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25 Cards in this Set
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Vitamins |
Organic compounds that are needed in small amounts to regulate body processes - All vitamins have one or more important functions - Cannot be synthesized by the body - Many are fortified into foods to prevent symptoms of deficiency/increase marketability > This doesn't necessarily make a food healthy |
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Bioavailability |
The rate and extent to which a nutrient is absorbed and used - Approximately 40-90% of vitamins in food are absorbed |
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Factors Affecting Bioavailability |
1) Efficiency of digestion and time of transit through digestive tract 2) Previous nutrient intake and nutrition status 3) Other foods consumed at the same time 4) Method of preparation 5) Source of the nutrient 6) From food vs. supplement |
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Minimizing Vitamin Losses |
Vitamins are organic therefore, they are susceptible to destruction by heat, UV light, or oxidation Losses can be prevented by... 1) Refrigeration of fruits and vegetables 2) Storing cut vegetables, fruits, and juice in airtight containers to reduce oxidation 3) Wash fruits and vegetables before cutting 4) Steam vegetables in small amounts of water, avoid overcooking |
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Water vs. Fat Soluble Vitamins |
1) B vitamins, Choline / A, D, E, K 2) Absorbed into blood / lymph 3) No transport / protein carriers 4) Free in aqueous compartments / in fat cells 5) Excreted from kidneys readily / not readily 6) Toxicity only from supplements / more likely 7) Frequently 1 - 3 days / weeks or months |
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Digestion of Vitamins |
1) Mouth: chewing breaks down food which helps release vitamins 2) Stomach: digestion of food releases vitamins, niacin is absorbed here 3) Gallbladder: releases bile, which emulsifies fat and helps absorb fat-soluble vitamins 4) Pancreas: secretes digestive enzymes that aid in the release of vitamins from food 5) Small Intestine: fat-soluble vitamins are incorporated into micelles and absorbed by diffusion. Water soluble vitamins are absorbed into blood directly (require transport for many) 6) Mucosal Cells: fat-soluble vitamins are repackaged into chylomicrons which enter blood from lymph 7) Large Intestine: bacteria synthesize small amounts of vitamins, some are absorbed |
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B Vitamins |
Function primarily as coenzymes, bind to enzymes to promote their activity - Carry electrons, atoms, chemical groups - We cannot capture energy from vitamins in the form of ATP but it can be used to facilitate chemical reactions |
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List of B Vitamins |
1) B1 (Thiamin) 2) B2 (Riboflavin) 3) B3 (Niacin) 4) B5 (Pantothenic Acid) 5) B6 (Pyridoxine) 6) B7 (Biotin) 7) B9 (Folate) 8) B12 (Cyanocobalamin) |
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Thiamin (B1) |
Coenzyme in glucose and energy metabolism, it is needed for neurotransmitter synthesis and normal nerve function Sources: are pork, whole and enriched grains, seeds, nuts, legumes RI: 1.1 - 1.2mg/day GaR: Alcoholics and those in poverty - No symptoms of toxicity and no UL defined |
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Thiamin (B1) Deficiency |
Deficiency of thiamin can cause Beriberi (weakness, apathy, irritability, nerve tingling, poor coordination, paralysis, heart changes) and Wernicke/Kosakoff Syndrome (weakness, fatigue, enlarged heart, cardiac failure, apathy, poor short term memory, confusion, irritability, muscle paralysis) - Deficiency is rare in North America (same as all B vitamins) - Alcohol blocks thiamin absorption |
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Riboflavin (B2) |
Coenzyme in energy and lipid metabolism Sources: are dairy products, whole and enriched grains, dark green vegetables, meats RI: is 1.1 to 1.3mg/day Deficiency: results in inflammation of the mouth and tongue, cracks at corners of mouth - No groups at risk, toxicity symptoms, or UL |
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Niacin (B3) |
Coenzyme in energy metabolism and lipid synthesis and breakdown Sources: beef, chicken, fish, peanuts, legumes, whole and enriched grains, can be made from tryptophan RI: 14 - 16mg/day Deficiency: results in pellagra (diarrhea, dermatitis on areas exposed to sun, dementia) GaR: those consuming limited diet based on corn, and alcoholics TS: flushing, nausea, rash, tingling, extremities UL: 35mg/day from fortified foods and supplements - High doses may lower LDL and raise HDL |
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Pyridoxine (B6) |
Coenyzme in protein and amino acid metabolism, neurotransmitter, and hemoglobin synthesis, many other reactions Sources: meat, fish, poultry, legumes, whole grains, nuts, and seeds RI: 1.3 - 1.7mg/day Deficiency: headache convulsions, other neurological symptoms, nausea, poor growth, anemia GaR: Alcoholics TS: results in numbness and nerve damage UL: 100mg/day |
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Folate/Folic Acid (B9) |
Coenzyme in DNA synthesis and amino acid metabolism (important for rapidly dividing cells like intestines, skin, bone marrow) Sources: leafy green vegetables, legumes, seeds, enriched gains, orange juice RI: 400μg DFE/day Deficiency: macrocytic anemia, inflammation of tongue, diarrhea, poor growth, neural tube defects GaR: pregnant women, alcoholics TS: masks B12 deficiency UL: 1000mg/day form fortified foods and supplements |
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Macrocytic/Megaloblastic Anemia |
The production of abnormally large, immature, non functional red blood cells - Since folate deficiency negatively affects DNA synthesis, red blood cells don't divide and thus don't mature properly - It is the most obvious sign of folate deficiency in adults |
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Cyanocobalamin (B12) |
Coenyzme in folate and homocysteine metabolism and nerve function Sources: animal products RI: 2.4μg/day (adults) Deficiency: pernicious anemia, macrocytic anemia, nerve damage GaR: vegans, elderly, people with stomach or intestinal disease - No symptoms of toxicity, no UL - Required to activate folate - Intrinsic factor is required for B12 absorption |
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Vitamin C (Ascorbic Acid) |
Coenzyme in collagen (connective tissue) synthesis, hormone and neurotransmitter synthesis, and acts as an antioxidant Sources: citrus fruit, broccoli, strawberries, greens, peppers RI: 75 - 90mg/day Deficiency: scurvy (poor wound healing, bleeding gums, loose teeth, bone fragility, joint pain, pinpoint hemorrhages) GaR: alcoholics, elderly TS: gastrointestinal distress, diarrhea UL: 2000mg/day |
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Antioxidant |
Substance that inhibits oxidation, especially one used to counteract the deterioration of stored food products, removes potentially damaging oxidizing agents in a living organism - Helps maintain the immune system, deficiency is associated with decreased immune function - Protect against oxidative damage by free radicals which steal electrons, damage structure and function > Oxidative damage is associated with caner, diabetes, heart disease, and possibly Alzheimer's and Parkinson's |
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Vitamin A |
Vision, health of cornea, other epithelial tissue, cell differentiation, reproduction, immune function Sources: retinol (liver, fish, fortified milk, margarine, butter, eggs), carotenoids (carrots, leafy greens, sweet potatoes, broccoli, apricots) RI: 700 - 900μg/day Deficiency: xeropthalmia (night blindness, dry cornea, eye infections, poor growth, dry skin, impaired immune function) GaR: poverty (especially children and pregnant women), low fat and low protein diets TS: headache, vomiting, hair loss, liver damage, skin changes, bone pain, fractures, birth defects UL: 3000μg/day of preformed vitamin A - Retinoids - preformed Vit A from animals - Carotenoids - provitamin A from plants (can be converted into retinoids in body)
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Vitamin A Functions |
1) Cell differentiation: specialization of cells, through its role in gene expression, can turn genes on/off 2) Reproduction and Growth: retinol is important for normal fetal growth, bone remodelling, and growth, sperm development 3) Antioxidant: carotenoids only 4) Vision: retinal is part of rhodopsin, visual pigment in retina of eye which helps interpret visual stimuli |
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Vitamin D |
Absorption of calcium and phosphorous, maintenance of bone Sources: egg yolk, liver, fish oils, tuna, salmon, fortified milk, synthesis from sunlight RI: 15 - 20μg/day Deficiency: rickets in children (abnormal growth, misshapen bones, bowed legs, soft bones, osteocalcin in adults, weak bones, and bone and muscle pain) GaR: breast fed infants, children, elderly (especially those with dark skin, little exposure to sunlight and kidney disease) TS: calcium deposits in soft tissues, growth retardation, kidney damage UL: 100μg/day |
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Vitamin D and Calcium Regulation |
Calcium is an essential nutrient needed in many critical body processes (nerve conduction, heart/muscle contraction, etc.) - Vitamin D helps maintain calcium and phosphorous in the body - When calcium levels drop, parathyroid hormine (PTH) is released which activates Vit D at kidneys |
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Vitamin E |
Antioxidant that protects cell membranes Sources: vegetable oils, leafy greans, seeds, nuts RI: 15mg/day Deficiency: results in broken red blood cells, nerve damage, breakdown of cell membranes which can lead to hemolytic anemia GaR: people with poor fat absorption, premature infants TS: inhibition of Vitamin K activity UL: 1000mg/day from supplemental sources |
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Vitamin K |
Synthesis of blood-clotting proteins, and protein in bone Sources: vegetable oils, leafy greens, synthesis of intestinal bacteria RI: 90 - 120μg/day Deficiency: hemorrhage GaR: newborns, people on long-term antibiotics TS: brain damage, anemia - No UL defined - Important for blood clotting |
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Vitamin Supplementation |
1) Dieters (<1600kcal/day) 2) Vegans/Anyone who eliminates dairy (B12, Vit D, Ca2+) 3) Young infants and children (fluoride, Vit D, Iron) 4) Young women/pregnant women (400μg folate) 5) Older Adults (B12, Vit D) 6) Dark skinned individuals (Vit D) 7) Individuals with restricted diets (varies) 8) People taking certain medications (varies) 9) Smokers (Vit C, possibly E) 10) Alchol users (B Vitamins) |
