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Chapter 8: Water Soluble Vitamins. Intro to Vitamins. Food substances that are a “vital” to life 2 classes of vitamins. Fat Soluble Vitamin A D E K. Water Soluble (Bs & C) Ascorbic Acid (Vit C) Vitamin B1, B2, B3, B5, B6, B12 Biotin, Folate.
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Intro to Vitamins • Food substances that are a “vital” to life • 2 classes of vitamins
Fat Soluble Vitamin A D E K Water Soluble (Bs & C) Ascorbic Acid (Vit C) Vitamin B1, B2, B3, B5, B6, B12 Biotin, Folate Vitamins
Vitamins • Structure: individual units • Function: do not yield energy • Requirement: very little (micrograms/milligrams vs. grams)
Vitamins • Availability: • Riboflavin • Vitamin C • Bioavailability: how much a nutrient is absorbed & available for use.
Transport: FSV need carriers Storage: FSV are stored in the cells Toxicity: FSV more likely Requirement: FSV less frequently FSV vs. WSV
General functions of B vitamins • Energy metabolism • Coenzyme for various functions • Neurological
General Deficiencies of B Vitamins • Dermatitis: Skin • Gastrointestinal: GI problems • Nervous system: Central & peripheral • Fatigue
Goal • To understand the specific vitamin associated to a specific disease
Beriberi: Thiamin Wet Beriberi: edema Weakened capillaries Dry Beriberi: Muscle, partial paralysis Damaged nerves
Wernicke-Korsakoff syndrome • Wernicke’s: confusion, disorientation, memory loss, jerky eye movements • Poor nutrition + alcoholism
Thiamin (B1) • Disease 1. Beriberi 2. Wernicke-Korsakoff syndrome • Deficiency • Nervous system • Anorexia • Toxicity: none
Thiamin • Sources:Moderate in all nutritious food • Destroyed by heat • Thiaminase-raw fish • RDA: ~ 1 mg
Riboflavin (B2) Curly toes Inflamed eyelids
Riboflavin (Vit B2) • Disease: Ariboflavinosis • Deficiency:Dermatitis • Skin: Lesions • Mouth: Cracks & redness • Eyes: Inflamed eyelids • Tongue: Smooth, purplish red • Toxicity: none
Riboflavin • Sources: • Milk products • Enriched or whole grains • Destroyed by UV light & irradiation • RDA:~ 1 mg
Before After Pellagra: Niacin (B3)
Pellagra • Niacin • Tryptophan
Niacin (B3) • Deficiency: Pellagra • Symptoms: (4 Ds) 1. Diarrhea – GI 2. Dermatitis - rash 3. Dementia/Depression 4. Death
Niacin • Toxicity • “Niacin Flush”: painful flush, hives, rash • Excessive sweating • Blurred vision • Liver damage
Niacin • Sources: • All protein-containing foods • Tryptophan • RDA: 15mg • UL: 35mg
Biotin Deficiency:
Biotin • Deficiency: • Brain • Dermatitis: Red, scaly rash • Hair loss Avidin: Egg white
Biotin • Sources: • Egg yolks, soybeans, fish, whole grains • Limited production by GI bacteria • AI: 30 g/day
Vitamin (B6) • Functions: 1. Convert tryptophan niacin serotonin 2. Help make red blood cells • Deficiency: • Brain 2. Anemia: microcytic, small-cell type INH medication*
Vitamin B6 • Toxicity: Nervous system • Depression, fatigue, nerve damage • Sources: Meats, potatoes • RDA: 1.3 mg • Toxicity: 100 mg
Folate Fortification • Neural tube defects (Spina bifida)
Folate Deficiency Non-deficient
Folate (folic acid) • Functions • DNA synthesis 2. New cell formation 3. Break down homocysteine • Deficiency • Neural Tube defect • Macrocytic anemia (large-cell type) • Heart disease: High homocysteine
Folate • Folate: Ring + glutamate (supplements) • Food: Ring + polyglutamate
Folate 1. Mouth: polyglutamate 2. SI: broken down to monoglutamate 3. SI: add a methyl group to be absorbed
Folate 4. Cell: CH3 is attached inactive form 5. Activate: Vit B12 takes CH3. 6. Folate & B12 are active for DNA synthesis
Folate • RDA: 400 g • 600 g • Toxicity: 1000 g • Toxicity symptoms: Masks vitamin B12-deficiency symptoms
Vitamin B12Cobalamin • Functions • Coenzymes: energy metabolism • New cell synthesis • Maintain nerve cells • Deficiency symptoms: • Fatigue • Anemia: Macrocytic • Degeneration of p. nerves paralysis
Vitamin B12 • RDA: 2.4 g/day • Sources: Animal & fortified products • Toxicity: none reported
Digestion & Absorption Vit B12 • Diet: Animal products • Stomach: HCl/Pepsin release B12 • SI: B12 binds to *intrinsic factor • Absorbed • GI problems, genetic*, vegetarians
Vitamin C • Functions • Collagen synthesis • Strengthens blood vessel walls • Provides matrix for bone growth • Antioxidant • Strengthens resistance to infection • Increases absorption of iron
Vitamin C • Deficiency disease: scurvy • Deficiency symptoms: • Anemia • Bleeding: gums, blood vessels • Muscle and joint pain • Poor wound healing
Vitamin C • Toxicity symptoms: 1. Brain: Nausea, insomnia, depression, headache, fatigue 2. GI: abdominal cramps, diarrhea, 3. Skin: Hot flashes, rashes UL: 2000 mg
Vitamin C • RDA: • Men: 90 mg • Women: 75 mg • Smokers: + 35 mg • Sources: • Citrus fruits • Cabbage-type & dark green vegetables • Easily destroyed by heat and oxygen
Vitamin C ascorbic acid Vitamin C donate and accept hydrogens (Hs) protects against oxidative damage, antioxidant