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
Toxicity of Vitamin B2 (Riboflavin)
Toxicity unlikely, unless very large
amounts are injected.
Niacin = nicotinic acid = nicotinamide (Vit. B3)
The term niacin refers to nicotinic acid and
nicotinamide, which are both used by the
body to form what two coenzymes?
- nicotinamide adenine dinucleotide (NAD)
& - nicotinamide adenine dinucleotide
phosphate (NADP).
Niacin (B3) - Functions
Living organisms derive most of their energy from
oxidation-reduction (redox) reactions, which are
processes involving what?
The transfer of electrons
As many as 400 enzymes require the niacin
coenzymes, NAD and NADP, mainly for what?
to accept or donate electrons for redox reactions.
What tissues are most sensitive to Thiamin deficiency?
Brain and Heart
NAD functions most often in reactions involving what?
the degradation (catabolism) of carbohydrates, fats,
proteins, and alcohol to produce energy.
NADP functions more often in what?
biosynthetic (production; anabolic) reactions, such as in the synthesis of fatty
acids & cholesterol.
What serves as a precursor for niacin
biosynthesis?
Tryptophan (TRP)
*Inefficient process:
60 mg of TRP = 1 mg NIACIN
Vit. B3 deficiency = “pellagra”
The symptoms of pellagra are commonly referred to
as the three D’s which include?
dermatitis, diarrhea, & dementia.
*A fourth D, death, occurs if pellagra is left untreated.
Species-specific symptoms with Vit. B3 deficiency in poultry include?
poor feathering, “speckled eye”
Species-specific symptoms with Vit. B3 deficiency in swine include?
ulcerated intestines, diarrhea, vomiting
*more dealing with GI track
Species-specific symptoms with Vit. B3 deficiency in Dogs include?
mouth lesions, “black tongue”
Species-specific symptoms with Vit. B3 deficiency in Humans include?
bright red tongue, mouth lesions
Diet Sources of Vitamin B3 include?
Brewer’s yeast, wheat germ, cereal grains*,
peanuts and other legumes, some fruits & vegetables.
*Cereal grain niacin is poorly UNAVAILABLE to monogastrics.
(corn is tightly bound and must be exposed to alkaline to break bonds to be more availabe)
Native Americans and Mexicans knew to soak ground corn in lime (calicum oxide) which **_freed the niacin._**
Vitamin B3 absorption through?
Mostly occurs where?
passive diffusion mostly in small intestine
Vitamin B3 requirements in Ruminants
No diet requirement in adult ruminants
since rumen microbes make plenty vit. B3
Vitamin B3 – Toxicity
Excess niacin can lead to:
Acute: skin flushing, severe itching, skin rashes.
Chronic: liver damage.
Nicotinic acid used to reduce
- serum cholesterol in patients with hypercholesterolemia;
- Sometimes used to treat schizophrenia
*Pharmaceutical doses (3-9 g/day)
Pantothenic acid – rarely referred to as vit. B5
Sources?
1. Widely distributed in feedstuffs
(“pantos” means “everywhere” in Greek);
2. Rumen & hind-gut microbes make it too!
Pantothenic acid (B5) has what type of absorption?
Absorption: saturable, sodium-dep. active
transport process in small intestine.
*unecessary to use since it can be produced
Pantothenic acid - functions
- Essential component of coenzyme A (CoA)
- Essential component of acyl carrier proteins (ACP),
Pantothenic acid - functions
1. Essential component of coenzyme A (CoA)
Key role? and needed for what?
- Key role in Krebs cycle;
- Needed for production of some neurotransmitters
Pantothenic acid - functions
2. Essential component of acyl carrier proteins (ACP)
used for?
Used for fatty acid & cholesterol biosynthesis
Pantothenic acid – deficiency
Deficiency is rare, but if it occurs, the symptoms include:
- Reduced growth rate
- Nerve dysfunction (Goose-stepping from nerve degeneration)
- Skin lesions
- Fatty liver
- Rough hair & loss
- Impaired reproduction
Pantothenic acid associated with stability
Poor stability: pantothenic acid belongs to the least stable of the B vitamins
• grinding grain - losses reach up to 50%
• roasting meats – losses from 25 to 50%
Pantothenic acid Toxicity
• Very low risk;
• One case of accidently synthetic
pantothenic acid intake of over 10 g a
day that resulted in diarrhea.
Vitamin B6 – 3 chemical forms
Pyridoxine
Pyridoxal
Pyridoxamine
Vitamin B6- Functions
- *Biologically active form of vitamin B6 **
- pyridoxal phosphate (PLP)
Involved in amino acid and N metabolism
(Thus requirement increase with high protein diets!)
“PLP” serves as a coenzyme for
- transaminases
- deaminases
- decarboxylases
- phosphorylases
Transaminases
– needed for production of non-essential amino acids.
Deaminases
– needed for catabolism of amino acids
Decarboxylases
- remove carboxylic acid groups from organic compounds.
(e.g., conversion of glutamate to GABA, a neurotransmitter)
Phosphorylases
– adds phosphate groups to various compounds.
(e.g., Glycogen phosphorylase catalyzes the rate-limiting step in glycogenolysis)
Vitamin B6 – Absorption/Transport
Absorption of all 3 chemical forms is by?
Diffusion
Vitamin B6 – Absorption/Transport
What is the major transport form in the blood?
Pyridoxal is major transport form in the blood
and is tightly bound to albumin
Vitamin B6 – Absorption/Transport
What is the major site of Vitamin B6?
Muscle is the major site of vitamin B6, mostly due to its
presence in glycogen phosphorylase.
(key muscle enzyme)
Vitamin B6 – Absorption/Transport
What is the primary route of elimination of Vitamin B6?
Urine is primary route of elimination
Vitamin B6 – Absorption/Transport
What is used as an indicator of B6 status?
Urinary [pyridoxic acid] is used as an indicator of B6 status.
Vitamin B6 - Food Sources
Food sources of vitamin B6 (pyridoxine) include;
beans, legumes, nuts, eggs,
meats, fish, breads and cereals
Vitamin B6 Deficiencys
Deficiency…
1. Associated with problems in the CNS,
leading to convulsions in all animals & people;
-
Unlikely in farm animals, because B6 is widely
distributed in common feedstuffs.
Vitamin B6 – Toxicity
- Vitamin B6 (pyridoxine) causes neuropathy at
intakes of 1000 mg per day or more, which is
about 800 times the daily intake from foods. - Toxicity cannot occur from eating natural foods.
Vitamon B7 is more commonly known as what?
“Biotin”
(also known as vitamin H or
coenzyme R, rarely called B7)
Vit. B7 (Biotin) requirements
Biotin is required by all organisms,
but can be synthesized only by bacteria, yeasts, molds,
algae, and some plant species.
What is the main function of Biotin in metabolism?
Or
Biotin is the cofactor required of
enzymes that are involved in what?
Biotin is the cofactor required of enzymes that are involved in
carboxylation reactions.
Carboxylation Reactions in biotin includes?
1. acetyl-CoA carboxylase (makes malonyl CoA)
2. pyruvate carboxylase (makes OAA)
(Needed to keep TCA cycle going when
components are being used for various biosynthetic pathways)
(Needed for f_atty acid & cholesterol biosynthesis_)
Which enzymes are biotin dependent?
(4 of them)
- Malic Enzyme
- Pyruvate Carboxylase
- Pyruvate Dehydrogenase
- Glutamate
Which food is a good source of Biotin but can also lead
to a defiency if it is eaten uncooked?
Eggs
Biotin – Sources in food and
what organisms can synthesize it?
- Egg yolk, liver, and yeast are rich sources;
- Synthesized by intestinal bacteria in
ruminants & hind-gut fermentors.
Biotin - Deficiency
Deficiencies are rare, except…
- after long-term antibiotic therapies;
- Excessive/frequent consumption of raw eggs.
(The latter is due to the affinity of the egg white protein,
avidin, for biotin preventing intestinal absorption of the
biotin. Cooking eggs destroys avidin.)
Symptoms of biotin deficiency:
extreme exhaustion, drowsiness, muscle pain,
loss of appetite, depression, & grayish skin color.
Additional biotin has been shown to improve hoof hardness, integrity
and conformation in equine & swine.
Biotin Toxicity?
Biotin is not known to be toxic
Large doses of pantothenic acid (vitamin B5) have
the potential to compete with biotin for intestinal and
cellular uptake due to their similar structures.
Biotin with hair loss and brittle nails
Do B vitamins boost energy drinks’ power?
B vitamins have become the new go-to ingredients for a quick pickme - up.
Which amino acid can be made in to Niacin?
Trytophan
Vitamin B9 also known as?
Most commonly known as Folic acid
(folate, folacin, or vitamin M)
Bracken fern poisoning causes
which B-vitamin deficiency in
horses?
Thiamin
Folic Acid (B9) Functions?
The function of folate derivatives is to carry
and transfer various forms of one carbon
units during biosynthetic reactions.
These one carbon transfer reactions are required in
the biosynthesis of the following amino acids:
(3 Amino Acids)
serine, methionine, glycine
These one carbon transfer reactions are required in the
biosynthesis of choline and purine nucleotides needed for:
- Phospholipid synthesis for cell membranes
- DNA & heme biosynthesis
These are important for new cell formation,
such as early during pregnancy and with
tissue repair & growth.
A deficiency of folic acid or B12
results in a blood disorder called?
Megaloblastic anemia
Folic acid – Deficiency
3 deficiency symptoms
- Low birth weight
- Megaloblastic anemia*
- Neural tube defects* (spina bifida)
What is Megaloblastic anemia?
A disorder in which red blood cells are larger than normal,
immature, and few in number, which reduces the amount of
oxygen that can be carried by the blood to the body’s tissues.
What is Neural tube defect (spina bifida)?
Occurs BEFORE you know you are pregnant, that is why
doctors encourage women to start taking pre-natal vitamins
BEFORE you start your family.
All neural tube defects occur between the 17th and 30th days
following conception.
Folic Acid sources
Liver, Yeast, Nuts, Dried beans, Whole grains,
Spinach and other leafy greens, Oranges and Avacados
Deficiences of Folic acids in farm animals?
Deficiencies in farm animals are rare,
due to them being widely available in comon feedstuffs
Ruminants do NOT have a dietary
requirement for B12 but they do need a
source of what mineral so their microbes
can synthesize B12?
Cobalt
What is the reson Cobalt is required with Vitamin B12 (cyanocobalamin)?
Essential cobalt in the center of ring structure
(Dark red crystalline compound)
(only reason COBALT is required!)
Vitamin B12 (cyanocobalamin)
- Coenzyme in several enzymes, including the
enzyme needed for methionine biosynthesis; - Plays an important role in “methyl group” metabolism;
- Works with folic acid;
Folate and B12 interact with which other B vitamins
in the metabolic inter-change of methionine and cysteine?
***
- Riboflavin
- Pyridoxine
B12 deficiency
- Megaloblastic anemia
Pernicious anemia
**If the deficiency is not corrected, it can permanently damage the nerve cells.
(just like with folic acid def.)
What is Pernicious anemia?
A condition in which there is a lack of a protein called intrinsic factor.
The protein, which is made by the stomach, is necessary for vitamin
B12 absorption.
B12 absorption:
3 Steps?
Step #1: Intrinsic factor (IF) is secreted by the stomach.
Step #2: IF and B12 combine in the small intestine during digestion of foodstuffs.
Step #3: IF-B12 complex is absorbed in the ileum.
Antacids and gastric by-pass surgery
can severely limit IF secretion and
subsequent B12 uptake.
Inflammatory bowel diseases can
also lead to poor B12 uptake.
B12 Sources
• Exclusively in animal products: meat,
eggs, bone & meat meals.
• It’s the only vitamin we can’t obtain
from plants or sunlight.
• Plants don’t need B12 so they don’t
make it or store it.
B12 and livestock nutrition
- Cobalt (Co) needed for B12 synthesis in rumen.
- Newborn calves need 45-60 days to have functional rumen so it can be synthesized…
– Usually get enough from mother’s milk.
– Stressed/weaned calves may be helped w/ a B12 shot. - Swine & poultry definitely need it added to rations or from a shot.
- Deficiency = anemia, poor growth & repro,
hatching problems with chicks.
A dog with a “black tongue” might be
suffering from a deficiency of which
B-vitamin?
Niacin
Which adult animals definitely do NOT have a
dietary requirement for any B vitamins?
Sheep
**Dont have to worry about requirement in adult rumen animals
