Nutritional Supplements and CA Treatment Flashcards
(44 cards)
t/f natural is safe / better
false, most toxic substances occur naturally
t/f long term use is not proof that it works or that it’s safe
true, traditional medical systems did not have scientific methods
t/f megadosing antioxidants like vitamin c, beta carotene, and vitamin e are ok
false!! large doses of vitamins/ minerals are toxic
vit c can interfere with body’s ability to absorb copper
phosphorus can inhibit ca absorption
expected to satisfy needs of 50% of people in that age group based on rrl
estimated average requirements
the daily dietary intake levels of a nutrient considered sufficient by f&n board to met reqs of most people
recommended dietary allowance (computed from ear)
where no rda has been established, but amount established is somewhat less firmly believed to be adequate
adequate intake
to caution against excessive intake of nutrients that can be harmful in large amounts
tolerable upper intake levels
highest level of daily consumption with no side effects
vitamin c toxicity
- > 2000 mg/day
- well tolerated unless not absorbed or degraded into oxalate
- oxalate nephrolithiasis
- higher risk if iv form
vitamin a toxicity
- does not lower cancer risk
- long term use causes inc risk for lung ca in high risk individuals
- hepatotoxicity
(>600kU) - toxicity is associated with idiopathic intracranial hpn
- skin manifestations: xerosis, pruritus, erythema, skin hyperfragility, desquamation
vitamin e toxicity
- antioxidant but at megadoses
- no prooxidant effects on ldl
- production of a-tocopheroxyl radicals
- antagonizes effects of vit k (>1000 IU/d) = bleeding
vitamin d and k toxicity
d: hypercalcemia
k: interfere with coumarin based anticoagulation (warfarin)
toxicity of vit b6, b3, b1
b6: neurotoxicity
(b1, b6, b12 protect nerves)
b3: hepatotoxicity
b1: lethargy and ataxia
zinc toxicity
- gastric erosions
- low hdl levels
- impaired cellular immunity (but helps when normal levels)
iodine toxicity
- hypothyroidism (wolff-chaikoff effect)
t/f it can’t hurt to take supplements with regular medicines
false, it can block or speed up absorption of drugs
t/f the fda wouldn’t let them make it if it wasn’t true
false, safety is up to the manufacturer
fda regulations
- all prescription and non prescription drugs are regulated
- dietary supplements are like special foods (no strict safety)
- drugs are unsafe until proven safe
- dietary supplements are considered safe until proven unsafe
problems with supplements
- tainted with germs, pesticides, or toxic heavy chemicals
- do not contain what is listed
- contain different amount than listed
- have ingredients that are not listed
t/f people in chemo may be at higher risk for drug interactions if they take dieteary supplements
true
grapefruit juice and st john’s wort
grapefruit juice: enzyme inhibitor = accumulates drugs
st john’s wort: enzyme inducer = faster clearance of chemo drugs
t/f patients using antioxidants (vit a c e, carotenoids, coq10) were 41% more likely to have recurrence if they use before and during chemo
true
herbs that can increase risk of bleeding
dang gui and botanicals
- should not use these herbs at least 2 weeks prior
herbs that interfere with hormone therapy
red clover and soy = mildly estrogenic and can stimulate hormone sensitive cancers (tamoxifen)
immunosupp and immunostim herbs
immunosupp: st john’s wort
immunostim: astragalus
