deficiency
causes what ANEMIA?
Low B12 causes low ______
Pernicious (“deadly”) anemia
RBC production
Vitamin B6
deficiency
Causes what ANEMIA?
Low B6 causes deficiency in ______ _________ (protein inside red blood cells that carry O2)
regular anemia
hemoglobin synthesis
Identify FOUR differences between water-soluble vitamins and fat-soluble vitamins.
This is a short answer question on the test
Water soluble vitamins vs fat soluble:
1. B &C vitamins VS A, D, E, K vitamins
- Intestinal cells absorb right into bloodstream vs not absorbed directly into blood stream. these require bile and chylomicrons for absorption.
- not stored in appreciable amounts, so needed from the idea regularly vs stored in appreciable amounts
- excess: kidneys can excrete in urine, so amount is regulated vs excess accumulate in liver and fatty tissues (reserves can last for weeks or months)
What supplements should vegans take and why?
plant foods are not sources of Vitamin B12, so vegans should consider taking supplements of vitamin B12, and should also have fortified foods.
T or F
Unlike most B vitamins, megadoses of B6 are toxic (2-6g/day), causing severe sensory nerve damage (peripheral neuropathy)
T
T of F
If folate intake too high, can mask symptoms of vitamin B12 deficiency anemia until nerve damage is irreversible
T
3 functions of Vitamin C
- Antioxidant activity
- Collagen synthesis
- enhances absorption iron
Vitamin C deficiency
Scurvy
Connective tissues breakdown as body loses its ability to synthesize collagen (gums, joints begin to bleed)
