exam III [h2o + fat soluble] vitamins Flashcards
DRI
umbrella of all other recommendations
Dietary Reference Intake
RDA
Recommended Daily Allowance
> average level of intake sufficient to meet nutritional requirements of nearly 98% of healthy individuals
AI
Adequate Intake
> when evidence is insufficient to develop RDA - set at a level to ensure nutritional adequacy
EAR
Estimated Average Requirement
> avg daily level of intake estimated to meet the requirements of 50% of individuals
UL
tolerable upper intake level
> max daily intake unlikely to cause any adverse effects
how many vitamins are there?
13!!!!
which factors affect bioavailability?
digestion efficiency
method of food prep
source of nutrient
if other foods are consumed at the same time
what are the 9 water soluble vitamins?
vitamin C thiamin riboflavin niacin biotin pantothenic acid vitamin b6 vitamin b12 folate
what is the most common way to get toxic doses on vitamins?
supplements
what is the MAIN function of water soluble vitamins?
helping with release of energy from macronutrients [not actually utilized in energy production]
vitamin c’s real name?
ascorbic acid
which chemical structure does vitamin C look like?
glucose
how is vitamin C absorbed?
directly
vitamin C’s functions?
cofactor in enzymes
antioxidant
collagen formation
vitamin C can protect against…
colds, cancers, CVD, eye disease
oxaloacetate is a byproduct of excretion of vitamin C. Overconsumption can lead to…
kidney stones
male RDA vitamin C
90 mg/day
female RDA vitamin C
75 mg/day
how much additional vitamin C do smokes require?
+ 35 mg/day
what disease is the deficiency of vitamin C?
SCURVY
4 Hs of Scurvy:
hemorrhagic signs
hyperkeratosis of hair follicles
hypochondriasis [psychological manifestation]
hematological abnormalities
how to treat scurvy
100-500 mg vitamin C supplements until symptoms resolve
UL vitamin C
2 g [2000 mg]
possible symptoms of high doses of vitamin C
osmotic diarrhea
renal stones
vitamin C food sources
citrus fruits dark green veggies strawberries cruciferous veggies potatoes bell peppers papaya mangoes broccoli
thamin is vitamin…
B1
which carriers aid in the absorption of thiamin in the jejunum?
ThTr1
ThTr2
what interferes with the absorption of thiamin?
ethanol
functions of thiamin
energy production + nutrient metabolism
synthesis of pentoses + NADPH
neuro functions
used to convert pyruvate -> acetyl CoA
male RDA thiamin
1.2 mg/day
female RDA thiamin
1.1 mg/day
deficiency of thiamin…
beriberi
dry beriberi
damage to nervous system
wet beriberi
damage to CV system
wernicke’s encephalopathy
presence of neuro symptoms caused by biochemical lesions of mammaliary bodies
triad of dx for wernicke’s encephalopathy
ophthalmoplegia
ataxia
confusion
wernicke-korskoff disease
PERMANENT brain damage
how to treat wernicke’s encephalopathy
50-200 mg thiamine IV
then supplementation PO
LT: alcohol cessation
toxicity of thiamin
no UL established
food sources of thiamin
WGs/fortified/enriched grains flour tortilla cornflakes PORK, chicken, tuna eggs soy milk acorn squash, potatoes
which vitamin number is riboflavin?
vitamin B2
what external source destroys riboflavin?
sunlight
function of riboflavin?
serves as coenzyme
related to energy metabolism
where do you find the highest concentrations of riboflavin?
plasma;
liver, kidney, heart
male RDA riboflavin:
1.3 mg/day
female RDA riboflavin:
1.1 mg/day
deficiency of riboflavin:
ariboflavinosis:
symptoms associated with the MOUTH
toxicity of riboflavin:
no UL; no observed toxicity
food sources of riboflavin:
milk/milk products WG/EG bread, bread products, cereal liver lean meats dark, leafy vegetables [broccoli, turnip greens, asparagus, spinach]
which b vitamin is niacin?
vitamin B3
nicotinic acid is used for…
a medication to improve blood lipid levels
nicotinamide is used as…
a supplement of niacin
what can the body make niacin from?
tryptophan
only if protein needs have been met
functions of niacin
coenzymes; oxidative reductases etc
non-redox roles: riboslyation rxns, enzymatic roles
niacin is excreted through ___ after it is processed in the liver.
urine. duh. it’s water-soluble
male niacin RDA:
16 mg NE/day
female niacin RDA:
14 mg NE/day
disease of deficiency of niacin…
pellegra
4Ds of pellegra
diarrhea
dermatitis
dementia
death
pathophysiology of pellegra
darkening of skin, flakes away
occurs on parts of body exposed to sun
large doses of niacin to improve cholesterol levels
toxicity of niacin occurs most commonly of patients with…
large doses of niacin treating hyperlipidemia
UL of niacin
35 mg/day
food sources of niacin
MEAT FISH POULTRY PB legumes WG/EG mushrooms, potatoes, tomatoes cornflakes
which b vitamin is pantothenic acid?
vitamin b5
which chemical structure is pantothenic acid part of?
CoA
functions of vit B5
component of CoA
nutrient metabolism
acetylation of proteins, sugars, drugs
how is vit B5 excreted?
urine
vit B5 AI men + women
5 mg/day
disease deficiency of vitamin B5?
burning foot syndrome
toxicity of vit B5?
none reported
food sources of pantothenic acid?
very widespread in food
beef, poultry, WG, potatoes, tomatoes, broccoli, oats, egg yolks
biotin is vitamin b…
B7
biotin is made by…
bacteria in the colon
functions of biotin
metabolism; coenzyme carrying activated CO2
nonenzyme: biotinylation, gene expression, cell cycle
how is biotin excreted?
in feces
how does one get a biotin deficiency?
eating raw egg whites
biotin AI for adults [and pregnancy]
30 micrograms/day
toxicity of biotin
none reported; no UL
food sources of biotin
egg yolks liver soybeans fish whole grains [GI bacteria]
folate & folic acid. which is “naturally derived” and white is synthetic?
folate = from food
folic acid = synthetic
when did fortification of folate begin?
1998
which form is folate [folic acid] found in fortified foods?
monoglutamate
functions of folate?
AA + choline metabolism
gene expression
nucleotide metabolism
associations w disease
1 DFE folate …
1 microgram of food folate
- 6 ug of folic acid/fortified food consumed w/meal
- 5 ug folic acid from a supplement taken on an empty stomach
folate is synergistic with…
vitamin B12
folate RDA for adults:
400 ug/day
deficiency of folate is…
megaloblastic macrocytic anemia
UL for folate…
1 mg synthetic folate
neural tube defects can be prevented by…
enough folate early in pregnancy
folate may protect against…
cardiovascular disease
cancer
food sources of folate
legumes fruits & veggies ESP green leafy pinto beans legumes
vitamin B12 is also known as…
cobalamin
where do you find most of B12
in animal products
how is B12 digested/absorbed?
in stomach; HCl + pepsin release B12 from proteins from which its attached in food
what factor can impair the absorption of B12?
decreased stomach acid
functions of vitamin B12
conversion of homocysteine -> methionine
conversion of 1-methylmalonyl CoA –> succinyl CoA
RDA of vitamin B12 for adults
2.4 ug/day
deficiency of vitamin B12
megaloblastic macrocytic anemia
toxicity of vitamin B12
n/a; no UL
what is atrophic gastritis?
chronic inflammation of stomach + damaging cells of stomach
what is pernicious anemia?
lack of intrinsic factor causing vitamin B12 deficiency
vitamin b12 food sources
MILK + FISH best sources
almost exclusively from animal sources
vitamin b6 is also known as…
pyridoxine
where is vitamin b6 stored?
exclusively in muscle tissue
functions of vit b6
coenzymes of MANY reactions
modulate gene expression
how is vitamin b6 excreted?
urine
vitamin b6 RDA for adults 19-50?
1.3 mg/day
vitamin B6 RDA for males 51+?
1.7 mg/day
vitamin B6 RDA for females 51+?
1.5 mg/day
deficiency for b6 is rare but increased for…
older adults
alcoholism
certain drug therapies
vitamin b6 toxicity symptoms?
sensory + peripheral neuropathy
UL for vitamin B6?
100 mg/day
what gastric secretion do fat-soluble vitamins require for digestion?
bile!
where are excessive fat-soluble vitamins stored in the body?
liver
fat stores
what is the precursor for vitamin A and carotenoids?
beta-carotene
what are the three forms of retinoids?
retional
retinal
retinoic acid
3 main functions of retinoids?
vision
growth
protein synthesis
what are carotenoids?
red orange, yellow, lipid soluble pigments found in many plants
dietary sources of vitamin A?
liver dairy products eggs fatty fish oils COLORFUL veggies
what must happen before vitamin A is absorbed?
it must be digested!
how much vitamin A is actually absorbed?
70-90%
where are carotenoids & retinols metabolized?
in enterocytes
function of retinol binding protein II?
transporter into enterocyte
how is retinoic acid absorbed?
directly in the blood
how do chylomicrons transport?
into the lacteal -> lymph
which protein is involved with vision?
rhodopsin
where are excessive fat-soluble vitamins stored in the body?
liver
fat stores
what is the precursor for vitamin A and carotenoids?
beta-carotene
what are the three forms of retinoids?
retional
retinal
retinoic acid
3 main functions of retinoids?
vision
growth
protein synthesis
what are carotenoids?
red orange, yellow, lipid soluble pigments found in many plants
dietary sources of vitamin A?
liver dairy products eggs fatty fish oils COLORFUL veggies
what must happen before vitamin A is absorbed?
it must be digested!
how much vitamin A is actually absorbed?
70-90%
where are carotenoids & retinols metabolized?
in enterocytes
function of retinol binding protein II?
transporter into enterocyte
how is retinoic acid absorbed?
directly in the blood
how do chylomicrons transport?
into the lacteal -> lymph
vitamin A’s role in nuclear function
binds to nuclear receptors; enhances transcription of selected genes
quenching
inactivation of electronically excited molecules [free radicals]
carotenoid functions
eye health
decrease in heart disease [antioxidants] + LDL
decrease in cancer
in excess, which other vitamin will vitamin A interaction with the absorption of?
vitamin K
how is vitamin A excreted?
urine & feces
sm amount passed through lungs
how are some vitamin A metabolites recycled?
returned to enterohepatic circulation
RDA vitamin A for men
900 ug RAE
RDA vitamin A for women
700 ug RAE
where is most vitamin A stored?
in the liver
what is the most common deficiency of vitamin A?
night blindess
RDA for 1-70 yrs old
600 IU [15 ug]
why should retinoids not be used during pregnancy?
they are teratogenic
UL of vitamin A
3000 ug RAE
hyperkeratinosis
discoloration of the skin; not harmful
how to assessment for vitamin A deficiency
eye exams
what is vitamin D’s common name?
calciferol
D2
ergocalfierol
active form [found in supplements]
D3
cholecaliferol
inactive form [found in sun & plants]
which foods naturally contain vitamin D?
fatty fish
shiitake mushrooms
which foods are often fortified with vitamin D?
milk
dairy products
OJ
cereals
how long do you need to be in the sunlight to get vitamin D absorption?
only 10 mins
what does vitamin D “act like” instead of a vitamin?
a hormone
food recommendation of vitamin D if not enough sunlight?
2 cups vitamin D milk
does vitamin D require digestion?
nope;
passive diffusion through micelles
which form of vitamin D metabolized to in the liver?
25-OH - hydroxy
which form of vitamin D metabolized to in the kidney?
25-(OH)2 - dihydroxy
what is the MAIN function of vitamin D in the body?
serum calcium homeostasis
what is the normal serum of calcium value?
8.5-10.5 mg/dL
diagnostic range of hypocalcemia?
< 8.5 mg/dL
how does vitamin D raise blood concentrations of Ca/P
- enhances absorption from GI tract [when diet is sufficient]
- provides needed minerals from other sources [when diet is insufficient]
- resorption by kidneys + mobilization from bones -> blood
rickets
vitamin D deficiency in children; failure of growing bones to mineralize
osteomalacia
vitamin D deficiency in adults; failure to mineralize ALREADY formed bone; failure to synthesize adequate vitamin D
UL of vitamin D
4000 IU [100 ug]
vitamin E classes:
- tocepherols
2. tocotrienols
food sources of vitamin E
nuts, nut butters, seeds, plant oils
high fat meats
how is vitamin E destroyed?
air, light, heat
absorption range of vitamin E
20-70%
vitamin E is also…
an antioxidant
may protect against CVD from LDL oxidation
menadione
synthetic form of vitamin K
what nutrients does vitamin E interrupt?
selenium
vitamin c
polyunsaturated fats
RDA for adults vitamin A
15 mg alpha-tocepherol
which population has an increased need for vitamin E?
smokers
UL for vitamin E
1000 mg alpha-tocepherol
plasma concentration for deficiency vitamin E
< 5 mg/dL
plasma concentration of possible toxicity of vitamin E
> 20 mL/dL
why are babies given vitamin K at birth?
they don’t have the gut biome that adults do
phulloquinones sources
leafy green vegetables
menaquinones
from bacteria, fermented cheese, liver, soy product
menadione
synthetic form
how quickly is vitamin K turned over?
VERY quickly, every 1.5 days
vitamin K is required to transform fibrinogen –>
fibrin
AI vitamin K for males
120 ug/day
AL vitamin K for females
90 ug/day
toxicity of vitamin K occurs with…
ONLY synthetic form [menadione]
who is at risk of vitamin K deficiency?
newborns malabsorption those on antibiotic therapy HIV/AIDS drugs organ transplant patients
assessment of nutriture of vitamin K
plasma/serum phylloquinone
blood clotting/prothrombin time
