Today s Topics. Vitamins: Vital Keys to Health. Understanding Vitamins. Understanding Vitamins 10/19/15

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1 Today s Topics Vitamins: Vital Keys to Health BIOL 103, Chapter 9 Understanding Vitamins Fat Soluble Vitamins: A, D, E, K, and Carotenoids The Water- Soluble Vitamins: Eight Bs and a C Bogus Vitamins Understanding Vitamins Vitamins Needed in small amounts Not an energy source Individual units Organic compounds essenpal for normal funcponing, growth, and maintenance of the body. Understanding Vitamins Fat soluble vs. water- soluble Fat- soluble: vitamins A, D, E, K Absorbed with fat, with lymphapc system Stored in larger quanppes Water- soluble: 8 B vitamins and vitamin C Absorbed into the bloodstream Stored in small amounts Which is more vulnerable to cooking losses? 1

2 Understanding Vitamins Food preparapon affecpons vitamin content in the foods Factors that determine amounts: 1. Source 2. Sunlight 3. Moisture 4. Growing condipons 5. Plant s maturity at harvest 6. Packaging and storage Understanding Vitamins Vitamins in foods Enrichment and forpficapon Enriched: replacing lost nutrients For-fied: adding extra nutrients to foods Some is required by law Provitamins forms of vitamins Vitamin A: The RePnoids FuncPons Vision, cell development and health, immunity Food sources Preformed vitamin A: liver, milk, egg yolks Beta- carotene: yellow/orange fruits and vegetable 4 Forms of Vitamin A Three acpve forms of Vitamin A, collecpvely known as Re-noids: 1. RePnol 2. RePnal 3. RePnoic acid Carotenoids are provitamins: of vitamin A 2

3 FuncPons of Vitamin A 1. Vision: night and day Night and color vision Becomes part of the re-na 2. Cell producpon and differenpapon Help make cells, enzymes, proteins Cell differen-a-on: stem cells à specific cells 3. Skin Required to replace epithelial cells of your skin FuncPons of Vitamin A (cont.) 4. Immune FuncPon Produce immune cells to fight microorganisms 5. ReproducPon Keeps reproducpon tracts healthy Embryo development 6. Bones Bone remodeling Increase in osteoclasts Vitamin A Dietary RecommendaPons Re-nol ac-vity equivalent (RAE) = 1 ug repnol Uses RAE to account for differences between repnoids and carotenoids Sources of vitamin A : repnoids : provitamin A carotenoids ForPfied foods Vitamin A Deficiency 1. Eyes Xerophtalmia 2. The skin and other epithelial cells Hyperkeratosis 3. Immune funcpon Vulnerable to infecpon 4. Other effects: Growth retardapon, bone deformipes, defecpve teeth, kidney stones 3

4 Vitamin A Toxicity Symptoms: fapgue, vomipng, abdominal pain, bone and joint pain, loss of appepte, skin disorders, headache, blurred or double vision, and liver damage 1. Teratogen 2. DiscoloraPon of skin 3. Acne Treatment: RePn- A and Accutane The Carotenoids Plant pigments (deep yellow, orange, red color) Can be converted to vitamin A Beta- carotene supplies the most vitamin A of the carotenoids. 1. Vision 2. Lower risk of certain cancer fruit and vegetables (tomatoes, apricots, carrots), dark green vegetables Absorb 20-40% of what we eat Dietary fat and cooking with heat (breaks down cell walls) increases absorppon The Carotenoids Vitamin D Forms and formapons AcPvated in liver and kidney In the skin, UV light converts a form of cholesterol to D3 à to liver à kidneys à acpve form: 25- hydroxyvitamin D [25(OH)D] or calcitrol FuncPons EssenPal for bone health Regulate blood calcium levels 4

5 Sources: Sun exposure helps acpvate an inacpve form of vitamin D ForPfied milk/foods Oily fish, egg yolk, buker, liver Vitamin D Problem Set 9 QuesPon #1 Name at least three reasons why people around the world will not have similar levels of vitamin D. QuesPon: Why would manufacturers choose milk to be forpfied with vitamin D? Vitamin D Deficiency: In children: Rickets In adults: Osteomalacia or son bones Osteoporosis Toxicity Hypercalcemia: a high concentrapon of calcium in blood à excess deposit of calcium in son Pssues (Stones, Bones, Groans, Thrones, Psychiatric overtones) Melanin, Sunscreens and UV Light Melanin, Chemical Sunscreen = Absorb UV Physical Sunscreen = Reflect UV 5

6 Vitamin E Forms 8 similar compounds EssenPal: alpha- tocopherol Stored mainly in. FuncPons AnPoxidant Protects cell membranes from free radicals Vitamin E Food sources Nuts, seeds, vegetable oil, whole grain, wheat germ oil, fruit, vegetables, and animal products Deficiency Occurs with fat malabsorppon Rare genepc disorder Toxicity Nontoxic and adverse effects have not been found Can interfere with blood Vitamin K Forms: K1 K2 (also requires calcium) Bone formapons Food sources; Green vegetables (spinach, broccoli, brussel sprouts), plant oils, intespnal bacteria Vitamin K Deficiency Rare in healthy people Newborn baby at risk Toxicity Can interfere with anpcoagulant medicapons Toxicity is rare 6

7 Summary of Fat- Soluble Vitamins The Water- Soluble Vitamins: Eight Bs and a C Primarily coenzymes AnPoxidants What to keep in mind about each vitamins: FuncPon Food sources Toxicity vs. Deficiency Vocabs to Know: Coenzyme: a small compound that helps enzymes in biochemical reacpons. Most coenzymes are derived from vitamins or are made from vitamins. Energy Metabolism: process of generapng energy from nutrients (glucose, faky acids, amino acids). Glycogen Metabolism Fat Metabolism Protein Metabolism Thiamin/B1 Part of the coenzyme: thiamin pyrophosphate (TPP): 1. Power protein and faky acid synthesis 2. Breaks down glucose à energy Pork, legumes, nuts and seeds, fish and seafood, enriched grain product Cooking content 7

8 Thiamin/B1 Deficiency/ Ariboflavinosis : Can be caused by chronic alcoholism and poor diet Beriberi: overall profound muscle weakness and nerve destrucpon à can t stand up Toxicity: None reported Riboflavin/B2 1. Coenzyme in energy metabolism 2. Supports anpoxidant acpvity Milk and dairy products Enriched grains, eggs Toxicity: UL is not set Light breaks down riboflavin easily, so foods high in riboflavin are stored in opaque containers. That s why it s rare to see milk in bokles Milk Packaging Niacin/B3 1. Coenzyme in energy metabolism 2. Supports faky acid synthesis Can be made from tryptophan. Need B1, B6, and iron to convert to B3 Whole and enriched grains Meat, poultry, fish, nuts, peanuts 8

9 Niacin/B3 Deficiency: Pellegra: rough skin Four D s: dermapps, diarrhea, demenpa, and death Can worsen if also deficient in,, and iron. Pyridoxine/B6 1., coenzyme in protein and amino acid metabolism, gluconeogenesis (AA à glucose) 2. Produce neurotransmikers 3. Helps to lower blood levels of homocysteine à reduce risk for heart disease Diagram: Toxicity Side effects: skin flushing, liver damage Meat, fish, poultry, potatoes, bananas, sunflower seeds Pyridoxine/B6 Deficiency Microcy-c hypochromic anemia Can also be caused by deficiency in iron. Damage nervous system à depression, headaches, confusion, convulsions. Toxicity Can cause subtle neurological damage Other symptoms: upset stomach, headaches, sleepiness, Pngling/prickling or burning sensapon Folate/B9 1. Coenzyme in DNA synthesis and cell division 2. Coenzyme in amino acid metabolism 3. Needed for normal red blood cell maturapon 4. Works with B6 and B12 to help control homocysteine levels ForPfied cereals, enriched grains Green, leafy vegetables 9

10 Folate/B9 Deficiency: 1. Megaloblas-c anemiaà RBC cannot form à cannot à remain large, immature cells à cannot carry oxygen properly à anemia 2. Birth defects in the Neural Tube: 3. Heart disease from elevated homocysteine levels Toxicity: Can mask vitamin B12 deficiency when you take folate supplements unpl nerve damage is irreversible. In rare cases, some may suffer hives or respiratory distress Folate/B9 Cobalamin/B12 Cobalt- containing compounds (cobalamin) 1. Needed for normal folate funcpons DNA and red blood cell synthesis Metabolize homocysteine 2. Maintains myelin sheath around nerves à nerves protecpon Only animal foods: meats, liver, milk, eggs Some forpfied foods Cobalamin/B12 AbsorpPon: Requires adequate stomach acid and intrinsic factor Deficiency: Can be caused by Pernicious anemia: autoimmune disorder that damages stomach linings à reduced B12 absorppon Nerve damage Toxicity: No UL set 10

11 Pantothenic Acid/B5 FuncPon: 1. Component of coenzyme A à extract energy from nutrients and help build faky acids Widespread in foods Reduced by freezing, canning, refining Deficiency/Toxicity: Rare BioPn/B7 Acts as a coenzyme in: 1. Amino acid metabolism (amino acids à glucose) 2. Faky acid synthesis Cauliflower, liver, peanuts, cheese Protein avidin (raw egg whites) binds biopn and prevents absorppon Deficiency and Toxicity are rare Vitamin C AnPoxidant Needed for collagen synthesis Enhances the absorppon of iron from plant foods Fruits: citrus, strawberries, kiwi Vegetables: broccoli, tomatoes, leafy green, potatoes Deficiency: Scurvy Toxicity: May cause GI distress Vitamin C For some people: kidney stones, iron toxicity 11

12 Summary of Water- soluble Vitamins Choline: A Vitamin- Like Substance FuncPon: Act as a catalyst to help metabolize homocysteine Milk, liver, egg yolk, peanuts; overall is abundant in food Deficiency: Unlikely in healthy people Toxicity: Diarrhea, falling blood pressure, fishy body odor Bogus Vitamins Bogus vitamins: Unnecessary substances found in some supplements Examples: hesperidin, para- aminobenzoic acid (PABA), pangamic acid, rupn Think twice before you buy them! 12