JMU Nutrition 280 Theimer Final Exam m

Vitamin

essential organic compounds needed in small amounts

Divided into 2 groups based on

solubility in water or fat

Water soluble vitamins

B and C

Fat soluble vitamins

A, D, E, K

Food groups that lack B12?

Grains, vegetables, fruits

Food groups low in vitamin C?

Grains, dairy, protein

Vitamin absorption occurs mainly in

the small intestine

Compound that's the basis for the RDA for vitamin E?

Alpha-tocopherol because it's the only form of vitamin E that can be used by the body

Absorption of water-soluble vitamins

transport system -> directly into blood

Absorption of fat-soluble vitamins

micelles -> chylomicrons -> lymph -> blood

All B vitamins

act as coenzymes

Antioxidant vitamins?

Provitamin A (inactive), C, E

B vitamins

do NOT directly provide energy

a deficiency affects every cell in the body

Thiamin

helps breakdown glucose for energy

needed to convert pyruvate into acetyl-CoA

needed for synthesis of NTs and ribose+deoxyribose

Beriberi

the thiamin-deficiency disease; characterized by loss of sensation in the hands and feet, muscular weakness, advancing paralysis, and abnormal heart action

Riboflavin

supports vision and skin health

helps other B vitamins to convert to active forms

part of ATP making coenzymes

Vitamin C is also known as

ascorbic acid

Vitamin C helps in the absorption of

iron, calcium, folate

Vitamin C deficiency

Scurvy

Choline

not a vitamin

it's a water soluble substance

essential nutrient

needed to make ACH

Fat soluble vitamin A types

Retinoids and carotenoids

Retinoids

pre-formed, active vitamin A

found in animals foods

more readily absorbed

Carotenoids

found in plant foods

natural pigments

can either end up active or remaining a precursor

Beta-carotene

most potent vitamin A precursor

Vitamin A is stored in the

liver

Vitamin A functions

gene expression and cell differentiation

vision

Vitamin A deficiency

xerophthalmia

Vitamin D

can be made by UV light in skin

Use of sunscreen

SPF 15 decreases synthesis of vitamin D by 99%

Vitamin D function

Regulation of calcium and phosphate metabolism

Vitamin D deficiency in kids

Rickets

Vitamin D deficiency in adults

osteomalacia

Osteoporosis

loss of total bone mass

Cheilosis

a disorder of the lips characterized by crack-like sores at the corners of the mouth

Vitamin E

antioxidant

protects from oxidative damage

by donating one electron

oxidant function can be restored

What nutrient gives its electron back to vitamin E?

Vitamin C

Populations at risk of vitamin E deficiency?

premature infants

lack of vitamin E makes cell membranes unprotected and break down

Vitamin E is more

naturally-occurring

Absorption of vitamin E

incorporated into micelles

Storage of vitamin E

fatty tissue, liver, and muscles

Supplemental vitamin E only provides

1/2 as much vitamin E as the natural form

Vitamin K

main role in role clotting

also involved in bone formation, breaking down, cell growth

Fibrin

insoluble, fibrous protein that forms the solid clot; traps blood cells and platelets

Vitamin K can be used to fight

osteoporosis

Vitamin K is used by body

more rapidly than other fat-soluble vitamins

Can body make vitamin K?

bacteria in the large intestine can make about 1/2 amount of vitamin K we need

Groups at risk of vitamin K deficiency

newborns- intestine is sterile

long term antibiotic usage

Water is

essential nutrient for life

% of person's body weight by water

~60% (50%-70%)

Intracellular fluid

2/3 of water in body. found inside cells. used for cell reactions.

Extracellular fluid

1/3 of water in body. found outside cells. helps moving materials from cells

Interstitial fluid

surrounds the outside of cell and doesn't circulate

Plasma fluid

part of blood and lymph contains no cells

Transcellular fluids

smallest component of the three types

Osmosis

unassisted diffusion of water across the cell membrane

How body gains water?

primarily digestive tract

metabolic by-product of reactions

How body loses water?

urine and feces

evaporation

sweating

vomiting and diarrhea

1st sign of dehydration

being thirsty

Functions of water

universal solvent

serves as a transporter

medium for reactions

participates in chemical reactions

How does the dilation of blood vessels near skin help it cool?

increases blood flow near surface of skin

heat can be released

Survival

8 weeks without food, few days without water

When you feel thirsty?

may have lost up to 16 oz. of water or 1/2% of your body weight

Hyponatremia

low sodium in the blood

Amount of water needed per day

Males: 3.7 liters/day

Females: 2.7 liters/day

About 80% of AI for water is achieved from fluids, 20% is from food

Major minerals

require > 100 mg/day

Trace minerals

require < 100 mg/day

iron, zinc

Food groups that provide the greatest variety of minerals?

Grains and protein

Bioavailability

the extent to which the body can absorb and use a nutrient

Minerals in animals products

are more readily absorbed than plant products

Phytates

found in whole grains, bran, and soy products

binds with minerals and reduces absorption

Yeast Benefits

breaks down phytates, making minerals more available

Tannins

found in tea and some grain

hinder iron absorption

Oxalates

found in spinach, beet greens, and chocolate. Interfere with absorption of calcium and iron

Minerals with the same electric charge can compete for absorption in the digestive tract

Sodium (major mineral)

most abundant positively charged extracellular ion

helps maintain fluid and acid/base balance

needed for muscle contractions and nerve transmission

Potassium (major mineral)

principle positively charged intracellular ion

helps maintain cell's integrity

needed for fluid balance and nerve transmission

Low potassium intakes

raises blood pressure

accelerates calcium loss from bones

Chloride (major mineral)

principle negatively charged extracellular ion

helps maintain fluid/electrolyte and acid/base balance and acidity of stomach

main source from salt

Electrolyte functions

help regulate fluid balance

generate and conduct nerve impulses

Kidneys regulate electrolyte balance by

conserving water and regulating blood pressure

UL for sodium

2,300 mg daily

Amount of salt we get from food

over 3/4 is added

Increased sodium intakes results in

high blood pressure (silent killer)

DASH eating plan

Dietary Approaches to Stop Hypertension

Calcium (major mineral)

most abundant mineral in the body

99% found in bones/teeth

1% found in body cells and fluids

Bones and teeth

release calcium when blood calcium levels drop

Peak bone mass

achieved between ages 16-30

Two hormones that regulate blood concentration levels

parathyroid hormone and calcitonin

Phosphorus (major mineral)

2nd most abundant mineral in the body

85% found as hard mineral crystals in bone/teeth

helps extract energy from CHO, protein, fat

Magnesium (major mineral)

barely qualifies as a major mineral

50%-60% found in bones

needed to make new bone

stabilizes ATP structure, needed in every ATP reaction

Sulfur (major mineral)

part of proteins in the body

antioxidant

needed for energy metabolism

role in acid/base balance

Iron (trace mineral)

transport oxygen and electrons

component of hemoglobin and myoglobin

Heme-iron

iron containing part of hemoglobin and myoglobin in protein, more readily absorbed

Nonheme iron

found in plants and meats

Copper (trace mineral)

component of connective tissue (like collagen)

component of antioxidant enzymes

Zinc (trace mineral)

most abundant intracellular trace mineral

role in gene expression and protein making

needed in making heme-iron

acts as an antioxidant

Selenium (trace mineral)

component of antioxidant enzyme that helps save vitamin E

activates thyroxine that regulates BMR

Iodine (trace mineral)

3/4 of body's iodine found in thyroid gland

makes 2 hormones that regulate BMR and body growth and development

Goiter

iodine deficiency

enlarged thyroid gland