NUTR 2105 Lecture 10: Chapter 10 Water-Soluble Vitamins
1 May 2018
School
Department
Course
Professor
There are nine water-soluble vitamins
Vitamin C
○
Eight B-complex vitamins
Initially thought to be one vitamin
§
Years of research uncovered it was several substances
Thiamin
□
Riboflavin
□
Niacin
□
Vitamin B6
□
Folate
□
Vitamin B12
□
Pantothenic acid
□
Biotin
□
§
○
Easily destroyed by heat, light, and oxidation
○
Traits of water-soluble vitamins vs fat-soluble vitamins
○
-
Digesting and Absorbing Water-Soluble Vitamins
-
Primary Functions of Water-Soluble Vitamins
B vitamins act as co-enzymes in many metabolic processes
Act as coenzymes to catalyze the enzyme to build or break apart
compounds
§
Transform carbs, proteins, and fats to ATP
Thiamin
□
Riboflavin
□
Niacin
□
Pantothenic acid
□
Biotin
□
Vitamin B6
□
§
B Vitamins Function as Coenzymes
§
Water-soluble vitamins in other critical roles:
Antioxidant: vitamin C
□
Nerve function: thiamin
□
Protein synthesis: niacin
□
Formation of red blood cells: folate and vitamin B12
□
Several B vitamins promote heart health
□
§
B Vitamins Function in Energy Metabolism
§
○
-
Thiamin (B1)
First B vitamin discovered
Casimir Funk identified thiamin as the curative factor in unpolished
rice in 1911
§
○
Dietary form converted to active coenzyme form thiamin pyrophosphate
(TPP)
○
It is destroyed in basic; acid solution protect it
○
Absorption
In jejunum by passive diffusion
§
Active transport is used w/ low intakes
§
Transported through the blood and excreted through urine
§
○
Structures of Thiamin and Thiamin Pyrophosphate
○
Metabolic Functions
Produces ATP from carbohydrate metabolism
TPP activates decarboxylase to remove a carbon from
pyruvate; forms acetyl CoA
□
TPP-dependent enzymes convert alpha-ketoglutarate to
succinyl CoA in the TCA cycle
□
§
Converts branched-chain amino acids to acetyl CoA
§
Makes pentoses used to synthesize DNA and RNA (so can't make
those w/o thiamin)
§
Transmission of nerve impulses (non-metabolic function)
§
The Function of Thiamin Pyrophosphate in Energy Metabolism
§
○
Daily Needs and Food Sources of Thiamin
Major food sources:
Enriched and fortified foods (remember these add back
vitamins b1, b2, and b3)
□
Whole-grain foods□
Lean pork (ham and bacon)□
§
○
Thiamin Toxicity
No known toxicity
§
○
Thiamin Deficiency
Berbiberi
Symptoms include loss of appetite, weight loss, confusion,
muscle weakness, peripheral neuropathy
□
Classifications
Wet: edema and congestive heart failure
®
Dry: muscle wasting w/o edema or nerve degeneration
®
□
§
Wernicke-Korsakoff syndrome
Caused by chronic alcohol abuse□
§
Causes of deficiency:
Inadequate dietary intake□
Malabsorption□
Alcoholism□
Prolonged diarrhea□
Times of increased need w/ too little intake
Pregnancy and lactation
®
□
§
○
-
Riboflavin (B2)
Composed of a side chain and ring structure
○
Two coenzyme forms
Flavin mononucleotide (FMN)
§
Flavin adenine dinucleotide (FAD)
§
○
Stable during cooking except in the presence of UV light
○
Absorption
Attached to proteins in food
§
Released in the presence of hydrochloric acid in the stomach
§
Absorbed by active transport in the small intestine
§
○
Structures of Riboflavin and the Coenzyme Forms of FAD and FMN
○
Metabolic Functions
Participates in energy metabolism through oxidation
FAD and FMN accept hydrogen ions (H+)□
FADH2 transports electrons to the electron transport chain to
make ATP
□
Participates in beta-oxidation□
Participates in oxidation-reduction reactions that protect cells
from oxidative stress
□
§
Enhances the function of other B vitamins
§
Role of FAD in the TCA Cycle
§
○
Daily Needs and Food Sources
Major food sources
Milk □
Yogurt□
Enriched and fortified cereals and grains□
§
○
Riboflavin Toxicity
None; excessive amounts are excreted in urine
§
○
Riboflavin Deficiency
Ariboflavinosis
Cells in tissues lining the throat, mouth, tongue, and lips
become inflamed or swollen
□
Sore throat, stomatitis, glossitis, cheilosis □
§
In elderly, reduced conversion of vitamin B6 to its active form
§
Altered iron metabolism and the synthesis of hemoglobin
§
○
-
Niacin (B3)
Two active forms derived from food
Nicotinic acid and nicotinamide
§
○
Converted to active coenzymes
Nicotinamide adenine dinucleotide (NAD+)
§
Nicotinamide adenine dinucleotide phosphate (NADP+)
§
○
Bioavailability
Less available in plant foods (wheat or corn)
§
More available in dairy foods and meat
§
○
Absorbed in the small intestine by simple diffusion
Circulates through the blood to the liver
§
○
Structures of Niacin and its Coenzyme Forms NAD+ and NAPD+
○
Metabolic Functions
Coenzyme in oxidation-reduction reactions
Glucose, protein, fat, and alcohol metabolism□
Folate and vitamin C metabolism□
§
Keeps skin cells healthy and digestive system functioning properly
§
In therapeutic doses:
Lowers total cholesterol in the blood by lowering Lp(a)
lipoprotein
□
Lowers triglycerides□
Raises HDL cholesterol □
§
Niacin Functions as NAD+ in Energy Metabolism
§
○
Daily Needs and Food Sources
Can be synthesized by the body from amino acid tryptophan
60 mg of tryptophan = 1 niacin equivalent (NE)□
Conversion requires riboflavin, vitamin B6, and iron□
§
Major food sources
Meats, fish, poultry□
Enriched and fortified grains and cereals□
Amino acid tryptophan □
§
Stable in foods
Not destroyed by hear or UV light□
Can leach if food is cooked or soaked in water□
§
○
Niacin Toxicity
No known cause except excess supplements or too many overly
fortified foods which can cause:
Reddish coloring of face, arms, and chest□
Nausea, vomiting□
Heartburn□
Liver toxicity□
Raised blood glucose levels□
§
○
Niacin Deficiency
Pellagra (disease of the 4 D's)
Dermatitis (drying of skin)□
Diarrhea□
Dementia□
Death□
§
○
-
Pantothenic Acid
Part of compound coenzyme A, which then used to make acetyl CoA
○
Sometimes referred to as B5
○
Absorption
In the small intestine
§
If intake is high: passive diffusion
§
If intake is low: active transport
§
○
Acetyl CoA is not stored, but high concentrations are found in the liver,
kidney, adrenal glands, and brain
○
Structures of Pantothenic Acid and Coenzyme A
○
Metabolic Functions
Part of coenzyme A used in fat, carb, and protein metabolism
Fat: synthesizes fatty acids and converts them to energy□
Carb: converts pyruvate to acetyl CoA□
Protein: converts amino acids to substrates in the TCA cycle□
§
Synthesis of:
Cholesterol □
Steroid hormones□
Neurotransmitter acetylcholine □
§
Pantothenic Acid and Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Widespread in a large variety of foods (so won't ask)□
Largest amount in:
Whole-grain cereals
®
Nuts and legumes, peanut butter
®
Meat, milk, and eggs
®
□
Can be destroyed by heat, so processed foods (canned
vegetables, fish, meat) are lowered than fresh foods
b/c found in like all foods, but b/c destroyed by heat,
better source is fresh foods that aren't processed
®
□
§
○
Pantothenic Acid Toxicity
No known toxicity
§
○
Pantothenic Acid Deficiency
Rare.
May experience:
Fatigue
®
Nausea
®
Vomiting
®
Numbness
®
Muscle cramps
®
Difficulty walking
®
□
§
○
-
Biotin
Made of sulfur-containing double rings and a side chain
○
Absorption
Biotinidase removes biotin from food
§
Active transport in the small intestine
§
Absorbed into the liver
§
○
Metabolic functions
Coenzyme for enzymes involved in energy metabolism (adds
oxygen)
Synthesis of fatty acids□
Replenishes oxaloacetate from pyruvate□
Amino acid metabolism□
§
DNA replication and transcription of genes
§
Cell development and growth
Maintenance of healthy hair and nails (referred to beauty
vitamin, see this on mastering)
□
§
The Role of Biotin as a Coenzyme in Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Peanuts*□
Yeast□
Liver and other organ meats□
Bacteria in the GI tract□
Egg yolks□
Whole grains□
Fish □
So note yes we do make it in our gut, but we don't know how
much
□
§
○
Biotin Toxicity
Rare
§
○
Biotin Deficiency
Seen with:
Overconsumption of raw egg whites (>12/ day for a
prolonged time); avidin in raw egg can bind to biotin and
cause deficiency symptoms
□
Total parenteral nutrition□
Impaired absorption□
Rare genetic disorders□
§
Symptoms include hair loss, depression, conjuctivitis, dermatitis,
lethargy, hallucinations
§
○
-
Vitamin B6
Collective name for several related compounds
○
Absorption
75% bioavailable
§
All forms absorbed in small intestine by passive diffusion
§
Bound to albumin and transported to the liver (where it is
activated)
§
○
Active form
Pyridoxal phosphate (PLP)
Stored mostly in the muscle, some in the liver (instead of
being excreted)
□
§
○
Metabolic Functions
Coenzyme for more than 100 enzymes
Most involved in protein metabolism□
§
Amino acid metabolism
PLP needed in transamination to form nonessential amino
acids
□
§
Carb metabolism
Glyconeolysis and gluconeogenesis□
§
Makes hemoglobin for red blood cells
§
Keeps immune and nervous systems healthy
§
May reduce risk for heart disease (help conversion of hemocysteine
to methionine like B12; not letting homocysteine build up)
§
Reduces nausea and vomiting
§
○
Daily Needs and Food Sources
Variety of food sources
Ready-to-eat cereals□
Meat, fish, poultry□
Fruits and vegetables□
Nuts and other legumes□
§
○
Vitamin B6 Toxicity
It attaches to enzymes in the muscle and other tissues and will
remain in the body. It can reach toxic levels, usually due to excess
intake of supplements
Nerve damage □
Difficulty walking□
Tingling in legs and feet□
§
Large doses do not cure carpal tunnel syndrome
§
○
Vitamin B6 Deficiency
Deficiency symptoms
Sore tongue□
Inflammation of the skin□
Depression□
confusion□
§
Microcytic hypochromic anemia
Red blood cells are small and pale□
§
Often caused by excessive alcohol consumption
§
○
-
Folate
Is found in many foods
○
Folic acid is the synthetic form added to foods and in supplements
○
Most folate in foods is in the polyglutamate form
○
Absorption
All but one glutamate is removed to form monoglutamate during
digestion
§
In the small intestine, 5-methyl-tetrahydrofolate is formed and
transported to the liver
§
○
Active form: tetrahydrofolate
○
Structure of Folate and its Coenzyme Form
○
Digestion of Folate
○
What is Folate?
Bioavailability
Folic acid is more bioavailable than folate□
Folate is destroyed w/ exposure to heat and light□
Raw foods have more folate than cooked foods□
Some foods contain enzymes that inhibit folate availability
Beans, legumes, and cabbage
®
□
§
○
Metabolic Functions
Transfers single-carbon compounds (ex. Methyl) to form new
compounds (ex. Through methylation to repair and/ or code for
DNA, which kind of goes to next point)
§
DNA and amino acid synthesis
§
Homocysteine metabolism
§
Assists in neural tube development to prevent:
Neural tube defects□
Anencephaly□
Spina bifida□
§
May prevent cancer and heart disease
§
○
Daily Needs
Dietary Folate Equivalents (DFE)
Unit used to define the RDA for folate □
Accounts for differences in absorption b/w synthetic folate
and folate in food
□
Synthetic folate acid if absorbed 1.7x more efficiently than
natural folate
□
§
○
Food Sources
Major food sources: think foliage (leaves)
Dark green leafy vegetables, legumes, and seeds□
Enriched pasta, rich, and cereals□
Liver □
§
○
Folate Toxicity
No risk from eating foods w/ folate
§
Excess intake from fortified food or supplements can mask a B12
deficiency
§
○
Folate Deficiency
Interferes w/ normal red blood cell division
§
Megaloblasts --> macrocytes --> macrocytic anemia
Red blood cells are abnormally large□
§
Macrocytic anemia
Symptoms
Fatigue
®
Weakness
®
Irritability
®
Shortness of breath
®
□
§
○
-
Vitamin B12
Also called cobalamin
○
Two forms
Both forms contain cobalt
§
○
Absorption
○
What is Vitamin 12 (cont'd)?
Stored mostly in liver
§
Excreted through the bile and urine
§
Deficiency can take years to develop
§
○
Metabolic Functions
Two enzymes (don't need to know)
Methylcobalamin: converts hemocysteine to methionine;
prevents homocysteine buildup
□
Deoxyadenosylcobalamin: helps form succinyl CoA during the
TCA cycle
□
§
Activates folate
§
Synthesis of new cells, especially red blood cells
§
Maintains myelin sheath of nerve tissue
§
Catabolism of amino acids and fatty acids for energy metabolism
§
○
Daily Needs
Bioavailability
Absorption decreases w/ age
Atropic gastritis:
Vitamin B12 is not released from the protein in
food
◊
Bacterial overgrowth reduces vitamin B12
absorption
◊
®
Absorption of the synthetic form is not hindered
®
Insufficient factor and gastric bypass can inhibit
absorption
®
□
Microwave cooking reduces the active form by 30-40%□
§
○
Food Sources
Grains*, meats, dairy
This is why vegans have an issue (see point below)□
§
○
Vitamin B12 Toxicity
No known risks
§
Absorption decreases w/ higher intakes
§
○
Vitamin B12 Deficiency
Causes
Low intake, as w/ vegan diets□
Malabsorption w/o adequate HCl□
Insufficient pancreatic enzymes, IF (intrinsic factor)□
Gastric bypass□
§
Symptoms
Macrocytic anemia
Due to folate deficiency
®
□
Pernicious anemia
B12 deficiency
®
Fatigue
®
Shortness of breath
®
Long-term consequence
Permanent nerve damage (tingling and numbness
in arms and legs)
◊
®
□
§
○
-
Vitamin C
Also known as ascorbic acid
○
Humans lack the enzyme to make vitamin C
○
Absorption
Small intestine by active transport
§
Higher intakes absorbed by simple diffusion in the stomach and
small intestine
§
Absorption decreases 50% w/ intakes > 1g ***
So don't take it in larger amounts b/c decrease bioavailability □
§
Excreted through kidneys
§
Not stored in the body
§
○
Metabolic Functions
Collagen synthesis
Occurs by hydroxylation reactions□
Always see it in night cream and anti-aging creams□
Also in research: in drinks/ gels/ jello concoctions for injured
athlets
□
§
Antioxidant
Reduces risk for heart disease and cancer□
Accepts or donates electrons to balance free radicals□
§
Iron absorption is enhanced **
Plant sources of nonheme iron□
§
○
Functions of Vitamin C
Helps to maintain the immune system
Promotes white blood cell synthesis □
§
May reduce the body's response to stress
When stressed, cortisol is released but also vitamin C so they
believe that may be released to balance levels?
□
§
Aids in the conversion of tryptophan and tyrosine to serotonin and
norepinephrine
§
Aids in the synthesis of thyroxine
§
Converts cholesterol to bile
§
Assists w/ histamine breakdown
§
○
Daily Needs and Food Sources
○
Vitamin C Toxicity
Consuming > 3,000 mg can cause nausea, stomach cramps, and
diarrhea
When popping airborne's and stuff when flu/ cold season,
when get upset stomach: vitamin C over-consumption/
toxicity
□
§
Overconsumption can lead to:
Kidney stones □
False positive or false negative medical tests□
§
Those w/ hemochromatosis (iron-loading disorder) should avoid
excess amounts
§
○
Vitamin C Deficiency
Scurvy
Bleeding gums□
Coiled or curly arm hairs□
Wounds won't heal□
Rough rash□
§
Prevented w/ 10 mg of vitamin C/ day
§
○
-
Other Vitamin-Like Compounds (WON'T BE TESTED ON)
Some compounds may not be classified as vitamins but are essential to
overall health
○
Often synthesized in adequate amounts in the body
○
May become essential under certain circumstances, such as during illness
or chronic disease
○
Include the following:
Choline
Not classified as a vitamin, though grouped w/ the B vitamins □
Major functions
Part of phospholipid that makes up the cell wall
®
Liver metabolism
®
Precursor to acetylcholine
®
Participated in nerve transmission
®
Assists in the transport of lipids
®
Fetal development
®
□
Can be synthesized by the body□
Major food sources
Animal sources: milk, liver, eggs
®
Peanuts
®
□
Toxicity □
Excess from supplements can cause sweating, vomiting,
hypotension, fishy odor
□
§
Carnitine, lipoic acid, and inositol can all be synthesized by the body
§
Carnitine
Needed to properly utilize fat□
Major food sources
Meat and dairy products
®
□
§
Lipoic acid
Helps cells generate energy□
Potential antioxidant effects□
§
Inositol
Keeps cell membranes healthy□
Found in plant sources□
§
○
-
Chpt. 10 Water-Soluble Vitamins
Friday, March 16, 2018
1:35 PM
There are nine water-soluble vitamins
Vitamin C
○
Eight B-complex vitamins
Initially thought to be one vitamin
§
Years of research uncovered it was several substances
Thiamin □
Riboflavin□
Niacin□
Vitamin B6□
Folate□
Vitamin B12□
Pantothenic acid□
Biotin□
§
○
Easily destroyed by heat, light, and oxidation
○
Traits of water-soluble vitamins vs fat-soluble vitamins
○
-
Digesting and Absorbing Water-Soluble Vitamins
-
Primary Functions of Water-Soluble Vitamins
B vitamins act as co-enzymes in many metabolic processes
Act as coenzymes to catalyze the enzyme to build or break apart
compounds
§
Transform carbs, proteins, and fats to ATP
Thiamin□
Riboflavin□
Niacin□
Pantothenic acid□
Biotin□
Vitamin B6□
§
B Vitamins Function as Coenzymes
§
Water-soluble vitamins in other critical roles:
Antioxidant: vitamin C□
Nerve function: thiamin□
Protein synthesis: niacin□
Formation of red blood cells: folate and vitamin B12□
Several B vitamins promote heart health
□
§
B Vitamins Function in Energy Metabolism
§
○
-
Thiamin (B1)
First B vitamin discovered
Casimir Funk identified thiamin as the curative factor in unpolished
rice in 1911
§
○
Dietary form converted to active coenzyme form thiamin pyrophosphate
(TPP)
○
It is destroyed in basic; acid solution protect it
○
Absorption
In jejunum by passive diffusion
§
Active transport is used w/ low intakes
§
Transported through the blood and excreted through urine
§
○
Structures of Thiamin and Thiamin Pyrophosphate
○
Metabolic Functions
Produces ATP from carbohydrate metabolism
TPP activates decarboxylase to remove a carbon from
pyruvate; forms acetyl CoA
□
TPP-dependent enzymes convert alpha-ketoglutarate to
succinyl CoA in the TCA cycle
□
§
Converts branched-chain amino acids to acetyl CoA
§
Makes pentoses used to synthesize DNA and RNA (so can't make
those w/o thiamin)
§
Transmission of nerve impulses (non-metabolic function)
§
The Function of Thiamin Pyrophosphate in Energy Metabolism
§
○
Daily Needs and Food Sources of Thiamin
Major food sources:
Enriched and fortified foods (remember these add back
vitamins b1, b2, and b3)
□
Whole-grain foods
□
Lean pork (ham and bacon)
□
§
○
Thiamin Toxicity
No known toxicity
§
○
Thiamin Deficiency
Berbiberi
Symptoms include loss of appetite, weight loss, confusion,
muscle weakness, peripheral neuropathy
□
Classifications
Wet: edema and congestive heart failure
®
Dry: muscle wasting w/o edema or nerve degeneration
®
□
§
Wernicke-Korsakoff syndrome
Caused by chronic alcohol abuse□
§
Causes of deficiency:
Inadequate dietary intake□
Malabsorption□
Alcoholism□
Prolonged diarrhea□
Times of increased need w/ too little intake
Pregnancy and lactation
®
□
§
○
-
Riboflavin (B2)
Composed of a side chain and ring structure
○
Two coenzyme forms
Flavin mononucleotide (FMN)
§
Flavin adenine dinucleotide (FAD)
§
○
Stable during cooking except in the presence of UV light
○
Absorption
Attached to proteins in food
§
Released in the presence of hydrochloric acid in the stomach
§
Absorbed by active transport in the small intestine
§
○
Structures of Riboflavin and the Coenzyme Forms of FAD and FMN
○
Metabolic Functions
Participates in energy metabolism through oxidation
FAD and FMN accept hydrogen ions (H+)□
FADH2 transports electrons to the electron transport chain to
make ATP
□
Participates in beta-oxidation□
Participates in oxidation-reduction reactions that protect cells
from oxidative stress
□
§
Enhances the function of other B vitamins
§
Role of FAD in the TCA Cycle
§
○
Daily Needs and Food Sources
Major food sources
Milk □
Yogurt□
Enriched and fortified cereals and grains□
§
○
Riboflavin Toxicity
None; excessive amounts are excreted in urine
§
○
Riboflavin Deficiency
Ariboflavinosis
Cells in tissues lining the throat, mouth, tongue, and lips
become inflamed or swollen
□
Sore throat, stomatitis, glossitis, cheilosis □
§
In elderly, reduced conversion of vitamin B6 to its active form
§
Altered iron metabolism and the synthesis of hemoglobin
§
○
-
Niacin (B3)
Two active forms derived from food
Nicotinic acid and nicotinamide
§
○
Converted to active coenzymes
Nicotinamide adenine dinucleotide (NAD+)
§
Nicotinamide adenine dinucleotide phosphate (NADP+)
§
○
Bioavailability
Less available in plant foods (wheat or corn)
§
More available in dairy foods and meat
§
○
Absorbed in the small intestine by simple diffusion
Circulates through the blood to the liver
§
○
Structures of Niacin and its Coenzyme Forms NAD+ and NAPD+
○
Metabolic Functions
Coenzyme in oxidation-reduction reactions
Glucose, protein, fat, and alcohol metabolism□
Folate and vitamin C metabolism□
§
Keeps skin cells healthy and digestive system functioning properly
§
In therapeutic doses:
Lowers total cholesterol in the blood by lowering Lp(a)
lipoprotein
□
Lowers triglycerides□
Raises HDL cholesterol □
§
Niacin Functions as NAD+ in Energy Metabolism
§
○
Daily Needs and Food Sources
Can be synthesized by the body from amino acid tryptophan
60 mg of tryptophan = 1 niacin equivalent (NE)□
Conversion requires riboflavin, vitamin B6, and iron□
§
Major food sources
Meats, fish, poultry□
Enriched and fortified grains and cereals□
Amino acid tryptophan □
§
Stable in foods
Not destroyed by hear or UV light□
Can leach if food is cooked or soaked in water□
§
○
Niacin Toxicity
No known cause except excess supplements or too many overly
fortified foods which can cause:
Reddish coloring of face, arms, and chest□
Nausea, vomiting□
Heartburn□
Liver toxicity□
Raised blood glucose levels□
§
○
Niacin Deficiency
Pellagra (disease of the 4 D's)
Dermatitis (drying of skin)□
Diarrhea□
Dementia□
Death□
§
○
-
Pantothenic Acid
Part of compound coenzyme A, which then used to make acetyl CoA
○
Sometimes referred to as B5
○
Absorption
In the small intestine
§
If intake is high: passive diffusion
§
If intake is low: active transport
§
○
Acetyl CoA is not stored, but high concentrations are found in the liver,
kidney, adrenal glands, and brain
○
Structures of Pantothenic Acid and Coenzyme A
○
Metabolic Functions
Part of coenzyme A used in fat, carb, and protein metabolism
Fat: synthesizes fatty acids and converts them to energy□
Carb: converts pyruvate to acetyl CoA□
Protein: converts amino acids to substrates in the TCA cycle□
§
Synthesis of:
Cholesterol □
Steroid hormones□
Neurotransmitter acetylcholine □
§
Pantothenic Acid and Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Widespread in a large variety of foods (so won't ask)□
Largest amount in:
Whole-grain cereals
®
Nuts and legumes, peanut butter
®
Meat, milk, and eggs
®
□
Can be destroyed by heat, so processed foods (canned
vegetables, fish, meat) are lowered than fresh foods
b/c found in like all foods, but b/c destroyed by heat,
better source is fresh foods that aren't processed
®
□
§
○
Pantothenic Acid Toxicity
No known toxicity
§
○
Pantothenic Acid Deficiency
Rare.
May experience:
Fatigue
®
Nausea
®
Vomiting
®
Numbness
®
Muscle cramps
®
Difficulty walking
®
□
§
○
-
Biotin
Made of sulfur-containing double rings and a side chain
○
Absorption
Biotinidase removes biotin from food
§
Active transport in the small intestine
§
Absorbed into the liver
§
○
Metabolic functions
Coenzyme for enzymes involved in energy metabolism (adds
oxygen)
Synthesis of fatty acids□
Replenishes oxaloacetate from pyruvate□
Amino acid metabolism□
§
DNA replication and transcription of genes
§
Cell development and growth
Maintenance of healthy hair and nails (referred to beauty
vitamin, see this on mastering)
□
§
The Role of Biotin as a Coenzyme in Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Peanuts*□
Yeast□
Liver and other organ meats□
Bacteria in the GI tract□
Egg yolks□
Whole grains□
Fish □
So note yes we do make it in our gut, but we don't know how
much
□
§
○
Biotin Toxicity
Rare
§
○
Biotin Deficiency
Seen with:
Overconsumption of raw egg whites (>12/ day for a
prolonged time); avidin in raw egg can bind to biotin and
cause deficiency symptoms
□
Total parenteral nutrition□
Impaired absorption□
Rare genetic disorders□
§
Symptoms include hair loss, depression, conjuctivitis, dermatitis,
lethargy, hallucinations
§
○
-
Vitamin B6
Collective name for several related compounds
○
Absorption
75% bioavailable
§
All forms absorbed in small intestine by passive diffusion
§
Bound to albumin and transported to the liver (where it is
activated)
§
○
Active form
Pyridoxal phosphate (PLP)
Stored mostly in the muscle, some in the liver (instead of
being excreted)
□
§
○
Metabolic Functions
Coenzyme for more than 100 enzymes
Most involved in protein metabolism□
§
Amino acid metabolism
PLP needed in transamination to form nonessential amino
acids
□
§
Carb metabolism
Glyconeolysis and gluconeogenesis□
§
Makes hemoglobin for red blood cells
§
Keeps immune and nervous systems healthy
§
May reduce risk for heart disease (help conversion of hemocysteine
to methionine like B12; not letting homocysteine build up)
§
Reduces nausea and vomiting
§
○
Daily Needs and Food Sources
Variety of food sources
Ready-to-eat cereals□
Meat, fish, poultry□
Fruits and vegetables□
Nuts and other legumes□
§
○
Vitamin B6 Toxicity
It attaches to enzymes in the muscle and other tissues and will
remain in the body. It can reach toxic levels, usually due to excess
intake of supplements
Nerve damage □
Difficulty walking□
Tingling in legs and feet□
§
Large doses do not cure carpal tunnel syndrome
§
○
Vitamin B6 Deficiency
Deficiency symptoms
Sore tongue□
Inflammation of the skin□
Depression□
confusion□
§
Microcytic hypochromic anemia
Red blood cells are small and pale□
§
Often caused by excessive alcohol consumption
§
○
-
Folate
Is found in many foods
○
Folic acid is the synthetic form added to foods and in supplements
○
Most folate in foods is in the polyglutamate form
○
Absorption
All but one glutamate is removed to form monoglutamate during
digestion
§
In the small intestine, 5-methyl-tetrahydrofolate is formed and
transported to the liver
§
○
Active form: tetrahydrofolate
○
Structure of Folate and its Coenzyme Form
○
Digestion of Folate
○
What is Folate?
Bioavailability
Folic acid is more bioavailable than folate□
Folate is destroyed w/ exposure to heat and light□
Raw foods have more folate than cooked foods□
Some foods contain enzymes that inhibit folate availability
Beans, legumes, and cabbage
®
□
§
○
Metabolic Functions
Transfers single-carbon compounds (ex. Methyl) to form new
compounds (ex. Through methylation to repair and/ or code for
DNA, which kind of goes to next point)
§
DNA and amino acid synthesis
§
Homocysteine metabolism
§
Assists in neural tube development to prevent:
Neural tube defects□
Anencephaly□
Spina bifida□
§
May prevent cancer and heart disease
§
○
Daily Needs
Dietary Folate Equivalents (DFE)
Unit used to define the RDA for folate □
Accounts for differences in absorption b/w synthetic folate
and folate in food
□
Synthetic folate acid if absorbed 1.7x more efficiently than
natural folate
□
§
○
Food Sources
Major food sources: think foliage (leaves)
Dark green leafy vegetables, legumes, and seeds□
Enriched pasta, rich, and cereals□
Liver □
§
○
Folate Toxicity
No risk from eating foods w/ folate
§
Excess intake from fortified food or supplements can mask a B12
deficiency
§
○
Folate Deficiency
Interferes w/ normal red blood cell division
§
Megaloblasts --> macrocytes --> macrocytic anemia
Red blood cells are abnormally large□
§
Macrocytic anemia
Symptoms
Fatigue
®
Weakness
®
Irritability
®
Shortness of breath
®
□
§
○
-
Vitamin B12
Also called cobalamin
○
Two forms
Both forms contain cobalt
§
○
Absorption
○
What is Vitamin 12 (cont'd)?
Stored mostly in liver
§
Excreted through the bile and urine
§
Deficiency can take years to develop
§
○
Metabolic Functions
Two enzymes (don't need to know)
Methylcobalamin: converts hemocysteine to methionine;
prevents homocysteine buildup
□
Deoxyadenosylcobalamin: helps form succinyl CoA during the
TCA cycle
□
§
Activates folate
§
Synthesis of new cells, especially red blood cells
§
Maintains myelin sheath of nerve tissue
§
Catabolism of amino acids and fatty acids for energy metabolism
§
○
Daily Needs
Bioavailability
Absorption decreases w/ age
Atropic gastritis:
Vitamin B12 is not released from the protein in
food
◊
Bacterial overgrowth reduces vitamin B12
absorption
◊
®
Absorption of the synthetic form is not hindered
®
Insufficient factor and gastric bypass can inhibit
absorption
®
□
Microwave cooking reduces the active form by 30-40%□
§
○
Food Sources
Grains*, meats, dairy
This is why vegans have an issue (see point below)□
§
○
Vitamin B12 Toxicity
No known risks
§
Absorption decreases w/ higher intakes
§
○
Vitamin B12 Deficiency
Causes
Low intake, as w/ vegan diets□
Malabsorption w/o adequate HCl□
Insufficient pancreatic enzymes, IF (intrinsic factor)□
Gastric bypass□
§
Symptoms
Macrocytic anemia
Due to folate deficiency
®
□
Pernicious anemia
B12 deficiency
®
Fatigue
®
Shortness of breath
®
Long-term consequence
Permanent nerve damage (tingling and numbness
in arms and legs)
◊
®
□
§
○
-
Vitamin C
Also known as ascorbic acid
○
Humans lack the enzyme to make vitamin C
○
Absorption
Small intestine by active transport
§
Higher intakes absorbed by simple diffusion in the stomach and
small intestine
§
Absorption decreases 50% w/ intakes > 1g ***
So don't take it in larger amounts b/c decrease bioavailability □
§
Excreted through kidneys
§
Not stored in the body
§
○
Metabolic Functions
Collagen synthesis
Occurs by hydroxylation reactions□
Always see it in night cream and anti-aging creams□
Also in research: in drinks/ gels/ jello concoctions for injured
athlets
□
§
Antioxidant
Reduces risk for heart disease and cancer□
Accepts or donates electrons to balance free radicals□
§
Iron absorption is enhanced **
Plant sources of nonheme iron□
§
○
Functions of Vitamin C
Helps to maintain the immune system
Promotes white blood cell synthesis □
§
May reduce the body's response to stress
When stressed, cortisol is released but also vitamin C so they
believe that may be released to balance levels?
□
§
Aids in the conversion of tryptophan and tyrosine to serotonin and
norepinephrine
§
Aids in the synthesis of thyroxine
§
Converts cholesterol to bile
§
Assists w/ histamine breakdown
§
○
Daily Needs and Food Sources
○
Vitamin C Toxicity
Consuming > 3,000 mg can cause nausea, stomach cramps, and
diarrhea
When popping airborne's and stuff when flu/ cold season,
when get upset stomach: vitamin C over-consumption/
toxicity
□
§
Overconsumption can lead to:
Kidney stones □
False positive or false negative medical tests□
§
Those w/ hemochromatosis (iron-loading disorder) should avoid
excess amounts
§
○
Vitamin C Deficiency
Scurvy
Bleeding gums□
Coiled or curly arm hairs□
Wounds won't heal□
Rough rash□
§
Prevented w/ 10 mg of vitamin C/ day
§
○
-
Other Vitamin-Like Compounds (WON'T BE TESTED ON)
Some compounds may not be classified as vitamins but are essential to
overall health
○
Often synthesized in adequate amounts in the body
○
May become essential under certain circumstances, such as during illness
or chronic disease
○
Include the following:
Choline
Not classified as a vitamin, though grouped w/ the B vitamins □
Major functions
Part of phospholipid that makes up the cell wall
®
Liver metabolism
®
Precursor to acetylcholine
®
Participated in nerve transmission
®
Assists in the transport of lipids
®
Fetal development
®
□
Can be synthesized by the body□
Major food sources
Animal sources: milk, liver, eggs
®
Peanuts
®
□
Toxicity □
Excess from supplements can cause sweating, vomiting,
hypotension, fishy odor
□
§
Carnitine, lipoic acid, and inositol can all be synthesized by the body
§
Carnitine
Needed to properly utilize fat□
Major food sources
Meat and dairy products
®
□
§
Lipoic acid
Helps cells generate energy□
Potential antioxidant effects□
§
Inositol
Keeps cell membranes healthy□
Found in plant sources□
§
○
-
Chpt. 10 Water-Soluble Vitamins
Friday, March 16, 2018 1:35 PM
There are nine water-soluble vitamins
Vitamin C
○
Eight B-complex vitamins
Initially thought to be one vitamin
§
Years of research uncovered it was several substances
Thiamin □
Riboflavin□
Niacin□
Vitamin B6□
Folate□
Vitamin B12□
Pantothenic acid□
Biotin□
§
○
Easily destroyed by heat, light, and oxidation
○
Traits of water-soluble vitamins vs fat-soluble vitamins
○
-
Digesting and Absorbing Water-Soluble Vitamins
-
Primary Functions of Water-Soluble Vitamins
B vitamins act as co-enzymes in many metabolic processes
Act as coenzymes to catalyze the enzyme to build or break apart
compounds
§
Transform carbs, proteins, and fats to ATP
Thiamin□
Riboflavin□
Niacin□
Pantothenic acid□
Biotin□
Vitamin B6□
§
B Vitamins Function as Coenzymes
§
Water-soluble vitamins in other critical roles:
Antioxidant: vitamin C□
Nerve function: thiamin□
Protein synthesis: niacin□
Formation of red blood cells: folate and vitamin B12□
Several B vitamins promote heart health□
§
B Vitamins Function in Energy Metabolism
§
○
-
Thiamin (B1)
First B vitamin discovered
Casimir Funk identified thiamin as the curative factor in unpolished
rice in 1911
§
○
Dietary form converted to active coenzyme form thiamin pyrophosphate
(TPP)
○
It is destroyed in basic; acid solution protect it
○
Absorption
In jejunum by passive diffusion
§
Active transport is used w/ low intakes
§
Transported through the blood and excreted through urine
§
○
Structures of Thiamin and Thiamin Pyrophosphate
○
Metabolic Functions
Produces ATP from carbohydrate metabolism
TPP activates decarboxylase to remove a carbon from
pyruvate; forms acetyl CoA
□
TPP-dependent enzymes convert alpha-ketoglutarate to
succinyl CoA in the TCA cycle
□
§
Converts branched-chain amino acids to acetyl CoA
§
Makes pentoses used to synthesize DNA and RNA (so can't make
those w/o thiamin)
§
Transmission of nerve impulses (non-metabolic function)
§
The Function of Thiamin Pyrophosphate in Energy Metabolism
§
○
Daily Needs and Food Sources of Thiamin
Major food sources:
Enriched and fortified foods (remember these add back
vitamins b1, b2, and b3)
□
Whole-grain foods□
Lean pork (ham and bacon)□
§
○
Thiamin Toxicity
No known toxicity
§
○
Thiamin Deficiency
Berbiberi
Symptoms include loss of appetite, weight loss, confusion,
muscle weakness, peripheral neuropathy
□
Classifications
Wet: edema and congestive heart failure
®
Dry: muscle wasting w/o edema or nerve degeneration
®
□
§
Wernicke-Korsakoff syndrome
Caused by chronic alcohol abuse
□
§
Causes of deficiency:
Inadequate dietary intake
□
Malabsorption
□
Alcoholism
□
Prolonged diarrhea
□
Times of increased need w/ too little intake
Pregnancy and lactation
®
□
§
○
-
Riboflavin (B2)
Composed of a side chain and ring structure
○
Two coenzyme forms
Flavin mononucleotide (FMN)
§
Flavin adenine dinucleotide (FAD)
§
○
Stable during cooking except in the presence of UV light
○
Absorption
Attached to proteins in food
§
Released in the presence of hydrochloric acid in the stomach
§
Absorbed by active transport in the small intestine
§
○
Structures of Riboflavin and the Coenzyme Forms of FAD and FMN
○
Metabolic Functions
Participates in energy metabolism through oxidation
FAD and FMN accept hydrogen ions (H+)
□
FADH2 transports electrons to the electron transport chain to
make ATP
□
Participates in beta-oxidation
□
Participates in oxidation-reduction reactions that protect cells
from oxidative stress
□
§
Enhances the function of other B vitamins
§
Role of FAD in the TCA Cycle
§
○
Daily Needs and Food Sources
Major food sources
Milk
□
Yogurt
□
Enriched and fortified cereals and grains
□
§
○
Riboflavin Toxicity
None; excessive amounts are excreted in urine
§
○
Riboflavin Deficiency
Ariboflavinosis
Cells in tissues lining the throat, mouth, tongue, and lips
become inflamed or swollen
□
Sore throat, stomatitis, glossitis, cheilosis □
§
In elderly, reduced conversion of vitamin B6 to its active form
§
Altered iron metabolism and the synthesis of hemoglobin
§
○
-
Niacin (B3)
Two active forms derived from food
Nicotinic acid and nicotinamide
§
○
Converted to active coenzymes
Nicotinamide adenine dinucleotide (NAD+)
§
Nicotinamide adenine dinucleotide phosphate (NADP+)
§
○
Bioavailability
Less available in plant foods (wheat or corn)
§
More available in dairy foods and meat
§
○
Absorbed in the small intestine by simple diffusion
Circulates through the blood to the liver
§
○
Structures of Niacin and its Coenzyme Forms NAD+ and NAPD+
○
Metabolic Functions
Coenzyme in oxidation-reduction reactions
Glucose, protein, fat, and alcohol metabolism□
Folate and vitamin C metabolism□
§
Keeps skin cells healthy and digestive system functioning properly
§
In therapeutic doses:
Lowers total cholesterol in the blood by lowering Lp(a)
lipoprotein
□
Lowers triglycerides□
Raises HDL cholesterol □
§
Niacin Functions as NAD+ in Energy Metabolism
§
○
Daily Needs and Food Sources
Can be synthesized by the body from amino acid tryptophan
60 mg of tryptophan = 1 niacin equivalent (NE)□
Conversion requires riboflavin, vitamin B6, and iron□
§
Major food sources
Meats, fish, poultry□
Enriched and fortified grains and cereals□
Amino acid tryptophan □
§
Stable in foods
Not destroyed by hear or UV light□
Can leach if food is cooked or soaked in water□
§
○
Niacin Toxicity
No known cause except excess supplements or too many overly
fortified foods which can cause:
Reddish coloring of face, arms, and chest□
Nausea, vomiting□
Heartburn□
Liver toxicity□
Raised blood glucose levels□
§
○
Niacin Deficiency
Pellagra (disease of the 4 D's)
Dermatitis (drying of skin)□
Diarrhea□
Dementia□
Death□
§
○
-
Pantothenic Acid
Part of compound coenzyme A, which then used to make acetyl CoA
○
Sometimes referred to as B5
○
Absorption
In the small intestine
§
If intake is high: passive diffusion
§
If intake is low: active transport
§
○
Acetyl CoA is not stored, but high concentrations are found in the liver,
kidney, adrenal glands, and brain
○
Structures of Pantothenic Acid and Coenzyme A
○
Metabolic Functions
Part of coenzyme A used in fat, carb, and protein metabolism
Fat: synthesizes fatty acids and converts them to energy□
Carb: converts pyruvate to acetyl CoA□
Protein: converts amino acids to substrates in the TCA cycle□
§
Synthesis of:
Cholesterol □
Steroid hormones□
Neurotransmitter acetylcholine □
§
Pantothenic Acid and Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Widespread in a large variety of foods (so won't ask)□
Largest amount in:
Whole-grain cereals
®
Nuts and legumes, peanut butter
®
Meat, milk, and eggs
®
□
Can be destroyed by heat, so processed foods (canned
vegetables, fish, meat) are lowered than fresh foods
b/c found in like all foods, but b/c destroyed by heat,
better source is fresh foods that aren't processed
®
□
§
○
Pantothenic Acid Toxicity
No known toxicity
§
○
Pantothenic Acid Deficiency
Rare.
May experience:
Fatigue
®
Nausea
®
Vomiting
®
Numbness
®
Muscle cramps
®
Difficulty walking
®
□
§
○
-
Biotin
Made of sulfur-containing double rings and a side chain
○
Absorption
Biotinidase removes biotin from food
§
Active transport in the small intestine
§
Absorbed into the liver
§
○
Metabolic functions
Coenzyme for enzymes involved in energy metabolism (adds
oxygen)
Synthesis of fatty acids□
Replenishes oxaloacetate from pyruvate□
Amino acid metabolism□
§
DNA replication and transcription of genes
§
Cell development and growth
Maintenance of healthy hair and nails (referred to beauty
vitamin, see this on mastering)
□
§
The Role of Biotin as a Coenzyme in Energy Metabolism
§
○
Daily Needs and Food Sources
Major food sources
Peanuts*□
Yeast□
Liver and other organ meats□
Bacteria in the GI tract□
Egg yolks□
Whole grains□
Fish □
So note yes we do make it in our gut, but we don't know how
much
□
§
○
Biotin Toxicity
Rare
§
○
Biotin Deficiency
Seen with:
Overconsumption of raw egg whites (>12/ day for a
prolonged time); avidin in raw egg can bind to biotin and
cause deficiency symptoms
□
Total parenteral nutrition□
Impaired absorption□
Rare genetic disorders□
§
Symptoms include hair loss, depression, conjuctivitis, dermatitis,
lethargy, hallucinations
§
○
-
Vitamin B6
Collective name for several related compounds
○
Absorption
75% bioavailable
§
All forms absorbed in small intestine by passive diffusion
§
Bound to albumin and transported to the liver (where it is
activated)
§
○
Active form
Pyridoxal phosphate (PLP)
Stored mostly in the muscle, some in the liver (instead of
being excreted)
□
§
○
Metabolic Functions
Coenzyme for more than 100 enzymes
Most involved in protein metabolism□
§
Amino acid metabolism
PLP needed in transamination to form nonessential amino
acids
□
§
Carb metabolism
Glyconeolysis and gluconeogenesis□
§
Makes hemoglobin for red blood cells
§
Keeps immune and nervous systems healthy
§
May reduce risk for heart disease (help conversion of hemocysteine
to methionine like B12; not letting homocysteine build up)
§
Reduces nausea and vomiting
§
○
Daily Needs and Food Sources
Variety of food sources
Ready-to-eat cereals□
Meat, fish, poultry□
Fruits and vegetables□
Nuts and other legumes□
§
○
Vitamin B6 Toxicity
It attaches to enzymes in the muscle and other tissues and will
remain in the body. It can reach toxic levels, usually due to excess
intake of supplements
Nerve damage □
Difficulty walking□
Tingling in legs and feet□
§
Large doses do not cure carpal tunnel syndrome
§
○
Vitamin B6 Deficiency
Deficiency symptoms
Sore tongue□
Inflammation of the skin□
Depression□
confusion□
§
Microcytic hypochromic anemia
Red blood cells are small and pale□
§
Often caused by excessive alcohol consumption
§
○
-
Folate
Is found in many foods
○
Folic acid is the synthetic form added to foods and in supplements
○
Most folate in foods is in the polyglutamate form
○
Absorption
All but one glutamate is removed to form monoglutamate during
digestion
§
In the small intestine, 5-methyl-tetrahydrofolate is formed and
transported to the liver
§
○
Active form: tetrahydrofolate
○
Structure of Folate and its Coenzyme Form
○
Digestion of Folate
○
What is Folate?
Bioavailability
Folic acid is more bioavailable than folate□
Folate is destroyed w/ exposure to heat and light□
Raw foods have more folate than cooked foods□
Some foods contain enzymes that inhibit folate availability
Beans, legumes, and cabbage
®
□
§
○
Metabolic Functions
Transfers single-carbon compounds (ex. Methyl) to form new
compounds (ex. Through methylation to repair and/ or code for
DNA, which kind of goes to next point)
§
DNA and amino acid synthesis
§
Homocysteine metabolism
§
Assists in neural tube development to prevent:
Neural tube defects□
Anencephaly□
Spina bifida□
§
May prevent cancer and heart disease
§
○
Daily Needs
Dietary Folate Equivalents (DFE)
Unit used to define the RDA for folate □
Accounts for differences in absorption b/w synthetic folate
and folate in food
□
Synthetic folate acid if absorbed 1.7x more efficiently than
natural folate
□
§
○
Food Sources
Major food sources: think foliage (leaves)
Dark green leafy vegetables, legumes, and seeds□
Enriched pasta, rich, and cereals□
Liver □
§
○
Folate Toxicity
No risk from eating foods w/ folate
§
Excess intake from fortified food or supplements can mask a B12
deficiency
§
○
Folate Deficiency
Interferes w/ normal red blood cell division
§
Megaloblasts --> macrocytes --> macrocytic anemia
Red blood cells are abnormally large□
§
Macrocytic anemia
Symptoms
Fatigue
®
Weakness
®
Irritability
®
Shortness of breath
®
□
§
○
-
Vitamin B12
Also called cobalamin
○
Two forms
Both forms contain cobalt
§
○
Absorption
○
What is Vitamin 12 (cont'd)?
Stored mostly in liver
§
Excreted through the bile and urine
§
Deficiency can take years to develop
§
○
Metabolic Functions
Two enzymes (don't need to know)
Methylcobalamin: converts hemocysteine to methionine;
prevents homocysteine buildup
□
Deoxyadenosylcobalamin: helps form succinyl CoA during the
TCA cycle
□
§
Activates folate
§
Synthesis of new cells, especially red blood cells
§
Maintains myelin sheath of nerve tissue
§
Catabolism of amino acids and fatty acids for energy metabolism
§
○
Daily Needs
Bioavailability
Absorption decreases w/ age
Atropic gastritis:
Vitamin B12 is not released from the protein in
food
◊
Bacterial overgrowth reduces vitamin B12
absorption
◊
®
Absorption of the synthetic form is not hindered
®
Insufficient factor and gastric bypass can inhibit
absorption
®
□
Microwave cooking reduces the active form by 30-40%□
§
○
Food Sources
Grains*, meats, dairy
This is why vegans have an issue (see point below)□
§
○
Vitamin B12 Toxicity
No known risks
§
Absorption decreases w/ higher intakes
§
○
Vitamin B12 Deficiency
Causes
Low intake, as w/ vegan diets□
Malabsorption w/o adequate HCl□
Insufficient pancreatic enzymes, IF (intrinsic factor)□
Gastric bypass□
§
Symptoms
Macrocytic anemia
Due to folate deficiency
®
□
Pernicious anemia
B12 deficiency
®
Fatigue
®
Shortness of breath
®
Long-term consequence
Permanent nerve damage (tingling and numbness
in arms and legs)
◊
®
□
§
○
-
Vitamin C
Also known as ascorbic acid
○
Humans lack the enzyme to make vitamin C
○
Absorption
Small intestine by active transport
§
Higher intakes absorbed by simple diffusion in the stomach and
small intestine
§
Absorption decreases 50% w/ intakes > 1g ***
So don't take it in larger amounts b/c decrease bioavailability □
§
Excreted through kidneys
§
Not stored in the body
§
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Metabolic Functions
Collagen synthesis
Occurs by hydroxylation reactions□
Always see it in night cream and anti-aging creams□
Also in research: in drinks/ gels/ jello concoctions for injured
athlets
□
§
Antioxidant
Reduces risk for heart disease and cancer□
Accepts or donates electrons to balance free radicals□
§
Iron absorption is enhanced **
Plant sources of nonheme iron□
§
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Functions of Vitamin C
Helps to maintain the immune system
Promotes white blood cell synthesis □
§
May reduce the body's response to stress
When stressed, cortisol is released but also vitamin C so they
believe that may be released to balance levels?
□
§
Aids in the conversion of tryptophan and tyrosine to serotonin and
norepinephrine
§
Aids in the synthesis of thyroxine
§
Converts cholesterol to bile
§
Assists w/ histamine breakdown
§
○
Daily Needs and Food Sources
○
Vitamin C Toxicity
Consuming > 3,000 mg can cause nausea, stomach cramps, and
diarrhea
When popping airborne's and stuff when flu/ cold season,
when get upset stomach: vitamin C over-consumption/
toxicity
□
§
Overconsumption can lead to:
Kidney stones □
False positive or false negative medical tests□
§
Those w/ hemochromatosis (iron-loading disorder) should avoid
excess amounts
§
○
Vitamin C Deficiency
Scurvy
Bleeding gums□
Coiled or curly arm hairs□
Wounds won't heal□
Rough rash□
§
Prevented w/ 10 mg of vitamin C/ day
§
○
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Other Vitamin-Like Compounds (WON'T BE TESTED ON)
Some compounds may not be classified as vitamins but are essential to
overall health
○
Often synthesized in adequate amounts in the body
○
May become essential under certain circumstances, such as during illness
or chronic disease
○
Include the following:
Choline
Not classified as a vitamin, though grouped w/ the B vitamins □
Major functions
Part of phospholipid that makes up the cell wall
®
Liver metabolism
®
Precursor to acetylcholine
®
Participated in nerve transmission
®
Assists in the transport of lipids
®
Fetal development
®
□
Can be synthesized by the body□
Major food sources
Animal sources: milk, liver, eggs
®
Peanuts
®
□
Toxicity □
Excess from supplements can cause sweating, vomiting,
hypotension, fishy odor
□
§
Carnitine, lipoic acid, and inositol can all be synthesized by the body
§
Carnitine
Needed to properly utilize fat□
Major food sources
Meat and dairy products
®
□
§
Lipoic acid
Helps cells generate energy□
Potential antioxidant effects□
§
Inositol
Keeps cell membranes healthy□
Found in plant sources□
§
○
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Chpt. 10 Water-Soluble Vitamins
Friday, March 16, 2018 1:35 PM
Document Summary
Years of research uncovered it was several substances. B vitamins act as co-enzymes in many metabolic processes. Act as coenzymes to catalyze the enzyme to build or break apart compounds. Formation of red blood cells: folate and vitamin b12. Casimir funk identified thiamin as the curative factor in unpolished rice in 1911. Dietary form converted to active coenzyme form thiamin pyrophosphate (tpp) It is destroyed in basic; acid solution protect it. Transported through the blood and excreted through urine. Tpp activates decarboxylase to remove a carbon from pyruvate; forms acetyl coa. Tpp-dependent enzymes convert alpha-ketoglutarate to succinyl coa in the tca cycle. Makes pentoses used to synthesize dna and rna (so can"t make those w/o thiamin) The function of thiamin pyrophosphate in energy metabolism. Enriched and fortified foods (remember these add back vitamins b1, b2, and b3) Symptoms include loss of appetite, weight loss, confusion, muscle weakness, peripheral neuropathy. Dry: muscle wasting w/o edema or nerve degeneration.
