Transcript Water-Soluble Vitamins

The Water-Soluble
Vitamins
B Vitamins
and
Vitamin C
The Vitamins
• Vitamins vs carbohydrates, fats,
and proteins
–Structure
–Function
–Food contents
The Vitamins
• Bioavailability
• Precursors
• Organic nature
The Vitamins
• Solubility
• Toxicity
The Vitamins
The Vitamins
The B Vitamins
• Coenzymes
Thiamin
• Other names: Vitamin B1
• 1998 RDA
– men: 1.2 mg/day
– women: 1.1 mg/day
• Chief functions in the body
– Part of coenzyme TPP (thiamin
pyrophosphate) used in energy
metabolism
Thiamin
• Significant sources
– Whole grain, fortified, or enriched
grain products
– Moderate amounts in all nutritious
food
– Pork
• Easily destroyed by heat
Thiamin
• Deficiency disease
– Beriberi
• Wet, with edema
• Dry, with muscle wasting
• Deficiency symptoms
– Enlarged heart, cardiac failure
– Muscular weakness
– Apathy, poor short-term memory,
confusion, irritability
– Anorexia, weight loss
• Toxicity symptoms: none reported
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Thiamin
Sources
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Riboflavin
• Other names: Vitamin B2
• 1998 RDA
– Men: 1.3 mg/day
– Women: 1.1 mg/day
• Chief functions in the body
– Part of coenzymes FMN (flavin
mononucleotide) and FAD (flavin
adenine dinucleotide) used in energy
metabolism.
Riboflavin
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Riboflavin
• Significant sources
– Milk products (yogurt, cheese)
– Enriched or whole grains
– Liver
• Easily destroyed by ultraviolet light
and irradiation
Riboflavin
• Deficiency disease: ariboflavinosis
• Deficiency symptoms
– Inflamed eyelids and sensitivity to
light, reddening of cornea
– Sore throat
– Cracks and redness at corners of
mouth
– Painful, smooth, purplish red tongue
– Inflammation characterized by skin
lesions covered with greasy scales
• Toxicity symptoms: none reported
Riboflavin
Sources
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Niacin
• Other names
– Nicotinic acid
– Nicotinamide
– Niacinamide
– Vitamin B3
• Precursor: dietary tryptophan
• 1998 RDA
– Men: 16 mg NE/day
– Women: 14 mg NE/day
• Upper level for adults: 35 mg/day
Niacin
• Chief functions in the body
– Part of coenzymes NAD (nicotinamide
adenine dinucleotide) and NADP (its
phosphate form) used in energy
metabolism
• Significant sources
– Milk, eggs, meat, poultry, fish
– Whole-grain and enriched breads and
cereals
– Nuts
– All protein-containing foods
Niacin
• Deficiency disease: pellagra
• Deficiency symptoms
– Diarrhea, abdominal pain, vomiting
– Inflamed, swollen, smooth, bright red
tongue
– Depression, apathy, fatigue, loss of
memory, headache…similar to raising
some children, or attending college!
Bilateral symmetrical
rash (sunlight
exposure) of pellagra
can be disturbing!
Niacin
• Toxicity symptoms
– Painful flush, hives, and rash (“niacin
flush”)
– Excessive sweating
– Blurred vision
– Liver damage,
– impaired glucose
tolerance
Niacin
Sources
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Biotin
• 1998 adequate intake (AI)
– Adults: 30 g/day
• Chief functions in the body
– Part of a coenzyme used in energy
metabolism, fat synthesis, amino
acid metabolism, and glycogen
synthesis
• Significant sources
– Widespread in foods
– Organ meats, egg yolks, soybeans, fish,
whole grains
– Also produced by GI bacteria!
Biotin
• Deficiency symptoms
– Depression, lethargy, hallucinations,
numb or tingling sensation in the
arms and legs
– Red, scaly rash around the eyes,
nose, and mouth
– Hair loss
• Toxicity symptoms: none reported
Pantothenic Acid
• 1998 adequate intake (AI)
– Adults: 5 mg/day
• Chief functions in the body
– Part of coenzyme A, used in energy
metabolism
• Significant sources
– Widespread in foods
– Organ meats, mushrooms, avocados,
broccoli, whole grains
• Easily destroyed by food processing
Pantothenic Acid
• Deficiency symptoms
– Vomiting, nausea, stomach cramps
– Insomnia, fatigue, depression,
irritability, restlessness, apathy
– Hypoglycemia, increased sensitivity to
insulin
• Toxicity symptoms: none reported
Vitamin B6
• Other names
– Pyridoxine
– Pyridoxal
– Pyridoxamine
• 1998 RDA
– Adults (19-50 years): 1.3 mg/day
• Upper level for adults: 100 mg/day
Vitamin B6
• Chief functions in the body
– Part of coenzymes PLP (pyridoxal
phosphate) and PMP (pyridoxamine
phosphate) used in amino acid and
fatty acid metabolism
– Helps to convert tryptophan to niacin
and to serotonin (a brain hormone)
– Helps to make red blood cells!
Vitamin B6
• Significant sources
– Meats, fish, poultry
– Potatoes, legumes, non-citrus fruits
– Fortified cereals
– Liver
– Soy products
• Deficiency symptoms
– Scaly dermatitis
– Anemia (small-cell type)
– Depression, confusion, abnormal
brain wave pattern, convulsions
Vitamin B6
• Toxicity symptoms
– Depression, fatigue, irritability,
headaches
– Nerve damage causing numbness and
muscle weakness leading to an
inability to walk and convulsions
– Skin lesions
Vitamin
B6
Sources
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Folate: In Summary
• Other names
– Folic acid
– Folacin
– Pteroylglutamic acid (PGA)
• 1998 RDA
– Adults: 400 g/day
• Upper level for adults: 1000 g/day
Folate
• Recommendations
–Dietary folate equivalents (DFE)
–Synthetic is 1.7 fold more
powerful than the natural!
• Also, folate activation needs
vitamin B12
Folate: In Summary
• Chief functions in the body
– Part of coenzymes THF
(tetrahydrofolate) and DHF
(dihydrofolate) used in DNA synthesis
and therefore important in new cell
formation
• Significant sources
– Fortified grains
– Leafy green vegetables, legumes,
seeds
– Liver
Folate: In Summary
• Deficiency symptoms
– Anemia (large-cell type)
– Smooth, red tongue
– Mental confusion, weakness, fatigue,
irritability, headache
• Toxicity symptoms
– Masks vitamin B12-deficiency
symptoms
Folate
• Neural tube defects
–Spina bifida
Folate
• Heart disease
• Cancer
Folate
Sources
Vitamin B12: In Summary
• Other names: cobalamin (and
related forms)
• 1998 RDA
– Adults: 2.4 g/day
• Chief functions in the body
– Part of coenzymes methylcobalamin
and deoxyadenosylcobalamin used in
new cell synthesis
– Helps to maintain nerve cells
– Reforms folate coenzyme
– Helps to break down some fatty
acids and amino acids
Vitamin B12: In Summary
• Significant sources
– Animal products (meat, fish, poultry,
shellfish, milk, cheese, eggs)
– Fortified cereals
• Easily destroyed by microwave
cooking
• Deficiency disease: pernicious anemia
Vitamin B12
• Deficiency of folate or B12 produces
pernicious anemia
Vitamin B12: In Summary
• Deficiency symptoms
– Anemia (large-cell type)
– Fatigue, degeneration of peripheral
nerves progressing to paralysis
• Toxicity symptoms: none reported
Non-B Vitamins
• Choline
Non-B Vitamins
• Inositol
• Carnitine
• Vitamin imposters
Metabolic Pathways Involving B
Vitamins
The B Vitamins
• B vitamin deficiencies
–Glossitis-swollen tongue!
–Cheilosis-ulceration near mouth
• B vitamin toxicities from common
food sources???
• Let’s see…
How much to eat to be toxic??
• A vitamin supplement or…
• 3000 bananas!!
How about 6000 cups of rice!!
Or 3600 chicken breasts!
>10,000 hot wings!!
Vitamin C
Vitamin C
Vitamin C
• Other name: ascorbic acid
• 2000 RDA
– Men: 90 mg/day
– Women: 75 mg/day
– Smokers: + 35 mg/day
• Upper level for adults:
2000 mg/day
Vitamin C
• Chief functions in the body
– Collagen synthesis
• Strengthens blood vessel walls, forms scar
tissue, provides matrix for bone growth
– Antioxidant
– Thyroxin synthesis-helps prevent
goiter
– Amino acid metabolism
– Strengthens resistance to infection
– Helps in absorption of iron
Vitamin C
• Significant sources
– Citrus fruits
– Cabbage-type vegetables, dark green
vegetables (such as bell peppers and
broccoli)
– Cantaloupe, strawberries
– Lettuce, tomatoes, potatoes
– Papayas, mangoes
• Easily destroyed by heat and
oxygen
Vitamin C
• Deficiency disease: scurvy
• Deficiency symptoms
– Anemia (small-cell type)
– Atherosclerotic plaques
– Pinpoint hemorrhages, bone fragility,
joint pain
– Poor wound healing, frequent
infections, bleeding gums, loosened
teeth
– Muscle degeneration and pain,
hysteria, depression, rough skin,
blotchy bruises
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Vitamin C
• Toxicity symptoms
– Nausea, abdominal cramps, diarrhea
– Headache, fatigue, insomnia
– Hot flashes, rashes
– Interference with medical tests,
aggravation of gout symptoms,
urinary tract problems, kidney stones
Vitamin
C
Sources
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin And
Mineral Supplements
• Arguments for supplements
–Correct overt deficiencies
–Improve nutrition status
–Reduce disease risks
–Support increased nutrient needs
–Improve the body’s defenses
Vitamin And
Mineral Supplements
• Who needs supplements?
Arguments for Supplements
• Who Needs Supplements?
– People with nutritional deficiencies
– People with low energy intake – less than 1600
kcalories per day
– Vegans and those with atrophic gastritis need
vitamin B12
– People with lactose intolerance, milk allergies,
or inadequate intake of dairy foods
© 2008 Thomson - Wadsworth
Arguments for Supplements
• Who Needs Supplements?
– People in certain stages of the life cycle
•
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•
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Infants need iron and fluoride
Women of childbearing age need folate
Pregnant women need folate and iron
Elderly need vitamins B12 and D
– People with diseases, infections, or injuries, and those
who have had surgery that affects nutrient digestion,
absorption or metabolism
– People taking medications that interfere with the body’s
use of specific nutrients
© 2008 Thomson - Wadsworth
Vitamin And
Mineral Supplements
• Arguments against supplements
–Toxicity
–Life-threatening misinformation
–Unknown needs
–False sense of security
–Other invalid reasons
Arguments against Supplements
• Other Invalid Reasons:
– Belief that food supply and soil contain inadequate
nutrients
– Belief that supplements provide energy
– Belief that supplements enhance athletic performance
or lean body mass without physical work or faster than
work alone
– Belief that supplements will help a person cope with
stress
– Belief that supplements can prevent, treat or cure
conditions
• Bioavailability and
Antagonistic
Actions
© 2008
Thomson - Wadsworth
Selection of Supplements
• What form do you want?
• What vitamins and minerals do you need?
– Do not exceed Tolerable Upper Intake Levels.
– Be careful about greater that 10 mg of iron.
© 2008 Thomson - Wadsworth
Selection of Supplements
• Are there misleading claims?
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Ignore organic or natural claims.
Avoid products that make high potency claims.
Watch fake preparations.
Be aware of marketing ploys.
Be aware of preparations that contain alcohol.
Be aware of the latest nutrition buzzwords.
Internet information is not closely regulated.
• What about the cost?
– Local or store brands may be just as good as nationally
advertised brands.
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Regulation of Supplements
• Nutritional labeling for supplements is required.
• Labels may make nutrient claims according to
specified criteria.
• Labels may claim that lack of a nutrient can cause a
deficiency disease and include the prevalence of that
disease.
• Labels may make health claims that are supported by
significant scientific agreement.
© 2008 Thomson - Wadsworth
Vitamin And
Mineral Supplements
• Bioavailability
• Antagonistic actions
Vitamin And
Mineral Supplements
• Selection of supplements
–Form
–Contents
–Misleading claims
–Cost
Vitamin And
Mineral Supplements
• Regulation of
supplements
An Example
of a
Supplement
Label