Chapter 7 Vitamins Flashcards
What are precursors/provitamins?
Transform chemically to one or more active vitamin forms
What does a measure of vitamin in a food include?
Vitamin and the vitamin activity potential from its precursors
What is Bioavailability?
The rate and the extent to which a nutrient is absorbed and used
What is malnutrition?
Any condition caused by excess or deficient food energy or nutrient intake or by an imbalance of nutrients
Undernutrition?
Deficient in energy of nutrients
Overnutrition?
Excess energy or nutrients
Subclinical Deficiency?
A deficiency in the early stages, before the outward signs have appeared
What are the fat-soluble vitamins? x4
A
D
E
K
What are the general characteristics of fat-soluble vitamins? x5
-Absorbed into the lymph
-Require Bile for absorption
-Travel in blood in association with protein carriers
-Stored in tissues, Lier and Fatty Tissues
-May be toxic in excess
What are the Water-Soluble Vitamins?
B vitamins
Vit C
What are the 5 characteristics of Water-Soluble Vitamins?
-Absorbed directly into the bloodstream
-Travel feely in bloodstream
-Most are not stored to any great extent
-Excess excreted in urine
-Lower risk of toxicity than fat-soluble vitamins
What vitamin can the body survive for weeks without consuming?
Fat Soluble
What two fat-soluble vitamins cane easily reach toxic levels?
Vit A and D
What foods are fat soluble?
Fats and Oils
What are the 3 forms of active Vit A in the body?
Retinol
Retinal
Retinoic Acid
What is the Vit A plant-derived precursor?
Beta-Carotene
What are the 7 Roles of Vitamin A?
-Vision
-Gene Expression
-Maintenance of Body Linings and Skin
-Immunity
-Growth of Bones and the Body
-Normal Development of Cells
-Critical Importance to reproduction
What is the vitamin-A containing pigment in eye?
Rhodopsin
How is vit A used in the eye?
-Retina contains light-sensitive cells
-light bleaches rhodopsin
-rhodopsin breaks off Vit A, initiating impulse
-Vit A reunites with with pigment
What occurs to eyesight if Vit A runs low in terms of Night Blindness?
-Lag occurs before the eye can see again after a flash of bright light
-Vit A and Pigment do not reunite as fast due to less Vit A
What occurs to eyesight if Vit A runs low in terms of Keratin?
Keratin Accumulation of the cornea occurs.
-Leads to xerosis and xerophthalmia causing permanent blindness
How does skin and body linings use Vit A? x2
-Needed by Epithelial Tissues
-Promotes Cell Differentiation
How does vit A control gene expression?
Retinoic Acid activates or deactivates certain genes, thereby affecting protein production.
How does Vit A contribute to immunity?
-Plays a role in regulation that produce immune system proteins
-Deficiency can lead to a spiral of malnutrition and infection
How does Vit A contribute to Growth?
Assists in growth of bone and teeth - needed in the dismantling step of old bone structure
What are the 4 things that may occurs with Vit A deficiency?
Cell differentiation and Maturation are impaired
-Failure of mucus-producing cells to produce mucus
-A subsequent increase in keratin-producing cells
-Tissues more vulnerable to infection
What is the best way to help prevent/ help Vit A deficiency?
Vit A Supplementation
What causes Vit A Toxicity?
Supplements or Fortified Foods
What are common results of Vit A Toxicity?
May Weaken Bones
Bone and Joint Pain
Abdominal Pain
Stunted Growth
Liver Damage
What are early symptoms of Vit A toxicity?
Loss of Appetite
Blurred Vision
Growth Failure in Children
Headache
Skin Itching
Irritability
What are long-term symptoms of Vit A Toxicity?
Bone Weaking and Hip Fracture
What are 3 Groups of People who are targeted for Vit A Toxicity?
-Pregnant Women (Use supplements)
-Children who mistake chewable vit pills for candy
-Adolescents who take large doses for acne (Accutane = Vit A but Vit A supplements do not help acne)
T or F Beta Carotene Causes Vit A Toxicity
False
Can turn yellow/orange due to deposition in subcutaneous fat
What is the most abundant of the carotenoid precursors
Beta-Carotene
How is Vit A Activity for Vit A precursors measured?
Retinol Activity Equivalents (RAE)
What is 12 mcgs of beta-carotene equilivant to?
1 Microgram (RAE)
Why are deep orange fruits and veggies and dark green veggies good for eyesight?
Rich in Beta-Carotene
(Doesn’t improve vision if Vit A is adequate already)
Lack of foods rich in _____ increases the risk of macular degeneration?
Beta-Carotene
Elevated Beta-Carotene levels in food and blood _____ cancer list?
Reduce
T or F Beta-Carotene supplements show the same benefits than receiving it from food.
False, cancer benefit not seen
-Supplements associated with increased risk of cancer in smokers
What is a major dietary antioxidants?
Beta-Carotene
Where is Vit A Found?
Foods of animal origin
Where is Beta-Carotene found?
Plants
3 sources of good vitamin A in foods?
1)Liver and Fish Oil
2)Fortified Milk and Milk Products
3)Eggs
Is Vitamin D essential
No The body can make all it needs with the help of sunlight
-Although many borders on vit D insufficiency
What are the two roles of Vitamin D?
-Regulation of blood calcium and phosphorus levels and maintains bone integrity
-Functions as a hormone
How does vitamin D regulate calcium?
When more calcium is needed it raises blood calcium levels
-Promotes Ca absorption
-Promotes Ca retention by kidney
-Draws Ca from bone
What diseases does Vit D deficiency promote?
1)High BP
2)Cancer
3)T1D
4)heart Diseases
5)Rheumatoid Arthritis
6)Inflammatory Bowel Disease
7)Multiple Sclerosis
What is Rickets?
Vit D deficiency disease in children
-Abnormal Bone Growth
-Bowed Legs, Outward-Bowed Chest, Knobs on Ribs
What is the adult form of rickets?
Osteomalacia
Who is most susceptible to osteomalacia?
Women with
1)Low Ca Intake
2)Little Sun Exposure
3)Who go through repeated pregnancies and lactation periods
Too much Vit D is a danger to soft tissue? T or F
True, continued overdoses cause high blood Ca level, forcing Ca to be deposited in soft tissues
What is the most toxic of all vitamins in excess?
Vit D
How is Vit D made from sunlight?
UV exposure to a cholesterol compound in the skin transforms it into a vitamin D precursor which is absorbed in the blood
-The liver and kidneys convert precursor to active from of Vit D
Skin synthesis of Vit D can add to toxicity?
False
Sunscreen with SPF above ___ can prevent Vit D syntesis?
8 (including)
Health Canada for Vit D consumption?
Canadian over 50: 400 IU supplement/day
Why may recommendation for Vit D intake increase with age?
Less sunlight exposure, higher risk for osteoporisis
What are 6 sources of Vit D?
Sunlight
Small Amounts of butter, cream and fortified margarine
Fortified Milk
Egg Yolks, liver, fatty fish, and fish oil
-Only certain fortified plants exists
Mushrooms
No Osteroprosis recommendation? 19-50
400-1000 IU daily
No Osteroprosis recommendation? 50+
800-2000 IU daily
Osteoprosis high risk reccomendation?
800 IU-2000 IU regardless of age
What are the 4 tocopherol compounds in Vit E?
1)Alpha
2)Beta
3)Gamma
4)Delta
What tocopherol is the gold standard for Vitamin E activity?
Alpha-Tocopherol
How is Vit E important in preventing oxidative damage of cells?
Antioxidant
-Vit E is preferentially oxidized, thus preventing free radicals
How does oxidative damage occur/result?
Free Radicals
What are the 2 key spots important to Vit E antioxidant effect?
-Lungs: cells are exposed to high O2 concentrations
-Protects red and white blood cells
What are 3 roles of Vit E?
1)Antioxidant
2)Immunity
3)Nerve Development
T or F Vit E supplements always provide health benefits?
F: Unless deficient
How do infants have Vit E deficiency?
Born before the transfer of Vit E. from mother to infant
What is erythrocyte hemolysis?
Rupturing of red blood cells which results in Anemia when infants have vit E def.
What is the effect of Vit E deficiency in adults?
Nerve Damage
How can adults develop Vit E def. (who is susceptible)?
1)Associated with fat malabsorption diseases: Damage to liver, gallbladder or pancreas
2)Low intake with extremely-low-fat diet for years
3)People who rely solely on fat replacers rather than fat
4)Vit E is destroyed by food processing or eating
T or F Vit E toxicity can occur with natural food sources?
False NO TOXCITY
What Vitamin increases the effect of anticoagulant medications?
Vit E
How much of Vit E supplement may cause increased risk?
400IU
How is Vit E Destroyed?
Heat Processing
Oxidation
What foods have Vit E?
-Veggie Oils
-Avocados
-Wheat Germ
-Small amounts of emat, poultry, fish, eggs, milk,nuts,seeds
T or F animal fats have no vit E?
True
What are the two functions of Vit K?
1)Synthesis of blood clotting proteins
2)Synthesis of the normal form of bone proteins that bind minerals to bone
What are 5 Sources of Vit K?
1)Intestinal Bacteria
2)Leafy Green Vegetables -Dark Green Generally richest
3)Canola and Soybean Oil
4)Eggs and Milk contain small amounts
5)Liver is the only rich animal source
What Vit are newborns given and why?
Vit K
-Sterile GI-Tract
-Vit K-Producing Bacteria will establish themselves
T or F Vit K deficieny is unlikely in adults?
True
Who is at risk for Vit K Deficiency?
Newborns
Antibiotic Treatments
Fat Malabsorption
T or F there is no UL for Toxcity of Vit A
True
What may Vit K toxicity cause?
Jaundice and Bilirubin in brain
What is the most common cause of Vit K toxicity?
In infants and preggo women: Toxicity can result from over-supplementation with synthetic Vit K
What are the two water-soluble vitamins?
Vitamin C and B Vitamins
What are 3 characteristics of the Water-Soluble Vit?
-Cooking and washing with water leaches them out of food
-Easily Absorbed
-Excess readily excreted in Urine
General Advice for Meeting Needs of water soluble vit?
Choose foods daily that are rich in water-soluble vitamins, to achieve the recommended intakes regularly
T or F Water soluble vitamins occur from food?
False: occurs in large doses concentrated in some supplements
AKA Expensive Urine
What are the Vitamins for Athletes and why?
Water Soluble (Vit C and D),
Do athletes need water soluble vit supplements?
NO! athletes with appropriate diet generally don’t need vitamin supplements
-Increased energy needs, therefore more food
Why was there a 50% chance of death for crew on ship 200 years ago?
Scurvy, no fruit and veggies
Who did the first experiment and cure for scurvy?
James Lind
What is scurvy?
Vitamin C (ascorbic acid) deficiency
What are the two roles of Vit C?
1)Maintenance of Connective Tissues
2)Antioxidant
How does Vit C maintain connective tissues?
Formation and Maintenance of Collagen
How is Vit C an antioxidant?
1)Protects substances found in foods and the body
2)Protects iron from oxidation promoting its absorption
3)Protects blood constituents from oxidation and helps protect Vit E and return it to its active form
4)Supplements are useful to treat a deficiency disease
What are Vit C deficiency symptoms
-Most scurvy symptoms are due to collagen breakdown
-Loose teeth, bleeding gums, pinpoint hemorrhages, anemia, tenderness to touch, weakness, swollen ankles and wrist, loss of appetite, growth cessation
Who is at risk for scurvy?
1)Elderly
2)Ppl with food insecurity
3)Ppl addicted to alc and drugs
4)Infants fed cow’s milk who do not recieve breast milk or formula
How can scurvy be cured?
100 milligrams of Vit C per day for 5 days
-easily done with food
T of F: Vit C has been shown to prevent colds as it supports immune function.
False, not been shown to prevent colds but does support immune function
What is histamine?
Responsible for sneezing, runny or stuffy nose, swollen sinuses
How does Vit C may reduce cold duration?
Reduces histamine
(2 grams per day for 2 weeks)
-It is antioxidant or other activities may improve the body’s immunity
Is there a placebo effect to the effects of Vit C on colds?
Yes, so not 100% true
(Placebo group reported having fewer colds)
T or F Vitamin C from food is safe?
True
What are the adverse effects of Vit C?
Digestive upsets
(Nauses, ab cramps, gas, diarrhea)
What groups of people may be negatively effected by large amounts of Vit C?
-Massive doses may interefere with medication to prevent blood clotting
-May be dangerous for people with an overload of iron
What is the RDA for Vit C for smokers?
RDA set high 35 mg higher for smokers
-Smoking introduces oxidants that deplete vitamin C
What are vitamin C food sources?
-Citrus fruits
-Dark Green Veggies
-Cabbage Type Veggies
-Strawberries
-Cantaloupe
-Lettuce
-Tomato
-Papaya
-Mangos
-Peppers
-Potatoes
How is Vit C in fruits and veggies destroyed?
Heat and Oxygen (therefore, best to each raw and quickly cooked)
What are the roles of the B Vit?
1)Apart of Coenzymes
2)Metabolism
What Vit B enzyme helps body make protein?
B6
What Vit B enzyme helps cells multiply
Folate and B12
Why is Vit B deficiency so detrimental?
Every cell is affected as cell renewal depends on energy and protein which depends of the B vitamins
-Digestive tract and blood are damaged
T or F in children full recovery may be impossible after a Vit B deficiency?
True: A thiamin deficiency during growth can cause permanent brain damage
T or F Vit B deficiency often shows up alone?
False often with other Vit B because people eat foods that contain mixtures of nutrients
What is the role of Thiamin?
1)Energy Metabolism
2)Nerve Processes and their responding tissues (muscle)
What is the deficiency of Thiamin?
Beriberi and Wernicke-Korsakoff Syndrome
What are Beriberi symptoms?
-Loss of sensation in hand and feet.
-Muscular Weakness
-Advancing Paralysis
-Abnormal Heart Action
What is the difference between wet and dry beriberi?
Wet = Edema / Dry = No Edema
What is Wernicke-Korsakoff Syndrome?
-Alc abuse with severe thiamin deficiency
-Alc displaces food in diet, impairs thiamin absorption and promotes thiamin excretion in urine
What are common symptoms of Wernicke-Korsakoff syndrome?
-Mental Confusion
-Disorientation
-Loss of Memory
-Jerky Eye Movement
-Staggering Gait
-Apathy
-Irritability
What is the treatment for Wernicke-Korsakoff syndrome?
Thiamin by iV or Orally
What are the sources of Thiamin?
-Widespread in healthy foods:
-Pork Products
-Sunflower Seeds
-Whole Grain Cerals
-Legumes
What is the role of Riboflavin?
Energy Metabolism of all Cells
Riboflavin deficiency often accompanies what other deficiency?
Thiamin (Treatment then is the same)
-Often goes undetected because the thiamine symptoms are more severe
What is a common disease associated with Riboflavin deficency?
Arbioflavinosis: Inflammation of membranes of the mouth, skin, eyes and GI tract membranes.
-Smooth, purplish red tongue
Who are most at risk for Riboflavin deficiency?
Children who lack milk products and meat
Sources of Riboflavin?
Widespread in Healthy Foods:
1)Milk and Dairy Products
2) Leafy Green Veggies
3) Whole-grain breads
4)Enriched/fortified grain products
5)Some meats and eggs
What is the role of Niacin?
Energy Metabolism
What is the deficiency associated with Niacin?
Pellagra (called the 4Ds)
What are the 4Ds of Pellagra?
Diarrhea, Dermatitis, Dementia and Death
Who is at risk for Pellagra?
Poorly nourished people living in poverty
(Those with alc addictions)
What are the sources of Niacin?
1)Tryptophan (can be converted)
2)Niacin in Diet (Niacin Equivilants NE)
3)Milk, eggs, meat, poultry, fish, whole grains, fortified and enriched grains, nuts and seeds
How many milligrams of tryptophan is 1 milligram of niacin?
60 milligrams
What occurs with Niacin toxcicty?
-Niacin Flush
-Injure live and blurred vision
What are the 2 roles of folate?
1)DNA synthesis
2)Part of coenzymes for new cell synthesis
What cells are most effected by a Folate Deficiency?
-Red and White Blood Cells
-Cells of GI tract
(Divide rapidly)
What are symptoms of Folate Deficiency?
1)Anemia
2)Diminished Immunity
3)Abnormal Digestive Function
4)Folate deficient diet may increase risk of CVD, colon and cervical cancers
What are Neural Tube Birth Defects (NTDs)?
Result from a Folate Deficiency
-Problems with the spinal cord, mental delay and severely diminished brain size or even death shortly after birth
-Most women eat too few fruits and veggies to supply folate
What Vitamin Deficiency does folate toxicity often mask?
B12
What are Dietary Folate Equivalent (DFE)?
Converts all forms of folate into units that are equivalent to the folate in food
T or F: Synthetic folate in enriched foods and supplement sis absorbed more readily than naturally occurring folate?
True
Folate in foods is given how much credit (in micrograms)?
Full credit
Fortified foods and supplements are given how much credit (in micrograms)?
Extra (1.7 more avaliable)
Sources of Folate?
-Leafy green vegetables
-Fresh-Uncooked veggies and fruits
-Egges
-OJ and Legumes
What is the RDA for folate in healthy adults?
400 mcg DFE/day
What is the RDA for folate in preggo women?
600 mcg DFE/day
What is the role of Vitamin B12?
1)Close relationship with folate
(activated by each other)
2)Maintenance of the sheaths that surround and protect nerve fibres
What occurs with B12 deficiency?
-Damage of Nerve Sheaths
-Creeping Paralysis
-General malfunctioning of nerves and muscles
-Failure of folate to make red blood cells
What other vitamin should be given if there if folate deficiency?
Vit B12 incase of B12 deficiency
T or F: B12 deficiency same as anemia as folate?
True but folate will clear anemia while B12 deficiency will continue
Who is at risk for B12 DEFICIENCY?
-Elderly
-Atrophic Gastritis
-Vegans
How is VB12 absorbed?
Requires Intrinsic Factors
-Compound Made by Stomach
-Stomach acid liberates B12: an intrinsic factor that binds to Vitamin B12
-The complex is then absorbed from the small intestine into the blood
What is pernicious anemia?
A vit B12 deficiency disease is caused by a lack of intrinsic factors and is characterized by large immature red blood cells.
Treated by B12 injections
What are the sources of Vit B12?
-Animal sources are the only sig source
-Bioactivity greatest in milk and fish
-Fortified Plant foods
What are the 9 roles of Vit B6?
1)100+ Rxn in tissues
2)Assists in conversion of one AA to another needed AA-Protein Synthesis
3)Conversion of tryptophan to Niacin
4)Neurotransmitter Synthesis: Conversion of tryptophan to Serotonin
5)Hemoglobin Synthesis
6)Assists in the release of stored glucose from glycogen, contributing to the regulation of blood glucose
7)Immune function
8)Steroid Hormonal Activity
9)Fetal brain and Nervous system development
What are possible symptoms of Vit B6?
-Weakness
-Psychological Depression
-Confusion
-Irritability
-Insomnia
-Anemia
-Greasy Dermatitis
-Convulsions
-Weakened Immune System
Low intakes of which vitamin may be related to increased risk of heat disease?
B6
Are Vitamin B6 Supplements a good idea?
Provides Wayy more than the body needs
-Stick with food
Where is Vit B6 Stored?
Muscle Tissues (unlike other water-soluble vit)
What is the need for vit B6 based on?
Due to its roles in protein metabolism, need is proportional to protein intake
What are the sources of Vit B6?
1)Protein rich-foods: meat, fish, poultry
2)Legumes and Peanut Butter
3)Potatoes, leafy green vegetables, some fruit
What disease is Homocysteine associated with?
elevated homocysteine indicates CVD risk
When deficiencies are associated with increased homocysteine levels?
B vitamins
Folate
B12
B6
-Supplements drop homocysteine levels
What is the role of Biotin?
1)Energy Metabolism
2)Cofactor for several enzymes in the metabolism of carbs, fat protein
What deficiency may occur from consuming large amounts of raw egg whites?
Biotin (cooking eggs denatures protein that binds to biotin keeping it in system)
Sources of Biotin?
Widespread in Foods
What is the role of Pantothenic Acid?
1)Energy Metabolism
2)Coenzyme that plays a role in the release of energy from the energy nutrients
3)Plays a role in 100+ steps concerned with synthesis of lipids, neurotransmitters, steroid hormones and hemoglobin
What percentage of Canadians take vitamin supplements?
46%
What is the debate for vitamin and mineral supplements?
For: People might benefit from a multiple vitamin supplement taken everyday or two
Against: Potential risk outweigh unproven effects: only should be taken when there is a risk of deficiency
Who may need to take supplements?
1)Ppl with nutrient deficiencies
2)Habitual Dieters
3)Vegans/ Atrophic Gastritis
4)Lactose intolerance or Milk Energy
5) People certain ages of live (preggo, elderly, infants)
6)Injuries and infections impairing intake or excretion/metabolism
7)People taking medication interfering with absorption
