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104 Cards in this Set
- Front
- Back
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folate coenzymes THF and DHF require ___ to function correctly.
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vitamin b12
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folate found in food is mostly ____ and must be hydrolyzed by intestinal enzymes to _____.
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polyglutamated; monoglutamated
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after monoglutamation folate gets ___
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methylated and delivered to the liver and other body cells
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the enzyme that demethylates folate requires ___
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vitamin b12
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folate is vulnerable to GI injuries because
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it is constantly secreted back into the GI tract and then reabsorbed
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folate from foods vs fortified foods and supplements
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folate from foods = full credit
fortified foods and supplements = given extra credit (1.7x more) |
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Normal vs pregnant folate recommendations
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400 micrograms(mg) normally vs 600 mg if pregnant
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folate deficiency increases risk of
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neural tube defects
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symptoms of folate deficiency include
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- macrocytic/megaloblastic anemia (big, immature RBCs)
- glossitis - mental confusion - GI tract deterioration |
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risks for folate deficiency
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- infants fed goat milk
- times of increased cell multiplication - cancer drugs, antacids, aspirin |
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vitamin b12 is activated by folate when
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when folate gets demethylated, it gives the methyl group to b12, activating it
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b12 functions
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- synthesis of new cells
- maintains nerve cells - fat metabolism |
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absorption mechanism
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- hcl and pepsin cleave b12 from protein i nthe stomach
- b12 binds to intrinsic factor in the small intestine - at the end of the small intestine the complex is recognized - if gets degraded - b12 gets absorbed |
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daily recommended b12
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2.4 mg/day
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b12 deficiency is usually due to
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- lack of hcl or lack of if
- common in people over 50 with atrophic gastritis (stomach inflammation); atrophic gastritis also caused by iron defieincy or h. pylori infetions |
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b12 deficiency leads to
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pernicious anemia
nerve damage |
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giving folate when really a b12 deficiency is bad because
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will clear up anemia but will not solve b12 deficiency; nerve myelin sheaths will degrade, resulting eventually in creeping paralysis
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b12 sources
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animal sources
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b12 loss
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***microwave cooking (unique)
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riboflavin helps to activate ___, and together they help to synthesize ____
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b6; niacin (by converting tryptophan to niacin)
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choline sources
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- made from methionine
- part of lecithin |
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choline uses
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used to make ach and lecithin
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choline toxicity
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body odour, sweating, low growth, low BP, liver damage
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choline sources
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milk, liver, eggs, peanuts
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inositol
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part of cell membranes
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carnitine
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transports long chain fatty acids from the cytosol to mitochondria
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sodium AI and UL
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1500 mg and 2300 mg
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vitamins differ from carbs, protein, fats in 3 ways
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1. structure: vitamins are complete individual units
2. function: vitamins yield no energy 3. food contents: ingested in micro and milligrams, not grams |
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amount of vitamins available depends on
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1. the amount in the food
2. its bioavailability |
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Minimize vitamin losses by
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refridgerating, using airtight containers, cut after washing, avoid high temperatures and long cooking times, put veggies in soup after water boils, use microwave/steam veggies in small maount of water
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9 water soluble vitamins
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- thiamin
- riboflavin niacin - biotin -pantothenic acid - vitamin b6 - folate - vitamin b12 |
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water soluble vitamins must be obtained fairly regularly because
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small excesses are filtered out by the kidneys (large excesses result in toxicities)
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thiamin (b1) is used as part of
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thiamin pyrophosphate enzyme
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deficiency of thiamin
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usually only in homeless or alcoholics
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alcohol's effects on thiamin
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impairs its absorption and enhances its excretion in urine
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severe thiamin deficiency in alcoholics
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wernicke-korsakoff
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severe thiamin deficiency in non-alcoholics
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beri beri
- found in Indonesia when rice was polished - cardiac hypertrophy, heart failure - muscle weakness - confusion, lose short term memory - anorexia, weight loss |
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thiamin loss
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refining, prolonged cooking (leaches into water)
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thiamin sources
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pork, whole grains (wholly absent from refined foods)
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riboflavin (b2) exists in 2 coenzyme forms
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FMN and FAD
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riboflavin deficiency
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ariboflavinosis
- inflamed membranes in the eyes, GI, mouth, skin - eyes: inflamed lids; sensitive to light - cheliosis: cracks at corner of mouth - skin: lesions with scales - glossitis |
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riboflavin loss
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UV light exposure
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riboflavin sources
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dairy
liver whole grains dark green and leafy veggies |
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niacin (b3) exists in 2 forms
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nicotinic acid or nicotinamide
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major form in the blood is
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nicotinamde
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niacin's role
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2 coenzyme forms: NAD and NADP
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niacin can be made from
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tryptophan
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1mg niacin is made from ____
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60mg tryptophan
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niacin deficiency
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bilateral symmetrical rash on areas exposed to light
pellegra |
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pellegra
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symptoms are the 4 d's:
diarrhea dermatitis dementia death |
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niacin deficiency groundbreaking because
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found disease could be caused by absence in diet.
early 1900s people dependent on corn. 70% of niacin in corn is bound and unuseable; also high in leucine, which interferes with tryptophan conversion |
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niacin toxicity
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niacin flush (capirally dilation)
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niacin loss
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leaches into water
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niacin sources
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animal products, nuts, enriched whole grains
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biotin role
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coenzyme in metabolism
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biotin recommendation
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30 micrograms per day
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biotin deficiency induced by
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raw egg whites (contain avidin that binds biotion)
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biotin deficiency
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red scaly rash on face
nerve impairment depression hallucinations |
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biotin sources
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animal products, GI bacteria
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pantothenic acid
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part of coenzyme A
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pantothenic acid deficiency
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rare "burning feet syndrome" in WWII
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pantothenic acid loss
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canning, freezing, refining
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sources of pantothenic acid
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widespread
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vitamin b6 3 forms
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pyridoxine, pyridoxal, pyridoxamine
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b6 role
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part of coenzymes PLP and PMP used in amino aid and fat metabolism
helps convert tryptophan to niacin |
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unlike other water soluble vitamins, b6 is stored extensively in
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muscle tissue!
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b6 deficiency
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decrease in neurotransmitter synthesis
abnormal compounds produced during tryptophan metabolism accumulate in the brain scaly dermatitis anemia |
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alcohol contributes to b6 loss because
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acetaldehyde dislodges PLP from its enzyme
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____ drug causes b6 deficiency
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INH, a tuberculosis drug
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b6 toxicity
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depression, fatigue, nerve damage (supplements of over 2g faily)
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b6 loss
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heat
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b6 sources
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animal products (plant sources have very low bioavailability)
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Potassium sources
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fresh fruits and veggies; all whole fruits
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K and BP
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low K intake raises BP and high intake prevents hypertension
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Phosphorus is the ___ most abudant minderal in the body
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2nd
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85% of phosphorus is combined with
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Ca in bones and teeth
also activates enzymes and B vitamins, acts as buffer, phospholipids, DNA and RNA |
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Sources of phosphorus
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animal sources
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Magnesium is used for
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Bones (50%) and the rest is in muscles and soft tissues (1% ECF)
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Mg functions as
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catalyst for making proteins and in metabolism
bone health muscle contraction and blood clotting immune function prevents cavities by holding Ca to tooth enamel |
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Mg deficiency
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is common but deficiency symptoms rarely manifest
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Sulfate is in
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essential nutrients such as thiamine, methionine, and cysteine
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Fe is stored by ___ and transported by ____.
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ferritin; transferrin
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Stages of Fe deficiency
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Stage 1 = serum ferritin stores diminish
Stage 2 = transferrin saturation drops Stage 3 = limited hemoglobin production |
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Pica
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craving for non food substances due to iron deficiency
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hemosiderin
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liver converts ferritin to hemosiderin when iron levels are abnormally high
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hepcidin
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hormones made by liver that regulate iron absorption
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zinc roles
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- defends membranes against free radicals
- taste perception - immune function - growth and development - insulin synthesis, storage, release |
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zinc absorption
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varies from 15-40% depending on zinc status
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metallothionein
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retains zinc in cells
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zinc recycling
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incorporated into pancreatic enzymes; enteropancreatic circulation.
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zinc transported by
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albumin mostly
some transferrin |
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zinc deficiency damages
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CNS and immune system and causes diarrhea and growth retardation and delayed sexual maturation and altered taste and poor wound healing
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goitrogens
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antithyroid substance found in foods such as cabbage, kale, brussel sprouts, broccoli
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cretinism
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iron deficiency during preganancy causes mental and physical retardation
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selenium
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in glutathione peroxidase
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selenium deficiency
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Keshan's disease (heart enlargement and insufficiency)
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selenium toxicity
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brittle hair and nails, CNS dysfunction, skin rash, garlic breath
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Copper
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copper oxidizes ferrous iron to ferric iron
helps synthesize collagen protection against free radicals |
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Copper deficiency
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menkes disease (GI cells absorb copper but can't release it into the bloostream)
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Copper toxicity
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wilson's disease (copper builds up in the liver and brain)
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manganese
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acts as cofactor for enzymes
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manganese deficiency caused by
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high iron and calcium intake
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toxicity for manganese
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miners! causes CNS disorders
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fluoride
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crystalline deposits in bones and teeth
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