Nutrition Exam 3

Free Radicals

Molecules with one or more unpaired electrons
-created when oxygen reacts with body
-also produced by UV, air pollution, tobacco
*Steals an electron to gain stability which damages fatty acids in membrane, protein, DNA/RNA
-impair cell functions and imflammation occurs

Antioxidants

ends chain reaction of radicals by donating an electron and remaining stable
-as we age defense mechanism less effective
-leads to disease states

anitoxidant vitamins

Vitamin E, Beta Carotene, Vitamin C

Vitamin E

defends body lipids- cell membrane, lipoprotein, nervous tissues

Beta Carotene

defends lipid membranes

Vitamin C

protects other tissues- skin and fluid of blood

Cancer

cellular DNA damaged, causing cancer
-not always by free radicals
-anitoxidant may decrease risk

Heart Disease

oxidative stress contributes to hearth disease and atherosclerosis

Antioxidants in diet

fruits and vegetables are better sources than supplements

Phytochemicals

Chemicals in plant-based foods that are not nutrients but that have effects on the body.
-defend against cancer
-Protect DNA

EX: soybeans, flaxseeds, tomatoes

Functional foods

contain bioactive compounds
-potentially beneficial effect on health when consumed regularly

Flavonoids and Plant Sterols

help defend against heart disease

Vitamins

do not yield energy but do assist with the process

Bioavailability

the rate at and the extent to which a nutrient is absorbed and used

What does bioavailability depend on?

-Efficiency of digestion and transit time in the GI tract
-Prior nutrient intake and nutrition status
-Method of food preparation
-Source of the nutrient
Other foods consumed at the same time

Toxicity of Vitamins

Risk of symptoms of toxicity increase as one goes over the UL

water soluble vitamins

B and C (hydrophilic)
-removed in urine

Fat soluble vitamins

A, D, E, K (hydrophobic)
-require transport protein
-stored in fatty tissues and liver

B vitamins

Serve important roles in metabolism
Make up a portion of multiple coenzymes

coenzyme

work with an enzyme to facilitate the enzymes activity

Thiamin (B1)

Part of coenzyme TPP
-assists with energy metabolism, participates in conversion of pyruvate to acetyl CoA
-special site of membrane of nerve cells
-comes from grains and pork
-cooking can destroy

Recommended Thiamin Intake

Men: 1.2mg
Women: 1.1

Thiamin deficiency

-people who derive most of their kcal from empt food/beverage

Beriberi

thiamin deficiency
-WET= cardiovascular
DRY= nervous system

Riboflavin (B2)

part of coenzyme FMN and FAD
-assists energy metabolism
-can accept and donate 2 hydrogen
-milk, grains, green leafy vegetables
-UV destroys, cooking does not

Riboflavin Recommendations

Men: 1.3 mg/day
Women: 1.1 mg/day

Riboflavin deficiency

Inflammation of the mouth, skin, and eyelids, GI tract

Niacin (Vitamin B3)

metabolism of glucose, fat and alcohol
-protect neurological degeneration
-meat, poultry, fish, grains, legumes, vegetables
-can withstand higher cooking times
-leaches out into water

Recommended Niacin Intake

16 mg NE/day for men
14 mg NE/day for women
-can make from tryptophan (60mg)- 1mg

Niacin deficiency

pellagra: dermatitis, diarrhea, dementia, death

Niacin Toxicity (UL)

UL= 35mg/day
-can produce HDL

Biotin

coenzyme in gluconeogensis, fatty acid synthesis, and breakdown of amino acid/ fatty acid
-delivers CO2
-protects neurological degneration
-grains, soybeans, egg yolks

recommended biotin intake

AI for adults: 30 mcg/day
-produced by GI bacteria

Biotin deficiency

-unlikely
-high consumption of raw egg whites (2 dozen or more per day) may cause deficiency

Panthothenic acid

part of coenzyme A, used in energy metabolism
-synthesis of lipids, neurotransmitters, steroid hormones and hemoglobin
-meat, poultry, egg yolk, grains, vegetables
-loses in freezing, canning, refining

Recommended Pantothenic Acid Intake

5mcg/day, no UL

Vitamin B6

amino acid and fatty acid metabolism
-requires Riboflavin to convert B6 to PLP
-assists in making red blood cells
-stored in muscle
-meat, poultry, fish, soy, cereals, legumes, fruits, vegetable

Vitamin B6 Recommendations

RDA for adults: 1.3 mg/day
UL is 100 mg/day

Vitamin B6 deficiency

depression and confusion
-alcohol destroys Vitamin B

-people with poor kidney function, autoimmune disorders and alcohol dependence are more at risk

Folate

coenzyme involved in metabolism
-helps synthesize DNA
-key during pregnancy
-comes from legumes, fruit, dark gree leafy vegetables, grain

recommended folate intake

400 mcg/day
-UL is 1000 mcg

Activation of folate

requires Vitamin B12 to activate

dietary folate equivalents (DFE)

the amount of folate available to the body from naturally occurring sources, fortified foods, and supplements, accounting for differences in the bioavailability from each source

Folate deficiency

anemia and GI tract deterioration
Spina bifida
-neural tube defects

Vitamin B12

closely related to folate; both depend on each other for synthesis of DNA, RNA
-maintains sheath around nerve fibers
-milk, fish, grain, soy, animal

Recommended B12 intake

2.4 mcg/day

Vitamin B12 deficiency

anemia and impaired cognition
-vegans are more at risk

Choline

essential nutrient that helps support development of brain and spinal cord during pregnancy
-milk, eggs, peanuts

recommended choline

Men: 550 mg/day
Women: 425 mg/day
UL: 3500 mg/day

Vitamin C (absorbic acid) function

antioxidant that decreases effects pf free radicals
-cofactor to form collagen
-enhances iron absorption
-citrus, berries, broccoli, peppers

Recommended Vitamin C

men: 90 mg/day
women: 75 mg/day

UL: 200mg/day

Scurvy

Vitamin C Deficiency

- *Bleeding Gums*
- *Joint Pain*
-internal bleeding

Vitamin C toxicity

increased kidney stone risk, can interfere with medical test

Fat soluble Vitamins

require bile to be digested and absorbed
-excess stored in liver and adipose tissue

Vitamin A

retinol, retinal, retinoic acid, beta carotene
-maintains clear cornea
-protects skin from sun damage
-support reproduction and regulate growth

Beta Carotene: Dark green leafy vegetables, deep orange fruit/ vegetable

Vitamin A recommendations

RDA for men: 900 mcg/day, RDA for women: 700 mcg/day UL:3000mcg/day

Vitamin A deficiency

night blindness

Vitamin A toxicity

yellowing of skin, suppressed bone building, birth defects

Vitamin D

D2- from plant foods
D3- from animal foods and UV rays that convert in skin
- hormone, bone health, protect against diseases
-come from milk, margarine, butter, fatty fish, egg yolk

recommended vitamin D

15 mcg/day
70+ = 20mcg
UL= 100 mcg

Vitamin D deficiencies

causes rickets- bowed legs
-less bone mass
-osteoporosis
-older adults more affected

Vitamin E functions

antioxidant, protects cell membranes
-margarine, vegetable oil, salad dressing

Vitamin E Recommendations

RDA: 15 mg/day
UL: 1000 mg/day

Vitamin E deficiency

neuromuscular problems, hemolytic anemia

Vitamin E toxicity

May interfere with blood clotting action of Vitamin K

Vitamin K

primary function is blood clotting
-synthesis of blood clots
-bacteria in GI make vitamin K
-liver, dark vegetables, vegetable oil

Recommended vitamin K

men: 120 mcg/day
women: 90 mcg/day

Vitamin K deficiency

newborns cannot make vitamin K since GI is sterile
-antibiotics kill bacteria in intestine

Reasons for Dietary Supplements

- Prevent or correct deficiencies
- Nutrient deficiencies
- Low calorie intake
- Reduce disease risks
- Individuals who omit certain foods
- Meet needs during life stages where needs are increased

Arguments against dietary supplements

toxicity; provide individuals with a false sense of security; marketing is often misleading; evidence is insufficient for most dietary supplements

regulation of dietary supplements

• Regulated by the FDA
- Defined by the Dietary Supplement and Health Education Act of 1994
• What does DSHEA say?
- Labeling is required
- Labels may make health claims but cannot be brand
specific
- Labels may claim to diagnose, treat, cure or relieve
common symptoms but not a disease
- All must include an FDA disclaimer

complementary medicine

treatment that is considered unconventional, used along with conventional medicine, insufficient evidence of purported effects

alternative medicine

treatment that is considered unconventional, used in place of conventional medicine, insufficient evidence of purported effects

Water

60% of adults body weight
-75% of lean tissue and

Functions of water in the body

-Carries nutrients and waste products
-Participates in metabolic reactions
-Acts as lubricant and cushion for joints, eyes, spinal cord, and the amniotic sac in pregnancy
-Regulation of body temperature
-Maintains blood volume

intracellular fluid

fluid within cells
-high in potassium
-2/3 of water

Extracellular fluid

fluid outside the cell
-high in sodium
- 1/3 of bodies water

Electrolytes

salts that dissolve in water and break apart into ions
-electrolytes attract water

Inadequate water intake

blood becomes concentrated, mouth becomes dry, hypothalamus initiates drinking behavior, urine dark yellow

excessive water intake

Stomach expands
Receptors send signals to stop drinking fluids
May cause water intoxication
Rare—dilutes sodium concentration of blood

sensible water loss

water loss that is noticed by a person, such as through urine output and visible sweating

insensible water loss

the loss of water not noticeable by a person, such as through evaporation from the skin and exhalation from the lungs during breathing

Daily losses of water

2,500 mL

water recommendations

Men: 3.7 L/day (16 cups)
Women: 2.7 L/day (12 cups)

Sodium

primary electrolyte in extracellular fluid
-maintains fluid balance
-processed foods, table salt, some natural foods

RDA for sodium

19-50 years old (1500mg)
UL for adults (2300 mg/day)

sodium deficiency

usually vomitting, diarrhea, or sweating removes sodium
-may cause crams and confusion

Sodium and health

Hypertension:
-Sodium thought to raise blood pressure
-Salt (sodium chloride) has a greater effect on blood pressure
-High intakes of salt can cause irreversible damage to blood vessels
-Blood pressure increases in response to excess salt intake
Some are more salt sensitive than others
Individuals with hypertension
African Americans
Adults over 40yo

DASH Dietary Pattern

Chloride

major anion in extracellular fluid
-maintains fluid and electrolyte balance
-part of HCl

RDA for chloride

2300 mg/day
UL-3600 mg/day

Potassium

main intracellular cation
-maintains fluid and electrolyte balance

Potassium deficiency

high blood pressure, salt sensitivity, kidney stones, high burn turnover

-toxicity can cause kidneys to increase excretion

-meats, milk, fruit, vegetables, grains, legumes

potassium recommendations

4700 mg/day

Calcium

most abundant mineral in the body
-bone and teeth, bodily fluids
-participate in blood clotting and activates proteins

RDA for calcium

Adults: 1000 mg/day
Over 70 men: 1200
Women over 50: 1200
adolescent to 18: 1300

UL: 2500

Osteoporosis

results from inadequate calcium intake

Magnesium

found in bones, muscles and tissues
-helps bone health
-important in metabolism

-comes from nuts, seeds, whole grains, vegetables, seafood, chocolate

RDA for magnesium

men: 400
women: 310

UL: 350 mg

Magnesium Deficiency

May affect bone metabolism
Inflammation leading to heart disease, hypertension, and DM
May contribute to high blood pressure

Phosphorous

second most abundant mineral in the body
-bones, teeth, cells
-assists in energy metabolism
, activates B-vitamins
-phospholipids

-meat,fish, poultry, eggs, milk