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The Water-Soluble Vitamins
B Vitamins and
Vitamin C
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
The Vitamins• Vitamins vs carbohydrates, fats,
and proteins– Structure
•Individual units– Function
•Coenzymes and other– Food contents
• mcg or mg
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The Vitamins• Bioavailability
• Precursors
• Organic nature
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The Vitamins• Solubility
• Toxicity
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The Vitamins
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
The Vitamins
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
The B Vitamins• Coenzymes
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Thiamin
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• 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
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• Significant sources– Whole grain, fortified, or enriched
grain products– Moderate amounts in all nutritious
food– Pork
• Easily destroyed by heat
Thiamin
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• 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
ThiaminSources
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Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
Riboflavin
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Riboflavin
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• 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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• Significant sources– Milk products (yogurt, cheese)– Enriched or whole grains– Liver
• Easily destroyed by ultraviolet light and irradiation
Riboflavin
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
RiboflavinSources
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Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
Niacin
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• 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
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Deficiency disease: pellagra• Deficiency symptoms
– Diarrhea, abdominal pain, vomiting– Inflamed, swollen, smooth, bright red
tongue– Depression, apathy, fatigue, loss of
memory, headache– Bilateral symmetrical rash on areas
exposed to sunlight
Niacin
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• Toxicity symptoms– Painful flush, hives, and rash (“niacin
flush”)– Excessive sweating– Blurred vision– Liver damage, impaired glucose
tolerance
NiacinSources
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Biotin
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• 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
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• 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
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• 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
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• Deficiency symptoms– Vomiting, nausea, stomach cramps– Insomnia, fatigue, depression,
irritability, restlessness, apathy– Hypoglycemia, increased sensitivity to
insulin
• Toxicity symptoms: none reported
Vitamin B6
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Other names– Pyridoxine– Pyridoxal– Pyridoxamine
• 1998 RDA– Adults (19-50 years): 1.3 mg/day
• Upper level for adults: 100 mg/day
Vitamin B6
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
– Helps to make red blood cells
Vitamin B6
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Significant sources– Meats, fish, poultry– Potatoes, legumes, noncitrus fruits– Fortified cereals– Liver– Soy products
• Deficiency symptoms– Scaly dermatitis– Anemia (small-cell type)– Depression, confusion, abnormal
brain wave pattern, convulsions
Vitamin B6
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• Toxicity symptoms– Depression, fatigue, irritability,
headaches– Nerve damage causing numbness and
muscle weakness leading to an inability to walk and convulsions
– Skin lesions
VitaminB6
Sources
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Folate
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Folate
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Folate• Absorption
• Activation
– Vitamin B12
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Folate• Recommendations
– Dietary folate equivalents (DFE)•Natural = 1X•Synthetic = 1.7 X natural because
it is more bioavailable
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Folate• Neural tube defects
– Spina bifida
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Jan 1998
Folate• Heart disease
• Cancer
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Folate: In Summary
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• Other names– Folic acid– Folacin– Pteroylglutamic acid (PGA)
• 1998 RDA– Adults: 400 g/day
• Upper level for adults: 1000 g/day
Folate: In Summary
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• 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
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Deficiency symptoms– Anemia (large-cell type)– Smooth, red tongue– Mental confusion, weakness, fatigue,
irritability, headache
• Toxicity symptoms– Masks vitamin B12-deficiency
symptoms
FolateSources
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Vitamin B12
• Activation– Folate
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Vitamin B12
• Absorption– HCl– Pepsin– Intrinsic factor
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Vitamin B12• Deficiency of folate or B12 produces
pernicious anemia
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Vitamin B12: In Summary
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Significant sources– Animal products (meat, fish, poultry,
shellfish, milk, cheese, eggs)– Fortified cereals
• Easily destroyed by microwave cooking
• Deficiency disease: pernicious anemia
Vitamin B12: In Summary
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Deficiency symptoms– Anemia (large-cell type)– Fatigue, degeneration of peripheral
nerves progressing to paralysis
• Toxicity symptoms: none reported
Non-B Vitamins• Choline
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Non-B Vitamins• Inositol
• Carnitine
• Vitamin imposters
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Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
Metabolic Pathways Involving B Vitamins
The B Vitamins• B vitamin deficiencies
– Glossitis– Cheilosis
• B vitamin toxicities
• B vitamin food sources
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
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Vitamin C
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• Chief functions in the body– Collagen synthesis
• Strengthens blood vessel walls, forms scar tissue, provides matrix for bone growth
– Antioxidant– Thyroxin synthesis– Amino acid metabolism– Strengthens resistance to infection– Helps in absorption of iron
Vitamin C
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• 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
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• 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
Vitamin C• Deficiency disease: scurvy• Deficiency symptoms
– the four Hs– Hemorrhage
• Bleeding
– Hyperkeratosis• Flaky skin; poor wound healing
– Hematologic• Anemia (fatigue)
– Hypochondriasis• Depression, anxiety, hysteria
Vitamin C
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
• 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
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5 servings of fruits and vegetables provides about 210 mg
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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
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Vitamin And Mineral Supplements
• Who needs supplements?
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Vitamin And Mineral Supplements
• Arguments against supplements– Toxicity– Life-threatening misinformation– Unknown needs– False sense of security– Other invalid reasons
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Vitamin And Mineral Supplements
• Bioavailability
• Antagonistic actions
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Vitamin And Mineral Supplements
• Selection of supplements– Form– Contents– Misleading claims– Cost
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Vitamin And Mineral Supplements
• Regulation of supplements
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An Example of a Supplement Label
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