Vitamins Flashcards
Exam 4 (Final)
Vitamins: What are they?
Organic compounds
Vitamins: What are they not a source of?
Are not a source of energy
Vitamins:
What form do several vitamins enter the body as?
Several vitamins are inactive in native form and must be converted to active compounds in the body
What are vitamins important for?
Required in minute amounts for growth and maintenance of health
Essential for energy transformation and regulation of metabolic processes
Recommended dietary allowances (RDAs):
What are they?
RDAs represent the average daily dietary intake sufficient to meet the nutrient requirements of nearly all healthy individuals in a particular life stage or gender group
Recommended dietary allowances (RDAs):
How does it change?
RDAs change as we get older, males vs females, increase in pregnancy & breastfeeding, & illness
AI = adequate intake –
only an estimate when there’s not enough evidence to establish an RDA
UL =
highest amount without causing risk
Vitamins: What are the two major groups?
Fat soluble
Water soluble
Vitamins:
What are the fat soluble vitamins?
Vitamins A, D, E, K
Vitamins:
Fat soluble vitamins: How are they absorbed? What does this lead to?
Absorbed by intestines –> lymphatic circulation –> circulating blood
Vitamins:
Fat soluble vitamins: What enhances their absorption?
Their absorption is enhanced by dietary fat intake
Vitamins:
Fat soluble vitamins: How can they be stored?
Can be stored in massive amts
Vitamins:
Fat soluble vitamins: Because they can be stored in massive amounts, what does this lead to?
Extensive storage = less risk for deficiency
Extensive storage = greatly increases potential for toxicity should intake be excessive
Vitamins:
Water soluble - What are they?
Vitamin C
Vitamin B complex: Thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, folic acid, cyanocobalamin
Vitamins:
Water soluble - What kind of change do they undergo in the body?
Undergo minimal storage in the body
Vitamins:
Water soluble - What is needed to replenish?
Frequent ingestion needed to replenish
Should we take multivitamins?
Insufficient evidence
No reason to start or stop
Data supports Vitamin B12 for individuals > 50yrs old
Folic acid in childbearing age & pregnancy
Vitamin D + calcium for postmenopausal females & those at risk for fractures
Vitamin A (Retinol):
Has a role in what?
Has a role in vision (adjust to dim light),
immunity,
skeletal and soft-tissue growth,
cell growth,
skin & mucous membrane maintenance,
antioxidant
Vitamin A (Retinol):
Where is it stored?
Stored in liver, fatty tissue, lungs, skin, spleen, eyes, and testes.
Vitamin A (Retinol):
What kind of foods contain Vitamin A?
Foods with beta-carotene
Dairy, fish, meat
Dark colored fruits & vegs: carrots, cantaloupe, mango, tomato, pumpkin, sweet potato, spinach/dark leafy greens
Vitamin A (Retinol):
Toxicity: What happens if excess is ingested?
Teratogenic in excessive consumption,
liver injury,
bone-related disorders (osteoporosis in postmenopausal women),
harmless orange tint to the skin
Vitamin A (Retinol):
Deficiency results in:
Night blindness
Xerophthalmia - dry conjuctiva
Keratomalacia – degeneration of cornea
Blindness – severe deficiency
Skin lesions, altered mucous mem
Itching, burning, and red, inflamed eyelids
Age-related macular degeneration
Xerophthalmia (Having to do with Vitamin A)
- dry conjuctiva
Keratomalacia (Having to do with Vitamin A)
– degeneration of cornea
Vitamins D
What does Vitamin D regulate?
Regulates calcium and phosphorus and bone mineralization
Vitamins D
What does Vitamin D increase?
Increases bone absorption of calcium
Vitamins D
What does toxicity occur in conjunction with?
Toxicity occurs in conjunction with hypercalcemia
Vitamins D
What does deficiency cause?
Deficiency causes rickets or osteomalacia
Vitamin E (alpha-tocopherol)
What does it do?
Antioxidant properties,
protects RBCs from hemolysis,
may reduce risks of colds & combo with Vit C
delay progression of macular degeneration
Vitamin E (alpha-tocopherol)
What are dietary sources?
Dietary sources: Oils, whole-grain products, nuts
Vitamin E (alpha-tocopherol)
What can a toxicity lead to?
Toxicity may increase risk for bleeding if deficient in Vit K or receiving anticoagulation and increased risk of hemorrhagic stroke by inhibiting platelet aggregation
Vitamin E (alpha-tocopherol)
How common is deficiency? Who does it occur in?
Deficiency rare, exists in those with absorption issues and metabolic disorders
Vitamin K:
What is this required for?
Action required for synthesis of prothrombin and other clotting factors (II, VII, IX, X)
Vitamin K
What does deficiency lead to?
Deficiency produces bleeding tendencies
Vitamin K: How much are infants born with?
Infants born Vit K deficient
Vitamin K:
What do infants receive after delivery?
Receive injection of phytonadione (Vitamin K1) after delivery as routine prophylaxis
Vitamin K
Where is it synthesized?
Synthesized by normal flora of gut
Vitamin K
What would cause a deficiency?
Deficiency caused by dysfunction of bile salts, malabsorption, antibiotics
Vitamin K
Adverse effects
Hypersensitivity reaction- IV, oral, or SQ route preferred
Vitamin K
Therapetic use
Correction or prevention of hypoprothrombinemia and bleeding caused by vitamin K deficiency
Control of hemorrhage caused by warfarin
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What does it help with?
building? production? facilitating? etc…
Builds connective tissue,
collagen production,
general metabolism,
antioxidant,
facilitates iron absorption
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What does it help in the conversion of?
Conversion of folic acid
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What does it help regulate?
Regulation of the respiratory cycle in mitochondria.
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What does it help synthesize?
Synthesis of adrenal steroids
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): How much do smokers need?
Smokers: an additional 35 mg/day
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What are sources?
Citrus fruits/juices (OJ, Lemon juice), tomatoes, potatoes, strawberries, melons, spinach, broccoli
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What does a deficiency lead to?
tissue bleeding,
joint bleeding,
bone fractures,
poor wound healing
tooth loss
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): What are ADRs?
ADRs:
nausea,
abd cramps,
diarrhea
Water-Soluble Vitamins
Vitamin C (Ascorbic acid): How are illnesses effected by vitamin C intake?
Large doses do not reduce incidence of colds, although intensity or duration of illness may be reduced slightly, nor does it promote wound healing
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What is it used for?
Used to reduce cholesterol if given in higher doses
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What happens to it when it enters the body?
Gets converted to active form
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What does it do?
Essential human nutrient, turns food into energy, cellular respiration
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What are sources of it?
Sources: Meats, poultry, fish, peanuts, enriched grains, peanuts, potatoes
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What does a deficiency lead to?
Deficiency – GI sx (abdominal pain, diarrhea, soreness of tongue and mouth),
CNS memory & irritability,
dermatitis,
rough skin
Vitamin B Complex
Niacin (nicotinic acid Vit B3): What are ADEs?
ADEs: toxic – vasodilation
Vitamin B Complex: Riboflavin (vitamin B2)
What does it help with?
Enzymatic reactions
Vitamin B Complex: Riboflavin (vitamin B2)
What happens to it in the body?
Gets converted to active form
Vitamin B Complex: Riboflavin (vitamin B2)
What are food sources?
Food sources: Dairy, bread, fortified cereals
Vitamin B Complex: Riboflavin (vitamin B2)
What does a deficiency lead to?
Deficiency:
Cracked lips and mouth corners,
swollen & red tongue;
dermatitis of scrotum & vulva
Vitamin B Complex: Riboflavin (vitamin B2)
What are symptoms of toxicity?
No sx of toxicity
Vitamin B Complex: Thiamin (Vitamin B1)
What does it do?
Energy and carbohydrate metabolism
Vitamin B Complex: Thiamin (Vitamin B1)
What are sources?
Sources: enriched, fortified, whole-grain products (breads, cereals), pork, legumes
Vitamin B Complex: Thiamin (Vitamin B1)
Deficiency – severe
Who does it occur in? How does it manifest?
Individuals who misuse alcohol are often deficient.
Most common among chronic alcoholics & manifests as Wernicke-Korsakoff syndrome
Vitamin B Complex: Thiamin (Vitamin B1)
Deficiency:
Most common among chronic alcoholics & manifests as Wernicke-Korsakoff syndrome
Serious CNS disorder (neurologic and psychologic sx)
Vitamin B Complex: Thiamin (Vitamin B1)
Deficiency:
Most common among chronic alcoholics & manifests as Wernicke-Korsakoff syndrome
What are symptoms?
Nystagmus, diplopia, ataxia, inability to remember recent past
Vitamin B Complex: Thiamin (Vitamin B1)
Deficiency:
Most common among chronic alcoholics & manifests as Wernicke-Korsakoff syndrome
Failure to correct this syndrome leads to what?
Failure to correct this –> irreversible brain damage
Vitamin B Complex: Thiamin (Vitamin B1)
Deficiency:
Most common among chronic alcoholics & manifests as Wernicke-Korsakoff syndrome
If this syndrome is suspected, how do you treat it?
If suspected, thiamine adm immediately
Vitamin B Complex: Pyridoxine (Vitamin B6)
What does it do?
Involved mainly in metabolism, amino acid absorption, and neurotransmitter synthesis
Vitamin B Complex: Pyridoxine (Vitamin B6)
What happens when it enters the body?
Gets converted to active form
Vitamin B Complex: Pyridoxine (Vitamin B6)
Deficiency- is caused by what?
Inborn metabolism errors, etoh on LT basis
Vitamin B Complex: Pyridoxine (Vitamin B6)
Deficiency- leads to what?
CNS dysfunction
Vitamin B Complex: Pyridoxine (Vitamin B6)
Deficiency- what does CNS dysfunction lead to?
hyperirritability,
peripheral neuritis,
and possible convulsions
Vitamin B Complex: Pyridoxine (Vitamin B6)
Which drug causes a deficiency?
Isoniazid
Vitamin B Complex: Pyridoxine (Vitamin B6)
Toxicity: What are symptoms of toxicity?
Neuro: Uncoordinated movement and nerve damage has been noted in adults taking more than recommended as supplement
Vitamin B Complex: Pyridoxine (Vitamin B6)
Food Sources
Fortified breakfast cereals,
organ meat,
fish,
poultry,
potatoes/starchy vegs
Vitamin B Complex: Cyanocobalamin (vitamin B12)
What is it essential for?
Essential factor in the synthesis of DNA
Cyanocobalamin (vitamin B12)
Where does it mainly function?
Functions mainly in DNA synthesis and cell division
Cyanocobalamin (vitamin B12)
Functions mainly in DNA synthesis and cell division- How does it do this?
By permitting utilization of folic acid, B12 influences cell growth & division
Cyanocobalamin (vitamin B12)
What does it do to folic acid?
Helps catalyze folic acid active form
Cyanocobalamin (vitamin B12)
How does deficiency of folic acid or Cyanocobalamin (vitamin B12)manifest?
Deficiency of either manifests as megaloblastic/macrocyctic anemia
Cyanocobalamin (vitamin B12)
What does it require?
Requires intrinsic factor (secreted by parietal cells of stomach) for absorption
Cyanocobalamin (vitamin B12)
What does a deficiency result in? What are other symptoms?
Cyanocobalamin deficiency results in neurologic damage
Other sx: fatigue, decr appetite, anemia, glossitis
Cyanocobalamin (vitamin B12)
What are good sources of this?
Liver & dairy products good sources
Cyanocobalamin (vitamin B12)
What ways of administeration?
Can be given PO, intranasal, IM, subQ
Folic Acid
What does an absence lead to?
Absence –> blood cell abnormalities
Folic Acid: What is it necessary for?
Essential factor for DNA synthesis
Folic Acid
Food folate versus synthetic folate
Dietary –> must be converted to active form
Folic Acid
What are good sources?
Good sources: peas, lentils, oranges, whole-wheat & enriched grain products, asparagus, beets, broccoli, spinach
Folic Acid
Where is it absorbed? Where does it go?
Absorbed in upper SI –> liver & tissues –> stored or used
Folic Acid
Stability wise how do Food folate compare to synthetic folate
Synthetic form is more stable - PO 400 mcg/day
Folic Acid
Where is folic acid available?
U.S. Food and Drug Administration (FDA) ordered synthetic folate to be added to all enriched grain products
Folic Acid
Deficiency during pregnancy can lead to what?
Deficiency during pregnancy can impair CNS development
Folic Acid
Deficiency during pregnancy can impair CNS development: What does this include?
Can result in neural tube defects, anencephaly, spina bifida
Important for any patient who may become pregnant to take additional folic acid
Folic Acid
High doses of folic acid is associated with what?
Taking high doses of folic acid (more than 800 mcg/day) is associated with an increased risk for certain cancers, and should be discouraged
Herbal Products:
What can it do?
Can interact with conventional drugs
Herbal Products:
How is it marketed?
Marketed without proof of safety or efficacy
Herbal Products:
What can they cause? (Negative stuff)
Can cause significant harmful effects
Increased toxicity & decreased therapeutic effects
Herbal Products:
Many supplements lack reliable info on interactions:
What can St. John’s wort induce?
St John’s wort can induce CYP3A4 & accelerate metabolism of many drugs
Herbal Products:
Ginkgo biloba, feverfew, garlic- What do they do? What does this lead to?
Ginkgo biloba, feverfew, garlic suppress platelet aggregation –> increased bleeding risk in pts receiving antiplatelet drugs, ASA, anticoagulants
Herbal Products:
Ma huang (ephedra) contains what? What does this do?
Ma huang (ephedra) contains ephedrine –> elevate BP, cardiac & SNS stimulation, intensifying effects of pressor agents, cardiac stimulants & counteract therapeutic effects of antihypertensives & CNS depressants
