Human Nutrition Exam 3: Chapters 9, 10, 11, 12, & 13

Generic properties of micronutrients

-organic compounds

-do not provide energy

-are not building blocks

-required in small amounts

-must be obtained through diet

At least 2 types of vitamin functions

-help convert energy in fat, carbs, and protein into ATP (coenzyme)

-antioxidants

-regulate metabolism

-promote growth and reproduction

4 fat soluble vitamins

-A

-D

-E

-K

Vitamin A

-promotes good vision

-promotes healthy skin

-promotes strong immune system

-promotes reproduction

-works as antioxidant

-risk of deficiency is the most common in the world

-large problem in developing countries

-risk of infectious diseases

-night blindness -> blindness

-death

-keratinization

-foods rich in Vitamin A

-liver, milk, eggs, cheese, carrots, spinach, sweet potatoes

-precursor= beta-catotene

-stored mainly in liver

-absorbed in small intestine

Vitamin D

-"sunshine vitamin"

-excreted through feces and a little with urine

-body synthesizes from a form of cholesterol upon exposure to UV light

-active form is calciferol

-promotes bone growth

-may prevent some cancers, diabetes

-potentially reduces risk of autoimmune disorders

-may regulate BP

-foods rich in Vitamin D

-oily fish, fortified milk, egg yolks

Vitamin E

-active form is Alpha-Tocopherol

-absorbed with bile salts and micelles

-90% is stored in adipose tissue

-excreted through bile and feces

-powerful antioxidant

-anticoagulant

-foods rich in Vitamin E

-vegetable oils, avocados, nuts, seeds, broccoli

-deficiency is rare but chronic deficiency can cause nerve problems and muscle weakness

Vitamin K

-K1=green plants

-K2=bacteria in intestine

-K3=synthetic form

-mostly absorbed in jejunum

-10% produced by bacteria in colon

-packaged in chylomicrons then transported to liver

-stored mainly in the liver

-promotes blood clotting

-promotes strong bones

-foods rich in Vitamin K

-green leafy vegetables, vegetable oils, maragine

-deficiency is rare but may cause hip fractures in older age

-babies are born with a sterile GI tract, they are given a single dose shot of Vitamin K

Alternative name for Thiamin

Vitamin B1

Alternative name for Riboflavin

Vitamin B2

Alternative name for Niacin

Vitamin B3

Alternative name for Folate

Vitamin B9

Alternative name for B12

Cobalamin

Alternative name for Vitamin C

Ascorbic Acid

Alternative name for Vitamin D

Cholecalciferol

Alternative name for Vitamin A

Retinals

Alternative name for Vitamin E

Tocopherols/Tocotrienols

Thiamin/Vitamin B1

-assists in energy metabolism; part of coenzyme (TPP)

-destroyed in basic solutions

-absorbed in jejunum

-transported through blood; excreted through urine

-foods rich in Thiamin

-whole grain foods, lean pork, enriched/fortified cereals

Riboflavin/Vitamin B2

-coenzyme in energy metabolism

-stable during cooking; destroyed by light and radiation

-absorbed in small intestine

-attached to proteins in foods, released in presence in HCl

-participates in beta oxidation and oxidation reduction

-foods rich in Riboflavin

-milk, yogurt, fortified/enriched cereals, grains

Niacin/Vitamin B3

-involved in metabolic reactions

-stable in foods; not destroyed by heat or UV

-can leach if food is cooked or soaked in water

-absorbed in the small intestine

-circulates through the blood to the liver

-keeps skin cells healthy and digestive

system functioning properly

-role in cholesterol metabolism

(in therapeutic doses):

-lowers total cholesterol in the blood

-lowers triglycerides

-raises HDL cholesterol

-foods rich in Niacin

-meats, fish, poultry, enriched and fortified

grains and cereals

Folate/Vitamin B9

-folate is found in many natural foods

-folic acid is the synthetic form added to foods and in supplements

-most folate in foods is in the polyglutamate form

-folate is destroyed with exposure to heat and light; raw foods have more folate than cooked foods

-absorption= all but one glutamate is removed to form monoglutamate during digestion

-in the small intestine, 5-methyl-tetrahydrofolate is

formed and transported to the liver

-active form: Tetrahydrofolate (THF)

-Vitamin B12 is needed to activate folate

-the liver incorporates excess folate into bile that

is then is sent to the gallbladder and GI tract.

Folate can be reabsorbed

-converts vitamin B12 to coenzyme form

-assists in neural tube development to prevent:

-neural tube defects

-anencephaly

-spina bifida

-critical in pregnancy

-may have a role in cancer prevention

-role in protecting against heart disease

-foods rich in folate

-dark green leafy vegetables, legumes, seeds, enriched pasta, rice, breads, cereals, and liver

-no toxicity from natural forms, but from supplements

Vitamin B12/Cobalamin

-contains the element cobalt(metal)

-Vitamin B12 and folate depend on each other for activation

-digestions and absorption requires intrinsic factor

-stored mostly in the liver

-excreted through the bile and urine

-deficiency can take years to develop

-plants and animals cannot synthesize cobalamin, only microorganisms

participate in energy metabolism

and DNA and RNA synthesis

-activates folate

-synthesis of new cells, especially red blood cells

-maintains myelin sheath of nerve tissue

-catabolism of amino acids and fatty acids for energy metabolism

-found mostly in animal products

-most deficiencies happen due to inadequate absorption not poor intake

-vegans=low intake

-absorption decreases with age

-microwave cooking reduces the active form by 30-40%

-deficiencies:

-pernicious anemia

-anemia of folate deficiency - Macrocytic anemia

Vitamin C/Ascorbic Acid

-humans (and primates) lack the enzyme to make vitamin C

-absorption through small intestine; absorption decreases 50% with intakes > 1 gram

-excreted through kidneys

-not stored in the body

-vulnerable to heat and oxygen

-used as antioxidant by food manufacturers

-not a coenzyme but is necessary for important metabolic processes

-antioxidant

-defends against free radicals

-loses electrons easily

-role in collagen formation

-scurvy

-healthy skin

-acts as antioxidant

-enhances iron absorption

-cofactor in many other reactions

-prevention and treatment of common cold

-linus Pauling's theory

-slight but consistent shortening of cold duration

-deactivates histamine

-collagen is an extracellular protein. It is the main component of connective tissue; collagen is the most abundant protein in mammals, making up

from 25% to 35% of the whole-body protein content

-raw fruit and vegetables

How much water a person has

-an average healthy adult is 45-75% water

-males have more water in their bodies than women do

-muscle is 65% water

- fat is 10-40% water

Functions of water

-water is the most abundant substance in the human body

-water is the most essential nutritional compound

-without it, one could only survive a few days

-universal solvent

-helps transports dissolved nutrients and other substances throughout the body

-maintains body temperature

-absorbs and released heated generated by the body

-evaporation takes away heat

-lubricants for eyes, joints, mouth, intestinal tract

-provides a protective cushion

-bathes certain organs with fluids

-during pregnancy the fetus is surrounded by amniotic fluid

-participates in hydrolysis and condensation reactions

-plays a role in acid-base balance

Osmosis

-the movement of water through a semi-permeable membrane into a solution of higher concentration

-passive, no ATP needed

-this restores balance to the concentration of both sides of the cell membrane

-isotonic=same concentration of dissolved particles (0.9% saline) (IV fluids)

-hypertonic=higher concentration

-hypotonic=lower concentration

-electrolytes attract water

-electrolyes predominantly OUTSIDE cell:

-sodium

-chloride

-calcium

-electrolytes predominantly INSIDE cell:

-potassium

-phosphate

-magnesium

Sodium-Potassium Exchange Pump

-is a transport protein that moves Na+ and K+ ions

against a concentration gradient;cells expend energy

-maintains normal electrolyte concentrations

-three Na+ ions are exchanged for two K+ ions

-keeps the cell from swelling and bursting

-aids in electrical conduction in nerve and muscle cells

-aids in nutrient absorption

-proteins regulate fluid balance

People more vulnerable to dehydration

-seniors and infants

-endurance athletes

-patients with diabetes

-patients with diarrhea

-heavy drinkers/alcoholics

Foods that are diuretics

-alcohol

-caffeine

-salt

-celery

-ginger

-garlic

How water balance is maintained

-minimum of 500mL/daily

-by electrolytes and hormones

Main extracellular osmotic ion

Sodium

Main intracellular osmotic ion

Potassium

General properties of minerals

-inorganic elements essential to the nutrition of humans

-always retain chemical identity

-stable;cannot be destroyed by heat, UV, oxygen, acid

-do not provide energy

-they are not building blocks

-help chemical reactions take place in cells (cofactors)

-help maintain fluid balance in the body

-work with the immune system, helps muscles contract

Difference between trace minerals and major minerals

Trace Minerals

-micronutrients

-need to consume less than 20mg per day

-the body contains less than 5g total

-includes

-Iron

-Chromium

-Zinc

-Iodide

-Copper

-Manganese

-Selenium

-Fluoride

-Chromium

-Molybdenum

Major Minerals

-macronutrients

-need to consume more than 100 mg per day

-at least 5g of the mineral in the body

-includes

-Calcium

-Sodium

-Potassium

-Chloride

-Phosphorus

-Magnesium

-Sulfur

What is Osteoporosis

-a condition whereby the bones are porous and less dense, increasing the risk of fractures (2 types)

-Type 1= results from lowered estrogen levels women experience during menopause; rapid bone loss

-Type 2= occurs in both men and women, slow loss over time due to aging

-becomes apparent later in life

-develops earlier without symptoms

-one of the most prevalent diseases in US

What is the DASH diet

-Dietary Approaches to Stop Hypertension

-balanced diets that are low in fat, saturated fat, cholesterol, and sweets

-high in whole grains, fruits, vegetables, legumes and low fat dairy products

-individuals who follow this diet, experienced a significant reduction in blood pressure

-lowering the amount of sodium consumed in the DASH diet lowers blood pressure more

What foods are high in sodium

-cheese

-canned goods

-cured meats

-frozen meals

Health issues associated with excess of sodium

-hypertension

-hypernatremia

Toxicity in Vitamin C

-toxicity= consuming > 3,000 mg can cause GI distress and diarrhea

-interference with medical regimens

-high doses not recommended with certain medical conditions (anticlotting medications)

Deficiency in Vitamin C

-deficiency:

-scurvy

-bleeding gums

-wounds won't heal

-rough rash

-prevented with 10 mg of vitamin C per day

Deficiency/Toxicity in Niacin/Vitamin B3

-deficiency= Pellagra (disease of the four Ds)

-dermatitis

-diarrhea

-dementia

-death

-caused deaths in the U.S. South in the early

1900s, where many people subsisted on low protein diet centered in corn

-no toxicity from natural sources; but from supplements or drugs

-niacin flush

-potential health benefits of large doses of nicotinic acid

Deficiency in Folate/Vitamin B9

-deficiency:

-neural tube defects

-supplement use during pregnancy

-one month before conception, through first trimester

-interferes with normal red blood cell division

-macrocytic anemia

Toxicity/Deficiency in Riboflavin

-deficiency is rare but can cause inflammation of membrane

-ariboflavins (flu-like symptoms)

-no toxicity; excessive amounts are excreted in urine

Deficiency in Vitamin D

-deficiency is quite common

-calcium deficiency

-Rickets

-Osteomalacia (adult Rickets)

-Osteoporosis

-older age is more likely to have deficiency due to reduced ability to make/activate Vitamin D, they drink less milk and they spend more time indoors

Deficiencies in Thiamin/Vitamin B1

-no toxicitiy

-deficiency= most common in malnourished and alcoholics

-Beriberi= loss of appetite, weight loss, confusion

-Wernicke-Korsakoff Syndrome= chronic alcohol abuse