Water Soluble Vitamins

1
Water Soluble Vitamins

• Chapter 10

2
Vitamins

• Vital to life are essential
• Organic compounds
• Individual units not linked in chains
• Do not provide energy (kcals)
• Assist with release of energy (coenzymes)
• Needed in small amounts micro/milli grams
• Fruits and vegetables are a primary source

3
Bioavailability

• Rate and extent that a nutrient is absorbed can
  be affected by
• GI efficiency
• Nutritional status
• Source of nutrient
• Food prep methods heat, light, oxygen can
  destroy organic compounds
• Foods may inhibit/enhance absorption
• Precursors inactive forms of vitamins

4
Water Soluble Vitamins

• Eight B vitamins, Vitamin C
• Absorbed via blood
• Transported freely in blood
• Excesses excreted in the urine
• Toxicity with over supplementation
• Must be consumed on a regular basis
• Steam rather than boil vegetables

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Table 10-1Page 323
6
B Vitamins

• Thiamin, riboflavin, niacin, Vitamin B6, folic
  acid, Vitamin B12, biotin, pantothenic acid
• Role as coenzymes
• Each B vitamin is a part of a coenzyme -gt
  deficiency in vitamin -gt deficiency of the
  coenzyme

7
Figure 10-1Page 325
Coenzyme Action
Enzyme
Enzyme
Enzyme
Enzyme
Active site
Coenzyme
CD
Vitamin
Compounds
CD
C
D
B
A
CD
Vitamin
A
A
B
B
New products
Coenzyme
B
A
Active site
Enzyme
Enzyme
Enzyme
Enzyme
Without coenzymes, compounds A, B, and CD dont
respond to their enzymes.
With the coenzymes in place, compounds
are attracted to their sites on the enzymes . . .
. . . and the reactions proceed
instantan- eously. The coenzymes often donate or
accept electrons, atoms, or groups of atoms.
The reactions are completed with either the
formation of a new product, AB, or the breaking
apart of a compound int two new products, C and
D, and the release of energy.
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Figure 10-13Page 346
Metabolic Pathways Involving B Vitamins
Glycogen
Glucose
Some amino acids
Pyruvate
Acetyl--
Some amino acids
Fat
Some amino acids
Some amino acids
TCA Cycle
Yields energy
Other compounds
Yields energy
Yields energy
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Thiamin (B1)

• RDA
• Men 1.2 mg
• Women 1.1 mg
• Toxicity none known
• Function
• Coenzyme in energy metabolism
• Nervous system function nerve cell membrane

10
Thiamin, continued

• Deficiency Beriberi
• damage to nervous system, heart and muscles
• Alcohol abuse a major cause in U.S.
• Can be destroyed by heat

11
In-text Figure Page 326
Pork is the richest source of thiamin, but
enriched or whole-grain products typically make
the greatest contribution to a days intake
because of the quantities eaten. Legumes such as
split peas are also valuable sources of thiamin.
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Figure 10-3Page 327
Thiamin in Selected Foods
Milligrams
Food Serving size
(kcalories)
RDA for men
RDA for women
THIAMIN Many different foods contribute some
thiamin, but few are rich sources. Together,
several servings of a variety of nutritious foods
will help meet thiamin needs. Bread and cereal
selections should be either whole grain or
enriched.
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie
13
Riboflavin (B2)

• RDA
• Men 1.3 mg
• Women 1.1 mg
• Toxicity none known
• Function
• Coenzyme in energy metabolism

14
Riboflavin, continued

• Deficiency Ariboflavinosis
• inflammation of membrane linings of eyes, mouth,
  GI tract, cracks at corners of mouth
• Destroyed by ultraviolet light irradiation

15
Riboflavin - Food Sources

• Milk products, meats, green vegetables, whole
  grains, enriched grains, liver

16
In-text Figure Page 329
All of these foods are rich in riboflavin, but
milk and milk products provide much of
the riboflavin in the diets of most people.
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Niacin (B3)

• RDA
• Men 16 mg equivalents
• Women 14 mg equivalents
• Toxicity gt35 mg niacin flush, blurred vision
• Body can make niacin from tryptophan
• Function
• Coenzyme in energy metabolism
• Has been used to lower blood cholesterol under
  careful medical supervision

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Niacin, Continued

• Deficiency Pellagra
• Diarrhea, dermatitis, dementia, death
• Affects skin, digestive and nervous systems
• Alcohol and corn based diets are deficient

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In-text Figure Page 331
Protein-rich foods such as meat, fish, poultry,
and peanut butter contribute much of the niacin
in peoples diets. Enriched breads and cereals
and few vegetables are also rich in niacin.
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Figure 10-7Page 332
Niacin in Selected Foods
Milligrams
Serving size (kcalories)
Food
RDA for men
RDA for women
NIACIN Members of the meat group (red) are
prominent niacin sources.
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie
21
Biotin

• AI
• Men 30 mcg
• Women 30 mcg
• Toxicity none known
• Function
• Coenzyme in fat glycogen synthesis
• Coenzyme in energy and amino acid metabolism

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Biotin, Continued

• Deficiency rare
• High risk population Alcoholics
• Depression
• Numbness/tingling in arms and legs
• Lethargy
• Dermatitis rash around eyes, nose , mouth
• Raw egg whites contain a protein that binds
  biotin cooking denatures protein

23
Biotin - Food Sources

• Widespread in food
• Cheese, egg yolk, liver, peanut butter, soybeans,
  fish
• Synthesized by GI bacteria

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Pantothenic Acid

• AI
• Men 5 mg
• Women 5 mg
• Toxicity none known
• Function
• Part of Coenzyme A (acetyl CoA)
• Coenzyme in energy metabolism
• Involved in synthesis of lipids,
  neurotransmitters, steroid hormones, hemoglobin

25
Pantothenic Acid, Continued

• Deficiency
• Tingling hands, fatigue, nausea, irritability,
  hypoglycemia, insomnia, restlessness
• Food Sources
• Widespread in foods
• Meat, poultry, whole grains, mushrooms, broccoli,
  avocados
• Can be destroyed by food processing

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Vitamin B6 (Pyridoxine)

• RDA
• Men 1.3 mg
• Women 1.3 mg
• Toxicity gt100 mg neurological damage
• Function
• Coenzyme in amino acid fatty acid metabolism
• Assists in conversion of tryptophan to niacin
  serotonin

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Vitamin B 6, Continued

• Deficiency
• Microcytic anemia
• Weakness, irritability, convulsions
• Nausea, vomiting, flaky skin, sore tongue
• Can be destroyed by heat

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Figure 10-8Page 336
Vitamin B6 in Selected foods
Milligrams
Food Serving size
(kcalories)
RDA for adults (1950 yr)
VITAMIN B 6 Many foodsincluding vegetables,
fruits, and meats offer vitamin B 6 . Variety
helps a person meet vitamin B 6 needs.
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie
29
In-text Figure Page 335
Most protein-rich foods such as meat, fish,
and poultry provide ample vitamin B6
some vegetables and fruits are good sources, too.
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Folic Acid (Folate, Folacin)

• RDA
• Men 400 mg
• Women 400 mg
• Toxicity can mask vit. B12 deficiency
• gt1000 micrograms
• Function
• Part of coenzyme used in DNA synthesis

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Folic Acid - Major Functions

• Major Functions
• New cell synthesis - GI tract, RBC
• Protein synthesis
• DNA/RNA synthesis
• Increased needs w/ pregnancy
• Can be destroyed by heat and oxygen

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Folic Acid - Deficiency

• Macrocytic anemia
• Poor growth, mental confusion, neural tube
  defects, irritability, fatigue
• Precipitated by increased cell synthesis
  situations
• Pregnancy
• CA
• Burns
• Meds

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Figure 10-10Page 339
Decreasing Spina Bifida Rates since Folate
Fortification
30
25
20
Key
Rate per 100,000
15
1991
1996
2001
Neural tube defects have declined since folate
fortification began in 1996.
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In-text Figure Page 340
Leafy dark green vegetables (such as spinach and
broccoli), legumes (such as black beans, kidney
beans, and black-eyed peas), liver, and some
fruits (notably citrus fruits and juices) are
naturally rich in folate.
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Folic Acid - Food Sources

• Foliage - green leafy vegetables, legumes,
  organ meats, orange juice, sunflower seeds,
  fortified grains
• Can be destroyed by heat and oxygen

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Vitamin B12 (Cobalamin)

• General information
• Requires intrinsic factor for absorption
• Intrinsic factor produced in stomach, carries B12
  to small intestine -gt absorption
• RDA
• 2.4 mg for adults
• Toxicity none known

37
Vitamin B 12, Continued

• Major Functions
• Involved in cell division
• Development of RBC, nerve tissue
• Food Sources
• Almost exclusively animal products
• Meat, fish, poultry, milk, cheese, eggs
• Fortified soy milk, fortified cereals

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Cobalamin - Deficiency

• Vegan diet
• Use vit. B12 fortified soy milk
• Increased risk for elderly
• Poor absorption
• Atrophic gastritis
• Lack of intrinsic factor vit. B12 injections
• Pernicious anemia
• macrocytic anemia - can mask folic acid deficiency

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Figure 10-12Page 342
Normal and Anemic Blood Cells
Normal blood cells. The size, shape, and color of
the red blood cells show that they are normal.
Blood cells in pernicious anemia
(mega- loblastic). Megaloblastic blood cells
are slightly larger than normal red blood cells,
and their shapes are irregular.
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Choline

• AI
• Men 550 mg/day
• Women 425 mg/day
• Now considered conditionally essential body
  makes from methionine
• Toxicity gt 3500 mg/day
• Symptoms body odor, sweating, reduced growth,
  liver damage, low blood pressure

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Choline continued

• Functions
• Involved in the synthesis of acetylcholine, a
  neurotransmitter
• Involved in the synthesis of lecithin, a
  phospholipid
• Deficiency causes liver damage rare
• Found in milk, liver, eggs, peanuts

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Vitamin C (Ascorbic acid)

• RDA
• Men 90 mg
• Women 75 mg
• Toxicity gt2000 mg nausea, headache, rash
• Increased needs
• Stress
• Smoking
• Infection
• Surgery

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Figure 10-16Page 350
Vitamin C Intake (mg/day)
3000
Adverse consequences may appear at such a high
dose
2000
Upper level for adults
Limited absorption and little increase in blood
concentrations at higher doses
200
125
Recommendation for men smokers
Recommendation for women smokers
110
100
Saturates tissues
90
RDA for men
75
RDA for women
30
Supports metabolism
10
Prevents scurvy
0
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In-text Figure Page 352
When dietitians say vitamin C, people think
citrus fruits.
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In-text Figure Page 352
But these foods are also rich in vitamin C.
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Vitamin C - Major Functions

• Major Functions
• Anti-oxidant
• Collagen synthesis
• Iron Chelation/Absorption
• Amino Acid Synthesis
• Norepinephrine
• Thyroxine

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Figure 10-18Page 353
Vitamin C in Selected Foods
Milligrams
Food Serving size
(kcalories)
RDA for men
RDA for women
VITAMIN C Meeting vitamin C needs without fruits
(purple) and vegetables (green) is
almost impossible. Many of them provide the
entire RDA in one serving, and others provide at
least half. Most meats, legumes, breads, and
milk products are poor sources.
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie
48
Vitamin C - Deficiency

• Scurvy
• Scaly, dry skin
• Edema
• Bleeding gums
• Poor wound healing
• Infection
• Can be destroyed by heat and oxygen

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B Vitamin Relatives

• Coenzymes in metabolism
• Produced by the body (not essential)
• NOT considered B Vitamins
• Inositol
• Carnitine

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B Vitamin Relatives, Continued

• Compounds promoted as B vitamins
• Pangamic Acid (B15)
• Laetrile (B17)
• Bioflavenoids (Vitamin P)
• PABA
• Ubiquinone
• Carnitine (BT)

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In-text Figure Page 359
Vitamin and Mineral Supplements
52
In-text Figure Page 322
To minimize vitamin losses, wrap cut fruits
and vegetables or store them in airtight
containers.
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Figure 10-4Page 328
Riboflavin Coenzyme, Accepting and Donating
Hydrogens
FADH 2
FAD
FADH 2 carries the hydrogens to the
electron transport chain. At the end of the
electron transport chain, the hydrogens are
accepted by oxygen, creating water, and FADH2
becomes FAD again. For every FADH2 that passes
through the electron transport chain, 2 ATP are
generated.
During the TCA cycle, compounds
release hydrogens, and the riboflavin coenzyme
FAD picks up two of them. As it accepts
two hydrogens, FAD becomes FADH 2 .
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Figure 10-9Page 337
Folates Absorption and Activation
In foods, folate naturally occurs as
polyglutamate. (Folate occurs as mono-glutamate
in fortified foods and supplements.)
Spinach
Ring structure Glutamate Folate

CH3
In the intestine, digestion breaks glutamates
off and adds a methyl group. Folate is
absorbed and delivered to cells.
Intestine
CH3
In the cells, folate is trapped in its inactive
form.
Cell
B12
CH3
To activate folate, vitamin B12 removes and keeps
the methyl group, which activates vitamin B12.
B12
CH3
Both the folate coenzyme and the vitamin B12
coenzyme are now active and available for DNA
synthesis.
DNA
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Figure 10-11Page 341
Folate in Selected Foods
Milligrams
Food Serving size
(kcalories)
RDA for adults
FOLATE Vegetables (green) and legumes (brown) are
rich sources of folate, as are fortified grain
products (yellow).
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie
56
Figure 10-15Page 349
Active Forms of Vitamin C
2H
2H
Ascorbic acid protects against oxidative damage
by donating its two hydrogens with
their electrons to free radicals (mole- cules
with unpaired electrons). In doing so, ascorbic
acid be- comes dehydroascorbic acid.
Dehydroascorbic acid can readily accept hydrogens
to become ascorbic acid. The reversibility of
this reaction is key to vitamin Cs role as an
antioxidant.
57
Animation
Review important food handling practices that
protect the vitamins in foods.
Click to view animation.
58
Table H10-1(1)Page 361
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Table H10-1(2)Page 361
(cont.)
60
In-text Figure Page 364
Structure-function claim
FDA disclaimer
Structure-function claims do not need FDA
authorization, but they must be accompanied by a
disclaimer.
61
Figure H10-1Page 364
An Example of a Supplement Label
Product name
Statement of identity
Descriptive terms if product meets criteria
Contents or weight
Supplement facts panel
The suggested dose
The name, quantity per tablet, and Daily
Value for all nutrients listed nutrients
without a Daily Value may be listed below.
All ingredients must be listed on the label, but
not necessarily in the ingredient list nor in
descending order of predominance
ingredients named in the nutrition panel need not
be repeated here.
Name and address of manufacturer
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Thiamin - Food Sources

• Meats, whole grains, nuts, fruits, vegetables,
  enriched grains, pork

63
Vitamin C - Food Sources

• Food Sources
• Citrus fruits
• Berries
• Cabbage type vegetables
• Dark green vegetables
• Tomatoes, potatoes, mangos, papayas

64
Figure 10-5Page 329
Riboflavin in Selected Foods
Milligrams
Food Serving size
(kcalories)
RDA for men
RDA for women
RIBOFLAVIN Milk and milk products (white) are
noted for their riboflavin several servings
are needed to meet recommendations.
Key
Breads and cereals
Vegetables
Fruits
Milk and milk products
Legumes, nuts, seeds
Meats
Best sources per kcalorie