advanced nutrition final

vitamin A biochemical function

synthesis of rhodospin; cell growth and differentiation, bone development and immune function

vitamin a food source

liver, dairy, fortified foods

provitamin biochemical function

antioxidant

provitamin food source

sweet potato, carrots, spinach, butternut squash, greens, broccoli, and cantaloupe

vitamin D biochemical function

regulator of bone mineral metabolism, blood calcium homeostasis, cell differenctiation, proliferation, and growth

vitamin D food sources

fatty fish & oils, fortified foods

vitamin E function

antioxidant

vitamin E food source

vegetable oils, nuts, and seed

vitamin k function

activates blood clotting factors and proteins in bone by y-carboxylating glutamic acid residues

vitamin k food sources

veggies, esp. leafy, and legumes

rough, red, bumpy skin

vitamin A

muscle weakness and pain

vitamin d

excessive bone growth

vitamin A

inadequate bone mineralization and pain

vitamin d and k

red blood cell fragility and hemolytic anemia

vitamin e

prolonged blood clotting

vitamin k

pigmented retinopathy

vitamin E

night blindness (nyctalopia)

vitamin A

xerosis, bitot’s spots (in conjunctiva)

vitamin A

xerosis, ulcerations/keratomalacia (cornea)

vitamin a

absoprtion of vitamin a

(lumen) dietary retinyl esters and retinal → retinol → (mucosa) combine with 2 molecules retinaldehyde to retinyl esters → chylomicrons → (lymph and blood) → retinyl esters to fatty acid or reinol → retinal binding protein → (blood) retina, gonads, skin, and epithelia

vitamin A plays

critical role in vision

Vitamin A in vision

**diagram on page 9 of lecture**

vision

retinal component of rhodopsin (rods)

converts light to nerve impulse

cis-retina → trans-retinal

transport of vitamin A in eye

dietary retinol transported as retinyl esters in chylomicrons

retinol secreted by liver with plasma retinol binding proteins

retinol in tissues

oxidized to retinoic acid and binds to nuclear receptors

activate retinoic acid receptor to stimulate genes

13- cis retinoic acid (isotretinoin)

treats severe acne

all trans retinoic acid (tretinoin)

treats psoriasis and promyelocytic leukemia

deficiency of rhodopsin (vitamin a)

causes night blindness, earliest sign of vitamin a deficiency

xerophthalmia

form of blindness due to vitamin a deficiency

ulceration of cornea

half a million children each year go blind

toxicity of vitamin a

bone fragility, scaly dermatitis, enlarged liver/spleen, nausea and diarrhea

esterified retinol

stored in liver

stellate and parenchymal cells

vitamin a transported

in blood via retinol binding protein (RBP) and transthyretin (TTR)

carotenoids transported

part of lipoproteins

stored in liver and adipose

retinal function

vision → rhodopsin

retinoic acid function

gene expression

homodimers and heterodimers

cellular differentiation

keratinocytes

bone metabolism vitamin a

osteoblasts and clasts

carotenoids

antioxidant

late manifestation of severe deficiency of vitamin a results in development of

xerophthalmia

what type of soluble is vitamin a

fat soluble vitamin stored in liver and fat

vitamin D function

promotes calcium absorption, need for healthy growth/remodel bone, influence action of genes, modulation of cell growth, neuromuscular and immune function and reduce inflammation

vitamin d regulation of blood calcium levels

increases intestinal absorption, kidney reabsorption, and resorption from bone to blood

vitamin d function

immune function, cell growth/differentiation, blood pressure control, and insulin secretion

vitamin d deficiency

rickets and osteomalacia

vitamin d toxicity

most toxic of all vitamins

loss of appetite, nausea, thirst, and stupor

hypercalcemia

rickets

in children, seizures, growth retardation, and bones dont mineralize

osteomalacia

in adults, bone mineralization soft bones and increase fracture risk

supplement breast fed infants

have other impaired vitamin d absorption

deficiency of vitamin d results in development of

A and B

rickets and osteomalacia (NOT fracture of bone)

macronutrients

energy rich molecules providing cells with ability to perform normal cellular functions. building blocks for cellular biosynthetic pahtways

*carbs, fats, and proteins*

micronutrients

function in essential roles in metabolic processes. required in lower amounts but deprivation can lead to disease

*vitamins, organic compounds for coenzymes, or minerals (cofactors for enzymes)*

under nutrition

protein energy malnutrition (kwashiorkor, marasmus)

micronutrient deficiency (iodine, iron, vitamin deficiency)

hopsitalized patients (end stage liver/renal disease, cancer, HIV)

water function

fundamental of intra and extra cellular fluids

basic media for cell secretory events

how waste removal proceeds

how human’s lose water

respiraotry tract, skin, gastrointestinal, and kidneys

lose 0.5-1.0 literal per day thru resp and skin

water loss increase

6-8 times the basal level when body temp about 103.1\*F

dehydration causes

elevated body temp

hemorrhage, emesis, diarrhea

mutliple meds

loss of appetite (illness)

renal pathology

pituitary/adrenal hormone

water loss of 7-10% body weight results in

halluciantaions, shock, coma, and death

macronutrients required in large quantities

water

carbs

lipids

proteins or amino acids

micronutrients required in low levels

vitamins or minerals

vitamins

needed for function of enzymes

come from animal, plant, or bacteria

require activation

more than one function

coenzymes

bind to enzymes and promote activity

act as electron, atom, or molecule carries

involved in energy metabolism

b vitamins are

coenzymes

how many types of B vitamins

8

fat soluble vitamins

A, D, E, K

fat soluble about

carried with dietary fats via chylomicrons

stored in liver and adipose

less vulnerable to loss in handling and cooking

water soluble vitamins

b vitamins and vitamin c

water soluble about

absorbed directly into blood

stored in small quatitties

vulnerable to lsos in cooking and exposure to light and air

major contributing factor for vitamin c deficiency in US is __

both A and B

smoking and alcoholism

vitamin c function

reducing agent

hydroxylation of lysin and proline

bone formation

synthesis of carnitine and norepinephrine

iron absorption

antioxidant

humans do not have this enzyme

gluconolactone oxidase (last used in biosynthesis of ascorbate)

vitamin c deficiency

scurvy

spongy gums, loose teeth, bleeding from mucus, anemia

vitamin c synthesis of collagen/carnitine/tyrosin

hydroxylation of proline and lysin

vitamin c uses

collagen, carnitine, and tyrosin synthesis

neurotransmitter synthesis

improves cold symptoms 3-13%

vitamin c food sources

fruits like kiwi, oranges, grapefruit, and veggies like cauliflower, spinach, tomatoes, asparagus

smoking lowers serum levels

how vitamin c helps in conversion of peptide with c terminal glycine into c terminal amidated peptide and p-hydroxyphenylpyruvate into homogentisate?

as a reducing agent for cofactor copper (Cu)

B vitamins

group of 8 vitamins

important roles in cell metabolism

many foods contain

Thiamin (B1)

coenzyme for cleavage of carbon-carbon bonds and involed in amino acid and carbohydrate metabolism

thiamin pyrophosphate (TPP) → coenzyme in catabolism of sugars and AAs

obtain from diet

anti thiamin factors

enzymes that destroy thiamin

raw shellfish and freshwater fish, tea, coffee, some nuts, blueberries, red cabbage

thiamin food sources

yeast extract and pork most highly concentrate

found in wide variety of foods

mid thiamin deficiency

loss of appetite, constipation, nausea, mental depression, peripheral neuropathy, fatigue, irritability

Wernick-Korsakoff syndrome

moderate/severe deficiency in chronic alcoholics

characterized by apathy, loss of memory, and ophthalmoplegia (eye coordination loss)

beriberi

severe thiamin deficiency found in areas where polished rice is major diet

characterized by advanced neuromuscular symptoms like atrophy and muscle weakness

thiamin transporters

ThRr1 and ThTr2

present in intestinal brush border

ThTr2 present in

basolateral membrane of enterocytes and colonocytes

lower thiamine pyrophosphate in circulation

could increase ThTr2 expression in intestine

defects in SLC19A2 gene

recessive genetic mutation in ThTr1 coding gene leads to Rogers syndrom (megaloblastic anemia, deafness, and glucose intolerance)

onset of diabetes in non-type 1 in infants to adolescence

Riboflavin B2

precursor of cofactors flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN)

flavoproteins

wide range of redox potential that is essential for energy production and metabolism of fats, carbs, and proteins

riboflavin color

yellow or yellow-orange

riboflavin → FAD

riboflavin → flavokinase (form ADP) → FAD synthetase (ADP→PPi) → FAD

riboflavin food sources

milk, cheese, leafy green veggies, liver, legumes, tomatoes, almonds

riboflavin deficiency

not associated with a major human disease

called ariboflavinosis: includes dermatitis, cheilosis, and glossitits

can contribute to anemia with low iron intake

riboflavin involved in

iron mobilization

low iron→anemia

niacin B3

synthesized in body from EAA, tryptophan if diet adequate in tryptophan

niacin food sources

liver, chicken, beef, fish, cereal, peanuts, and legumes

niacin deficiency

results in the 4D’s

dementia, diarrhea, dermatitis, and death

pellagra

niacin dificiency → skin is hyperpigmented

malabsorption in chornic alcoholism

anti-tuberculosis drug, isoniazid that decreases PLP-dependent synthesis of niacin from tryptophan

treated with mercaptopurine, cancer treatment drug, NAD phosphorylases

pantothenic acid B5

used in synthesis of CoA

CoA importance

energy metabolism for pyruvate to enter TCA cycle as acetyl-CoA and for alpha ketoglutarate to be transformed to succinyl-CoA

also in biosynthesis of many compounds like fatty acids, cholesterol, and acetylcholine