Water-Soluble Vitamins
9 Water-soluble vitamins = 8B’s and 1C!
B1 = Thiamin
B2 = Riboflavin
B3 = Niacin
B5 = Pantothenic Acid
B6 = Pyridoxine
B7 = Biotin
B9 = Folate
B12 = Cobalamin
Easily destroyed by heat, light, and oxidation
Digestion
and
Absorption
Primary Functions
B vitamins act as coenzymes!
Coenzymes are a vital part of some enzymes, so
vitamins are needed for enzyme to work properly
These Transform carbohydrates, proteins, and fats to ATP
• Thiamin
• Riboflavin
• Niacin
• Pyridoxine
• Pantothenic Acid
• Biotin
B Vitamins
Function as
Coenzymes
Primary Functions
• Energy Metabolism: B Vitamins
– Antioxidant: Vitamin C
– Nerve Function: Thiamin
– Protein Synthesis: Niacin
– Formation of Red Blood Cells: Folate and Cobalamin
– Heart Health Promoted by Several B vitamins
B Vitamins
Function in
Energy
Metabolism
Thiamin (B1)
First B vit - *Missing nutrient in unpolished rice.
Destroyed in basic solutions; acid solutions protect it.
Absorbed - in jejunum (passive diffusion) and active
transport if low intakes
Produces ATP from Carbohydrate Metabolism
– TPP activates decarboxylase to form acetyl CoA.
– Convert α-ketoglutarate to succinyl CoA TCA cycle.
• Converts branched-chain AA’s to acetyl CoA
• Makes pentoses used to synthesize DNA and RNA
Thiamin and Thiamin Pyrophosphate (TPP)
TPP in Energy Metabolism
Thiamin Daily Needs & Food Sources
RDA Adults: Males: 1.2mg/day; Females: 1.1mg/day
Food
Source
Asparagus
Sunflower Seeds
Green Peas
Flaxseeds
Brussels Sprouts
Navy Beans
Black Beans
Barley
Dried Peas
Lentils
Pinto Beans
Lima Beans
Oats
Sesame Seeds
Kidney Beans
Tuna
Pineapple
Serving
Size
1 cup
¼ cup
1 cup
2 Tbs
1 cup
1 cup
1 cup
¼ cup
1 cup
1 cup
1 cup
1 cup
¼ cup
¼ cup
1 cup
4 oz
1 cup
Amount
(mg)
0.29
0.52
0.36
0.23
0.17
0.43
0.42
0.40
0.37
0.33
0.33
0.30
0.30
0.28
0.28
0.15
0.13
DRI/DV
(%)
24
43
30
19
14
36
35
33
31
28
28
25
25
23
23
13
11
Nutrient
Density
11.0
3.8
4.7
4.6
4.5
2.5
2.8
2.8
2.4
2.2
2.0
2.1
3.0
2.0
1.9
1.5
2.4
Thiamin Deficiency
No known Toxicity but Deficiency is Bad!!!
Beri Beri
Wasting (wt loss), impaired sensory perception, confusion,
derangement, muscle weakness, peripheral neuropathy nerve degeneration, arythmia.
Classifications:
1) Dry: Peripheral nerve damage, wasting without edema.
Psychological disorders.
2) Wet: Edema and congestive heart failure.
3) Infantile: From infancy thiamine deficiency.
Wernicke-Korsakoff Syndrome
Caused by chronic alcohol abuse depleting thiamin
Thiamin Insufficiency
↓ACh, Glutamate and GABA
All of these act as
neurotransmitters, therefore
Decrease in these act to
depress transmission of
nerve impulses!
GABA in Foods!
Riboflavin (B2)
Two Coenzyme forms
– Flavin mononucleotide (FMN)
– Flavin adenine dinucleotide (FAD)
Heat Stable (cooking) except in UV light
Absorption - Attached to proteins in food
Released in with HCl in stomach
Absorbed by active transport in small intestine
Structures of Riboflavin, FAD and FMN
Food
Sources
Involved in E Metabolism Via Oxidation
FAD and FMN accept hydrogen ions (H+)
FADH2 transports e-s to e- Transport Chain (ETC) makes ATP
Metabolic Functions of Riboflavin
– Participates in beta-oxidation (Fat Metabolism)
– Protects cells from oxidative stress
Enhances the function of other B vitamins
Riboflavin Daily Needs
RDA Adults:
Males: 1.3 mg/day;
Females: 1.1 mg/day
The Role of FAD in the TCA Cycle
Riboflavin Deficiency
No Toxicity
Deficiency
Ariboflavinosis – inflammation of tissues lining
the throat, mouth, tongue, and lips become.
Sore throat, stomatitis, glossitis, cheilosis*
Reduced conversion of B6 to its active form
Altered iron metabolism & syn of Hb (RBCs)
*Fissuring and dry scaling of lips and angles of the mouth
Niacin (B3)
2 Active Forms from food:
Nicotinic Acid and Nicotinamide
• Converted to Coenzymes
– Nicotinamide adenine dinucleotide (NAD+)
– Nicotinamide adenine dinucleotide phosphate (NADP+)
• Bioavailability
– Less available in plant foods (wheat grains).
– More available in dairy foods and meat.
• Absorbed - small intestine, simple diffusion.
Niacin is also involved in breaking down alcohol in the
body and in the synthesis of fatty acids.
Niacin and Coenzymes NAD+ and NADP+
Metabolic Functions of Niacin
• Coenzyme in oxidation-reduction reactions
– Glucose, protein, fat, and alcohol metabolism
– Folate and vitamin C Metabolism
• Keeps skin cells healthy and GI tract functioning
• In therapeutic doses:
– Lowers total cholesterol in the blood
– Lowers triglycerides
– Raises HDL cholesterol
+
NAD
in Energy Metabolism
Daily Needs for Niacin
RDA Adults: Males: 16 mg/day; Females: 14 mg/day
UL: 35 mg/day
• Synthesized in body from Tryptophan
– 60 mg of tryptophan = 1 niacin equivalent (NE)
– This requires riboflavin, vitamin B6, and iron
Niacin
Food Sources - Meats, fish, poultry & tryptophan
Heat and UV light Stable in Foods
• No Toxicity - from food intake!
• Excess supplements (and overly fortified foods):
•
•
•
•
•
Reddish coloring of the face, arms, and chest
Nausea, vomiting
Heartburn
Liver toxicity
Raised blood glucose levels
Niacin Deficiency
Pellagra
(disease of the 4 Ds)
•
•
•
•
Dermatitis
Diarrhea
Dementia
Death
Pantothenic Acid (B5)
• Part of Coenzyme A, then makes acetyl CoA
• Absorption - small intestine
– If intake is high: Passive diffusion
– If intake is low: Active transport
Not stored but high conc found in:
• Liver
• Kidney
• Adrenal glands
• Brain
Pantothenic Acid and Energy Metabolism
Metabolic Functions of Pantothenic Acid
Used in fat, carbohydrate, and protein Metabolism.
– Fat: makes FA’s and converts them to E
– Carbohydrate: Converts pyruvate to acetyl CoA
– Protein: Converts AA’s substrates in TCA cycle
Important in Synthesis of:
– Cholesterol
– Steroid Hormones
– Neurotransmitter Acetylcholine (ACh)
Pantothenic Acid Daily Needs and Food Sources
Male and female adults: 5 mg/day
• Major Food Sources
Widespread in a large variety - Eggs, fresh
vegetables, wheat bran, yeast, meat, milk…
Destroyed by Heat!
Processed foods (canned
vegetables, fish, meat)
are lower than fresh
foods in B5.
Pantothenic Acid Deficiency
No Toxicity
• Deficiency: Rare
Symptoms:
• Fatigue
• Nausea
• Vomiting
• Numbness
• Muscle cramps
• Difficulty walking
Pyridoxine (B6)
Vitamin B6
Absorption – 75% is Bioavailable (small intestine)
By passive diffusion
Bound to albumin and transported to liver
Stored mostly
in the muscle,
some in the liver
Metabolic Functions of Vitamin B6
• Coenzyme for more than 100 enzymes!
• Mostly Protein Metabolism and AA Metabolism
• Req in Transamination of non-essential AAs
Involved in:
Glycogenolysis and Gluconeogenesis
• Makes hemoglobin for RBCs
• Assist immune and nervous systems
• Reduce risk for Heart Disease
• Reduces Nausea and Vomiting
B6 Daily Needs and Food Sources
RDA Adults Males: 1.3 - 1.7 mg/day; Females: 1.3 - 1.5 mg/day
UL: 100 mg/day
Wide Variety
of Food Sources
Meat, fish, poultry
Fruits and Vegetables
Nuts and Legumes
Vitamin B6 Toxicity and Deficiency
Toxicity – from excess supplement intake. It attaches to enzymes
in muscle and other tissue & remains in body.
B6 Deficiency Symptoms
– Sore Tongue
– Inflammation of the skin
– Depression
– Confusion
Microcytic Hypochromic Anemia
Red blood cells are small and pale.
Excessive alcohol consumption depletes B6
Biotin (B7)
• Contains Sulfur (S)!
• Absorption - Biotinidase removes biotin from food.
– Active transport in Small Intestine
– Absorbed in the liver
Metabolic Functions of Biotin
• Coenzyme for E Metabolism
– Synthesis of Fatty Acids
– Amino Acid Metabolism
– Replenishes oxaloacetate from pyruvate
• DNA replication and transcription of genes
• Cell develp & growth - Healthy Hair and Nails
Biotin (B7)
Biotin Daily Needs and Food Sources
• Adults: Males and females: 30 μg/day;
Major Food Sources
– Yeast
– Liver and other organ meats
– Bacteria in the GI tract
– Egg yolks
– Whole grains
– Fish
– Many Nuts
Biotin Toxicity and Deficiency
• Toxicity: Very Rare
Deficiency:
• Can be from eating too many raw egg whites. The
Avidin in it binds biotin => deficiency symptoms
• Total parenteral nutrition
• Impaired absorption
• Rare genetic disorders
Symptoms:
Hair loss, depression, conjunctivitis, dermatitis,
lethargy, hallucinations
Folate B9
• Folate - the Natural Form of B9 in foods
• Folic Acid - synthetic form
(added to foods and in supplements)
• Extremely important to have optimal Folate during
pregnancy.
• Most folate in foods = Polyglutamate form.
• Absorption – only one glutamate kept during
digestion in small intestine
• Active form: Tetrahydrofolate - transported to liver.
Folate
Folic acid is more bioavailable than folate.
Folate destroyed with Heat and Light exposure.
Raw Foods have more folate than cooked foods.
Some foods have enzymes that inhibit folate availability.
e.g. Beans, legumes, and cabbage!
Metabolic Functions of Folate
•
•
•
•
Transfers C’s to form new compounds
DNA and AA Synthesis
Homocysteine metabolism
Assists in Neural Tube development prevents:
– Neural tube defects
– Anencephaly
– Spina bifida
• May prevent cancer and Heart Disease
Daily Needs for Folate
Synthetic folic acid absorbed 1.7 times more than Folate.
• RDA Adults: Males and females: 400 μg/day
• Pregnant women and childbearing age: 400 μg/day
– UL: 1,000 μg/day
No Toxicity from foods sources of Folate
Excess intake fortified food or supplements (mask a B12 deficiency)
Food Sources of Folate
Dark green leafy
vegetables,
legumes, seeds
and Liver
Food
Source
Lentils
Asparagus
Spinach
Turnip Greens
Broccoli
Beets
Romaine Lettuce
Bok Choy
Cauliflower
Parsley
Pinto Beans
Garbanzo Beans
Black Beans
Navy Beans
Kidney Beans
Papaya
Brussels Sprouts
Green Peas
Bell Peppers
Green Beans
Serving
Size
1 cup
1 cup
1 cup
1 cup
1 cup
1 cup
2 cups
1 cup
1 cup
½ cup
1 cup
1 cup
1 cup
1 cup
1 cup
1 med
1 cup
1 cup
1 cup
1 cup
Amount
(mcg)
358.38
268.20
262.80
169.92
168.48
136.00
127.84
69.70
54.56
46.21
294.12
282.08
256.28
254.80
230.10
102.12
93.60
86.78
42.32
41.25
DRI/DV Nutrient
(%)
Density
90
7.0
67
30.5
66
28.6
42
26.5
42
13.9
34
8.2
32
36.0
17
15.4
14
8.6
12
19.0
74
5.4
71
4.7
64
5.1
64
4.5
58
4.6
26
3.9
23
7.5
22
3.4
11
6.7
10
4.2
Folate Deficiency
Interferes with normal red blood cell division
Megaloblasts → macrocytes → macrocytic anemia
RBCs abnormally large!
– Macrocytic Anemia
–
–
–
–
Fatigue
Weakness
Irritability
Shortness of breath
Folate Deficiency Linked to Parkinson's Disease
Cobalamin (B12)
2 Forms - Both contain Cobalt.
The Absorption of Vitamin B12
Vitamin B12 bound to
proteins in food and R protein
in saliva goes with it to
collect it.
The protein called intrinsic
factor (IF), made in stomach
helps the intestines absorb
vitamin B12.
Vitamin B12
• Stored mostly in the liver
• Excreted through the bile and urine
• Deficiency can take years to develop.
Metabolic Functions of Vitamin B12
• 2 Coenzymes
Methylcobalamin: homocysteine to methionine;
(prevents homocysteine* buildup)
Deoxyadenosylcobalamin: Succinyl CoA in TCA cycle
•
•
•
•
Activates Folate!
Synthesis of new cells, esply RBCs
Maintains myelin sheath of nerves
Catabolism of AAs and FAs for E Metabolism
Daily Needs for Vitamin B12
RDA Adult: Males and Females: 2.4 μg
Atrophic gastritis: Reduction in HCl production and
B12 not released from protein in food
Bad Bacterial overgrowth reduces B12 absorption
Absorption of the synthetic form is not hindered
Insufficient intrinsic factor & gastric bypass ↓ absorption
Microwave cooking reduces active form by 30-40%.
Vitamin B12 Deficiency
No Toxicity
Deficiency:
•
•
•
•
Zero intake (vegan diets)
Malabsorption (HCl)
↓Pancreatic Enzymes
Gastric Bypass
Macrocytic Anemia
Pernicious Anemia
Fatigue
Shortness of breath
Peripheral Neuropathy (tingling & numbness arms/legs)
Pernicious, Latin meaning ‘destructive’
Pernicious Anemia is a decrease in healthy red
blood cells from lack of vitamin B12.
Need to eat
meat, poultry,
shellfish, eggs,
and dairy
products to get
this vitamin.
Food Sources of Vitamin B12
Food
Source
Sardines
Salmon
Tuna
Cod
Lamb
Scallops
Shrimp
Beef
Yogurt
Cow's milk
Eggs
Turkey
Chicken
Cheese
Serving
Size
3 oz
4 oz
4 oz
4 oz
4 oz
4 oz
4 oz
4 oz
1 cup
4 oz
1
4 oz
4 oz
1 oz
Amount
(mcg)
8.11
5.67
2.66
2.62
2.51
2.44
1.88
1.44
0.91
0.55
0.55
0.42
0.39
0.24
DRI/DV
(%)
338
236
111
109
105
102
78
60
38
23
23
18
16
10
Nutrient
Density
32.2
27.0
13.5
20.4
6.1
14.5
10.4
6.2
4.6
5.5
5.3
1.9
1.6
1.6
Vitamin C
Ascorbic Acid
We Humanoids lack enzyme to make vit C : (
Absorption - Small intestine by active transport
Higher intakes => simple diffusion stomach & intestine
Absorption decreases 50% with intakes > 1 g
More is more likely to be absorbed!
Excreted via kidneys, not stored in the body
Metabolic Functions of Vitamin C
• Collagen Synthesis – Crucial for tissue Health!
• Antioxidant
– Reduces risk for heart disease and cancer
– Accepts/donates e-s to balance free radicals
• Iron absorption is enhanced.
More Functions of Vitamin C
• Boosts the immune system
– Promotes WBC synthesis
• May reduce the body's response to stress
• Aids in the conversion of tryptophan and
tyrosine to serotonin and norepinephrine
• Aids in the synthesis of thyroxine
• Converts cholesterol to bile
• Assists with histamine breakdown
Daily Needs for Vitamin C
RDA Adults: Males: 90 mg/day; Females: 75 mg/day
Smokers: + 35 mg/day!
UL: 2,000 mg/day
Consuming > 3,000mg can cause nausea, stomach
cramps, and diarrhea.
Vitamin C Toxicity and Deficiency
• Deficiency
Scurvy
Prevented with 10mg
of vitamin C per day
Scurvy first presents with:
Fatigue and then formation of spots on the skin, spongy
gums, and bleeding from mucous membranes.
Person feels depressed, pale and partially immobilized.
Advanced scurvy shows open suppurating (pus filled)
wounds, loss of teeth, yellow skin, fever, neuropathy
and finally death from bleeding.
Other Vitamin-Like Compounds
• Some compounds are not vitamins but
essential to overall health.
• Usually enough made in body
• May become essential, e.g., during illness or
chronic disease
Choline
Carnitine
Lipoic acid
Inositol
Choline - cannot be synthesized by body…
Grouped with the B vitamins (but not a vit)
Major Functions
– Part of phospholipid that makes up the cell wall
– Liver metabolism
– Precursor to acetylcholine (nerve transmission)
– Assists in Lipid Transport
– For Fetal Development
Major Food Sources
Animal sources: milk, liver, eggs
Carnitine, Lipoic Acid, and Inositol
All synthesized by body
Carnitine
– Needed to properly utilize fat
– Food sources = Meat and dairy products
Lipoic Acid
– Helps cells generate energy
– Potential antioxidant effects
Inositol
– Assists Cell Membranes
– Food sources – some plants