nutrition chapter on fat and water soluble vitamins for exam 4

vitamin D names

cholecalciferol (because it comes from a cholesterol base)

function of vitamin D

calcium regulation and metabolism

calcium and kidneys and vitamin D

calcium encourages the kidneys to retain more calcium and therefore increase calcium in circulation

calcium absorption and vitamin D

enhanced with vitamin D

this is due to vitamin D stimulating the small intestine to produce calbindin

what is calbindin

a calcium binding protein to help increase calcium absorption from the gut to the blood

calcium release from bones and vitamin D

vitamin D stimulates bones to release calcium from reservoirs (demineralization) when levels need to be maintained

what population may need more vitamin D

older populations

this is because they have 1. loss of sex hormones

2. cannot convert vitamin D to its active form as efficiently

3. not enough sun exposure

what is the active form of vitamin D

calcitriol

can our body produce vitamin D?

we can make vitamin D from adequate sunlight esposure

endogenous vitamin D process

1. cholesterol in skin combines with UV rays and provokes a photolysis reaction

2. the precursor molecule dislodges from the cell membrane and enters circulation

3. the LIVER convers the precursor to PREFORM form of vitamin D

4. the KIDNEYS perform conversion to active vitamin D

who is highest risk of vitamin D deficiency

ethnic populations of darker skin tones (90% are deficient)

may be because of more melanin decreasing UV ray absorption

may also be due to lactose intolerance being higher in these populations

vitamin D deficiency conditions

1. rickets in children

2. osteomalacia in adults

3. osteopenia leading to osteoporosis

rickets

condition of vitamin D deficiency in children

manifestations: softening and deformity of long bones (tibia, femur, rib cage, skull)

results in new bone not being able to mineralize properly

BONE LEGGED

osteomalacia

condition of vitamin D deficiency in adults

softening of bone caused by decalcification, and manifests similarly to rickets

osteopenia

vitamin D deficiency

important to connect with osteoporosis

initial condition of decalcification or bone loss due to demineralization and REVERSIBLE if treated

osteoporosis

bone density below threshold and is irreversible

vitamin D deficiency

can be prevented through nutrition and exercise - releases growth factor to encourage bone mineralization

vitamin D toxicity

not common and is usually from over supplementation

this can cause calcification of soft tissue (glass shards in body)

vitamin D deficiency

vitamin D deficiency is HIGH (90% ethnic dark skinned populations, 75% white skinned populations)

vitamin E name

name associated with vitamin E consists of tocopherols (alpha beta gamma)

where is vitamin E found

in cell memberane

what structure does vitamin E take

fatty acid structure

functions of vitamin E

antioxidant

donates electron to neutralize free radicals that can cause damage, but now vitamin E is a radical (vitamin C comes to donate electron and becomes radical but it is OK because it is water soluble so it will be excreted)

enhances immune function

nerve development

should smokers consume vitamin E

NO may cause brain hemmorage

vitamin E deficiency

rare and is mostly in PREMATURE infants

symptoms include ataxia, impaired vision, reproductive failure

vitamin E associated with anemia?

YES

deficiency encourages fragility of red blood cells

toxicity of vitamin E

reduced sexual function in men and malaise

vitamin K name

phylloquinone (active form)

vitamin K structure

has a hydrophobic carbon tail

functions of vitamin K

blood clotting

synthesize bone protein (osteocalcin)

blood clotting cycle

prothrombin > thrombin > which goes into fibrogen > fibrin (clot)

fibrin

helps aggregate thrombocytes (platelets) to clot

megakaryocytes

large cells on vasculature that make up platelets

is there a DRI or UL for vitamin K

NO

where does vitamin K come from

E. coli in the large intestine (80% of it)

deficiency of vitamin K

not common in adults only newborns

why is vitamin K deficiency common in new borns

because they have not yet populated bacteria this is why they are given a shot at birth

usually baby gets bacteria from mothers skin

what risks for vitamin K deficiency

extreme use of antibiotics, as it kills off our gut microbiome and lowers ability to absorb vitamin K

what is included in water soluble vitamins?

vitamin C and B complex vitamins

vitamin C name

ascorbic acid

vitamin C deficiency

scurvy and scorbutic rosary

scurvy

improper formation of collagen and ANEMIA

severe gingivitis tooth loss bleeding impaired growth

scorbic rosary

nodules on ribcage of infants

functions of vitamin C

synthesis of collagen

iron absorption in GI track

antioxidant

collagen and vitamin C

collagen synthesis provides tensile strength for connective tissues (anchor teeth to jaw)

wound healing and scar tissue

iron absorption and vitamin C

crucial for hemoglobin (rings that bind to oxygen) and myoglobin

if you do not have enough vitamin C you wont have enough oxygen in your red blood cells and can lead to anemia

can smokers take vitamin C?

YES they are encourages to increase an additional 35 mg as it can help protect body against tobacco smoke

what is the general function of B - complex vitamins

serve as co enzymes or co factors in energy pathways and other metabolic pathways

assist in ENERGY RELEASE

vitamin B1 name

thiamin (TPP active form)

vitamin B1 function

co factor in the PDH complex and EA1 to make pyruvate to acetly coA

also in PEP cycle

conditions of vitamin B1 deficiency

beriberi and wernike - k syndrome

beriberi

condition where heart becomes enlarged and fluid accumulates beneath the skin

muscles weaken and atrohpy

wet beriberi

affects the cardiovascular system

dry beriberi

affects the nervous system with uncoordinated movements and appear drunk (because you do not want to get your neurons or electrical signals wet)

wernike syndrome`

seen in alcoholics because alcohol is caustic to vitamin B1 and causes deficiency

muscle ataxia and cognitive function loss

vitamin B2 name

riboflavin

active forms of vitamin B2

FMN FAD FADH2

function of vitamin B2

FMN in ETC in complex 1

FAD FADH2 in complex 2 of ETC and krebs cycle

is vitmain B2 usually toxic?

not usually

vitamin A name

retinol (most active form of vitamin A)

retinal, retinoic acid (liver converts to retinOL if consumed in a supplement)

where is retinol stored

in the liver

the HEPATIC STELLATE CELLS

functions of vitamin A

1. integrity of epithelial cells

2. vision

3. gene regulation (activate and deactivate)

4. cell membrane stability

what is the precursor of vitamin A

Beta-carotene

* pigment from carotenoids found in superfoods

* must be converted into vitamin A

does the RDA for vitamin A increase for pregnant women?

yes

preformed vitamin A

ready to use from animal sources

pro-vitamin A

must be converted to active form in the body

what is an example of pro-vitamin A

Beta - Carotene

what is vitamin A crucial in

normal vision

cornea and retina health

vitamin A deficiency conditions

night blindness (reversible)

dry or damaged cornea

permanent vision loss if sustained

immune function

vitamin A and tears

tears need vitamin A to synthesize tears and lubricate eyes

xerophalmia

permanent

dry flaky tissue cornea

vitamin A and cell differentiation

initiates cell differentiation and determination

vitamin A and bones

encourages osteoclasts for bone metabolism

* bone reabsorption occurs when osteoclasts out space osteoBLASTs

osteoclasts

bone cells that break inner part of bone

vitamin A toxicity

fat soluble so stored longer in body (liver)

can cause liver damage and birth defects (teratogenic = birth defects)

PRO vitamin A is not toxic

PRO vitamin A benefits from FOOD

Beta - Carotene may prevent heart disease and cancer

should smokers take vitamin A (beta-carotene supplement)

NO, may lead to increased risk of lung cancer

deficiency of vitamin B2 (riboflavin)

usually co-occurs with other B-complex vitamins due to common food sources

includes inflammation of mucous membranes

cheliosis

nasal cavity irritation

cheliosis

cracks at the corners of the mouth

vitamin B3 name

nicotinamide and nicotinic acid

vitamin B3 main function

release energy from macronutrients

almost every metabolic pathway includes NAD or NADP (which is used in ketogenesis)

what is vitamin B3 used in?

fatty acid synthesis

can we synthesize vitamin B3

YES

what amino acid does the body use to synthesize niacin? (vitamin B3)

tryptophan (precursor to seratonin)

deficiency and vitamin B3

pellagra

pellagra

symptoms include the four Ds

1. diarrhea

2. dermatitis

3. dementia

4. death

nicain toxicity

one of few water soluble that has toxicity

* liver injury

* niacin flush

niacin flush?

from consuming 3 to 4 times much as RDA

symptoms include redness, temporary

what can result in niacin flush?

high doses of nicotinic acid to lower cholesterol

vitamin B6 name

pyridoxine

function of vitamin B6

synthesis of nonessential amino acids

* helps stabilize intermediates during transamination pathways

carbohydrate metabolism

* involved in glycogenolysis (break down of glycogen)

hemoglobin, glucose, and lipid synthesis

neurotransmitter synthesis (necessary for production of neurotransmitters such as serotonin; this is why deficiency is associated with depression)

is vitamin B6 associated with anemia

YES because impaired heme synthesis

toxicity of vitamin B6

numbness in extremities (may be reversible)

vitamin B9 name

folate/folic acid

folate

naturally occuring

folic acid

synthetic and easier to absorb

function of vitamin B9

cell division, dna replication, erythrocyte synthesis, cns formation in fetal development

when does CNS formation begin

first three weeks of pregnancy

vitamin B9 deficiency

inability to synthesize DNA

MACROCYTIC ANEMIA (abnormally large blood cells in few numbers)

neural tube defects

NEURAL TUBE DEFECT MANIFESTATIONS

spinal bifida: failure of spinal cord to close completely

anencephaly: lack of development of brain and skull

vitamin B12 name

cobalamin