Water Soluble Vitamins (Vit. B and C) Flashcards
Vitamins
Any of the various organic substances obtained from feedstuffs that are essential in small quantities for normal metabolism and health of most animals;
A common Vitamin C defeciency in british sailors?
What is the vitamin specifically called that helps treat/prevent it and what food source can it be found in?
Scurvy was common among sailors in 1500s
It could be treated/prevented by Ascorbic acid which is found in lemon juice. (this was discovered in the 1750’s)
Vitamin C structure?
Sensitive to?
Synthesize?
•Ascorbic acid
- Sensitive to destruction from light and heat;
- Most animals can synthesize vitamin C from glucose; in the liver
Where is Vitamin C synthesized?
in the liver (from glucose)
What are some animals that are unable to synthesize Vitamin C and must depend on dietary sources?
humans, most primates, guinea pigs, bats, capybaras, some birds and fish.
Sources of Vitamin C in foods?
Fruits and Vegetables
Sources of Vitamin C in supplements?
L-ascorbic acid or sodium ascorbate.
Sources of Vitamin C Natural vs Synthetic (man made)
These two forms are chemically identical and there are no known differences in their biological activities or bioavailabilities.
One is not better for you then the other
Absorption of Vitamin C
Ascorbic acid is absorbed in the body by both active transport and simple diffusion.
*active transport is only used when consuming low amounts of Vitamoin C to prevent a deficiency
Vitamin C is NOT stored but it is concentrated in tissues, what tissues are they? (5 of them)
Biological tissues that accumulate over 100 times the level in blood plasma of vitamin C are the;
adrenal glands, pituitary, thymus, corpus luteum, and retina.
*its thought that Vitamin C is critical in these tissues
Functions of Vitamin C?
- Vit. C is one of the the several water-soluble antioxidants with in a cell (heps prevent free radicals)
- Can also regenerate vitamin E
- Cofactor needed for healthy collagen formation, a major type of connective tissue. (Cross-linkning?) < look up
Minor Funcitons of Vitamin C include
Vit. C also plays an important role in the synthesis of the neurotransmitter, norepinephrine.
Vit. C is required for the biosynthesis of carnitine, a small molecule that is essential for the transport of fat into mitochondria, where the fat is converted to energy. (if deffecient causes fatigue)
Vit. C is involved in the metabolism of cholesterol to bile acids, which may have implications for blood cholesterol levels, fat digestion and the incidence of gallstones.
Vitamin C - Deficiency Scurvy is characterized by what?
Scurvy is characterized by weakness, anemia, bruising, bleeding gums and loose teeth.
Vitamin C - Requirements
**No requirements for livestock animals; (they can synthesize it themselves)
Humans:
60-100 mg/day
Bioflavonoids association with Vitamin C?
Bioflavonoids are a class of water-soluble plant pigments that are often found in vitamin C-rich fruits and vegetables, especially citrus fruits.
Vitamin C - Toxicity
- Little risk of toxicity
However, because oxalate is a metabolite of vitamin C, there is some evidence that high vitamin C intake can increase the risk of oxalate kidney stones.
Vitamin B was ince thought ti be a single vitamin when inturn they are?
they are chemically distinct vitamins that often coexist in the same foods.
Deficiencies, when present, usually occur for multiple B vitamins (clustered)
What does “vitamin B complex” reffer to?
Supplements with all eight B Vitamins
Vitamin B1
Thiamin/Thiamin
Vitamin B2
Riboflavin
Vitamin B3
niacin, nicotinic acid, & nicotinamide
Vitamin B5
pantothenic acid
Vitamin B6
pyridoxine, pyridoxal, & pyridoxamine
Vitamin B7
Biotin
*usually referred to as this
Vitamin B9
Folic acid
*Usually referred to as this
Vitamin B12
various cobalamins; cyanocobalamin in vitamin supplements
*usually just referred to as Vitamin B12
B vitamins - Roles in metabolism
What do thiamine, riboflavin, niacin,
pantothenic acid, biotin do in relationship with metabolism?
helps the body use energy-yielding macronutrients
B vitamins - Roles in metabolism
What is pyridoxine (B6) apart of with metabolism?
Protein metabolism
B vitamins - Roles in metabolism
cobalamin (B12) & folate assist with what dealing with metabolism?
Cell proliferation/regeneration
B vitamins - 3 Roles in metabolism
- Some helps the body use energy-yielding macronutrients
- Protein metabolism
- Cell proliferation/regeneration:
What vitamins helps the body use energy-yielding macronutrients associated with metabolism?
(5 of them)
- *thiamine** (B1), riboflavin (B2), niacin (B3),
- *pantothenic acid** (B5) and biotin (B7)
What vitamin helps with Protein metabolism
pyridoxine (B6)
What vitamins assist with Cell proliferation/regeneration with metabolism?
cobalamin (B12) & folate (B9)
Thiamin (B1) - Functions
Vitamin B1 (Thiamine) helps the body convert food into energy,
and aids the function of the heart and **cardiovascular system **and the brain and nervous system
Thiamin functions
Thiamin is a cofactor (i.e., a helper molecule)
required by enzymes involved in two key
pathways of carbohydrate metabolism.
- Transketolase (Pentose phosphate shunt)
- Pyruvate dehydrogenase (PDH) >glucose metabolism
- alpha–ketoglutarate dehydrogenase
Intermediate products of these pathways are needed for the
generation of other essential molecules in the cells
(e.g., building blocks of proteins and DNA as well as brain chemicals).
Inadequate thiamin affects?
Inadequate thiamin affects all organ systems,
however,
cells of the nervous system and heart seem
particularly sensitive to the effects of thiamin deficiency.
A reduction in thiamin status can interfere with?
numerous cellular functions, leading to serious brain disorders, including
Wernicke–Korsakoff syndrome,
which is found predominantly
in alcoholics.
Wernicke–Korsakoff syndrome occurs when?
What kind of people is it predominatly found in?
reduction in thiamin status can interfere with numerous
cellular functions, leading to serious brain disorders including
Wernicke–Korsakoff syndrome, which is found predominantly
in alcoholics.
Thiamin (B1) - Sources
Commmon sources include Brewers yeast (very common/good source of B1) and molasses
also found in fortified breads, and cereals, fish, lean meats and milk
Thiamin (B1) in livestock…
Deficiency in chicks leads to?
Dificiency in pigs leads to?
Deficiency in chicks leads to polyneuritis (paralysis),
but in pigs it leads to heart failure
What animal can store
appreciable amounts of thiamin in tissues?
Pigs
Thus, pork is an excellent dietary source of thiamin.
What type of animal/food source contain high levels
of enzymes that degrade thiamin?
Fish and other seafood may contain high levels
of enzymes that degrade thiamin (i.e., thiaminases),
**thus feeding raw seafood can precipitate a deficiency
(cooking destroys these thiaminases!)
Why do 80-90% of alcoholics suffer from CNS
damage associated with thiamin deficiency?
Alcohol interferes with thiamin utilization in the cells.
Riboflavin (Vit. B2) works with other B vitains to promote what?
Healthy growth, skin, RBC production and tissue repair, and energy from carbohydrates
Riboflavin (B2) functions as the ESSENTIAL compopnent of what 2 coenzymes?
FAD (biological oxidizing agent) and FMN
In most animals, riboflavin deficiency results in lack of?
growth, failure to thrive, and eventual death.
Riboflavin deficiency is classically associated with the
oral-ocular-genital syndrome including what symptoms?
cracked and red lips,
inflammation of the lining of mouth, tongue mucus
membranes, corneal opacity.
Food sources of Riboflavin (Vit. B2)
cereal, nuts, milk, eggs, green leafy vegetables and lean meat
brewer’s yeast and molasses
- Yellow in color;
- Heat stable, but destroyed by light;
- Milling results in up to 60% loss.
Absorption of Riboflavin is by?
What is it excreted through?
- Absorption is by passive diffusion.
- Excreted in the urine, giving it a bright color.
**only a little is stored in liver