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FINAL EXAM - HNSC 1210 > Vitamins - Chapter 7 > Flashcards

Vitamins - Chapter 7 Flashcards

1
Q

The Basics of Vitamins

A
  • Essential, non-caloric organic nutrients
  • Needed in very small amounts
  • Cofactors (helpers) in cell functions
    NOTE: you do not need to memorize the RDA, AI, or
    TUL amounts
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2
Q

Classification of Vitamins

A
  1. Fat Soluble
  2. Water Soluble
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3
Q

Fat soluble: vitamins A, D, E, K

A
  • Dissolve in lipid
  • Require bile for absorption
  • Transported in lymph
  • Stored in tissues (e.g., liver, adipose)
  • May be toxic in excess
  • Caution with supplements
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4
Q

Precursor (Vitamin A)

A

β-carotene (can be converted to vitamin A but need 6x amount

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5
Q

Essential For (Vitamin A)

A
  • Gene expression
  • Vision
  • Epithelial tissue
  • Immune defenses
  • Growth of bone
  • Reproduction
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6
Q

Beta-Carotene (Vitamin A)

A
  • Vitamin A precursor
  • Plant sources: brightly coloured, e.g., deep orange, dark green
  • Effective antioxidant
  • May reduce risk of chronic diseases
    • Eye diseases (e.g., macular degeneration), cancer
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7
Q

Toxicity symptoms (Vitamin A)

A
  • UL = 3000ug/d
  • Stunted growth, muscle/bone soreness, headaches
  • Edema, fatigue, blurred vision
  • Anorexia, nausea, diarrhea
  • Skin disorders, rashes, itching
  • Liver damage, enlargement of spleen
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8
Q

Beta Carotene Toxicity (Vitamin A)

A

Yellowing of the skin

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9
Q

Other Forms of Vitamin A

A
  • Retinoic acid as a drug, directly applied to the skin results in rapid turnover of skin cells
  • Retin-A:
    • Acne; Renova: anti-wrinkle
  • Highly toxic:
    • Serious birth defects if taken during pregnancy
  • Supplementing vitamin A does not help acne
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10
Q

Sunlight (Vitamin D)

A
  • UV radiation converts precursor molecule (cholesterol backbone) in skin
  • Duration specific to skin color: facial area for 15 min 3-7 x/week → 3 h for dark-skinned
  • Manitoba latitude: April to Oct.; use liver stores in winter
  • Sunscreen prevents skin exposure to UV
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11
Q

Sunlight (Vitamin D - Part 2)

A
  • Time of day: midday hours provide maximum direct sun
    exposure
  • Lifestyle: work indoors, homebound
  • Risk of skin cancer, not vitamin D toxicity with ++
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12
Q

Deficiency Can Lead To (Vitamin D)

A
  • Rickets:
    • Bone disease in children
  • Osteomalacia:
    • Bone disease in adults
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13
Q

Research (vitamin D)

A

-Vitamin D deficiency may increase risk of high blood pressure, some cancers, type 1 diabetes, heart disease, rheumatoid arthritis,
inflammatory bowel disease, multiple sclerosis
- Risk of deficiency increases with age

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14
Q

Widespread in Foods (Vitamin E)

A
  • Vegetable oils
  • F&V
  • Fortified cereals and grains
  • Meats and meat alternatives
  • Milk products
  • Destroyed by heat processing
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15
Q

Deficiency (Vitamin E)

A
  • Deficiency is rare (widespread in foods, body stores ++, cells recycle)
  • Erythrocyte hemolysis in premature infants born before 30 weeks
  • Weakness, impaired reflexes (muscle and nerve function)  oxidative
    damage
  • Caused by fat absorption and storage problems
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16
Q

Toxicity (Vitamin E)

A
  • Upper Limit: 1,000 mg/d
  • Toxicity is rare
    • Nausea, fatigue, GI distress, blurred vision
    • ↑ risk bleeding when combined with anticoagulant medications
    • > 400 IU/day: ↑ risk death from all causes
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17
Q

Sources (Vitamin K)

A
  • Bacterial production in colon
    • Affected by absorption problems/illness
    • Antibiotics decrease production
18
Q

Deficiency Rare (Vitamin K)

A
  • Newborns need supplements due to sterile GI tract
  • Taking meds that kill intestinal bacteria (good and bad)
  • Problems with fat absorption
  • Symptoms: easy bruising, hemorrhaging
19
Q

Toxic in Excess (Vitamin K)

A
  • In infants or during pregnancy: taking vitamin K supplement
  • Symptom: jaundice RBC’s break and release pigment (bilirubin)
20
Q

Water Soluble Vitamins

A
  • Vitamins C, B vitamins
    • Dissolve in water
    • Are easily absorbed and excreted
    • Are not stored extensively in tissues
    • Seldom toxic levels
21
Q

Toxicity Risk (Vitamin C)

A
  • Problems if >2 g/day; e.g., altered insulin response to carbohydrate, GI upset
  • Can interfere with anticoagulation meds
    Hemochromatosis (too much iron) should avoid vitamin C supplements
22
Q

The B Vitamins

A
  • Act as coenzymes
  • Involved in energy metabolism
  • Be familiar with name and number:
    1. Thiamin (B1)
    2. Riboflavin (B2)
    3. Niacin (B3)
    4. Pantothenic acid (B5)
    5. Pyridoxine (B6)
    6. Biotin (B7)
    7. Folate (B9)
    8. Cobalamin (B12)
23
Q

Thiamin B1

A
  • Alcohol impairs thiamin absorption and speeds up thiamin excretion
    • Wernicke-Korsakoff syndrome: apathy, irritability, mental confusion,
      disorientation, memory loss
  • Toxicity symptoms:
    • none reported
24
Q

Toxicity (Niacin B3)

A
  • Flushing of skin, red skin rash
  • Tingling sensation in hands/feet
  • Stomach pain, nausea, diarrhea
  • Body adapts to high doses, but monitor for liver damage
25
Q

Niacin as a drug?

A
  • Niacin may be used as part of treatment to lower blood cholesterol levels
  • Self dosing not advised liver damage, peptic ulcers, vision loss as result of large doses
26
Q

At Risk of Deficiency (Folate B9)

A
  • Pregnant individuals
  • Older adults (many medications interact with folate absorption)
  • Alcoholics (decreased folate absorption)
  • Smokers (folate inactivation in lungs)
27
Q

Low folate status may contribute to (Folate B9)

A
  • Hyperhomocysteinemia, a risk factor for cardiovascular disease
  • ↑ risk cancer (colon, cervical)
28
Q

Toxicity

A

Can mask vitamin B12 deficiency (resolves anemia)

29
Q

Cobalamin B12

A
  • Folate and B12 depend on one another for activation
    • Both cause identical anemia with deficiency
30
Q

Intrinsic Factor (Cobalamin B12)

A
  • Need intrinsic factor (IF) for B12 absorption
    • B12 binds intrinsic factor (IF) in stomach and facilitates absorption in small intestine
    • Decreased IF and B12 absorption in elderly
  • If no IF
    • Injections of B12 or oral supplement
31
Q

Risk of Deficiency (Cobalamin B12)

A

Breastfed infants of vegan mothers (adults have body stores for 6 years)

32
Q

Toxicity from Supplements (Pyridoxine B6)

A
  • Symptoms:
    • Numbness due to nerve damage
    • Reversed when quit
      supplements
33
Q

Supplement use (Pyridoxine B6)

A
  • Some take for carpal tunnel syndrome / sleep disorders research showing ineffective
  • Relieving PMS research showing ineffective
34
Q

Controversy 7: Vitamin Supplements (1 - Who Benefits?)

A
  • Those who routinely fail to obtain recommended amounts of vitamins and
    minerals from the diet
  • Those with special needs (e.g., pregnant, older adults)
  • Some valid reasons for taking supplements
  • Research conflicting
    • Some experts believe all healthy people may benefit from daily multivitamin supplement
35
Q

Controversy 7: Vitamin Supplements (2 - Regulation of Supplements)

A
  • Natural Health Products (NHPs):
    • Vitamins and minerals
    • Herbal remedies
    • Homeopathic medicines
    • Chinese traditional medicines
    • Probiotics
    • AAs and EFAs
  • Must be safe for over-the-counter, not require a prescription, and be available
    for self-care and self selection
36
Q

Controversy 7: Vitamin Supplements (3 - Approved Products have)

A
  • Natural Product Number
    (NPN) or
  • Drug Identification Number
    – Homeopathic Medicine
    (DIN-HM)
37
Q

Controversy 7: Vitamin Supplements (4 - Research on Supplementation - Unconvincing outcome)

A

Thought was that supplementation of vitamin E
may provide additional antioxidant protection and decrease chronic disease risk (e.g., heart disease) – research not supporting

38
Q

Controversy 7: Vitamin Supplements (4 - Research on Supplementation -Negative outcomes)

A
  • Supplementation of β-carotene increased incidence of lung cancer in smokers
  • Vitamin A supplements:
    • Bone health (↑ vit A linked with ↑ risk hip fractures)
    • Liver injury at high doses (>10,000 ug/d)
39
Q

Controversy 7: Vitamin Supplements(5 - Reasons to think twice before taking)

A
  • Greater risk toxicity
  • Expensive
  • May give false sense of security
  • Some invalid reasons
    for taking supplements
40
Q

Controversy 7: Vitamin Supplements (6 - Conclusion)

A

Try to make changes to
diet to improve nutritional content and only take supplements when
truly needed

FINAL EXAM - HNSC 1210 (7 decks)

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