Nutrition Exam 2

•Antioxidant Vitamins -

-Beta-carotene, Vitamin C, Vitamin E

•Free Radicals

-Chemical substances (usually oxygen or hydrogen) that are missing an electron -Absence of an electron makes the substance reactive and prone to oxidizing nearby atoms or molecules by stealing an electron from them -Damages DNA, cell membranes, and other cell components

Niacin (B3) major functions

-Coenzyme in oxidation-reduction reactions •Carbohydrate and fat metabolism •DNA production -Keeps skin cells healthy and digestive system functioning properly - •In therapeutic doses (generally high doses) -Lowers total cholesterol in the blood -Lowers triglycerides -Raises HDL cholesterol

Niacin (B3) Toxicity

-None known from normal dietary intake -Excess supplements and/or too many fortified foods will cause overdose. •Reddish coloring of the face, arms, and chest •Nausea, vomiting •Heartburn •Liver toxicity Raised blood glucose levels

Vitamin B6 or Pyridoxine major functions

-Protein metabolism -Protein synthesis -Fat metabolism -Glycolysis -Red blood cell synthesis -Keeps the immune and nervous system healthy

Antioxidant functions

-Scavenge "free radicals" •oxidative products of metabolism, radiation, and toxin exposure •Free radicals are blamed for cancer, bronchitis, heart disease, cataracts, Alzheimer's, Parkinson's and premature ageing • -Antioxidants stabilize molecules or repair them by giving an electron -Get antioxidants and phytochemicals from the diet instead of supplements

•Other Antioxidants -

-Selenium - -Flavonoids, Carotenoids -Phytonutrients

Antioxidants are inhibitors of

1.inflammation 2.Preventers of infectious disease

How many vitamins are there?

13

Vitamin B12 RDA

2.4 mcg/day •Vitamin B12 supplements/injection maybe necessary for some people... •Adults > 50 yrs. -Absorption decreases with age -Low intrinsic factor •(caused by aging) •Gastric bypass patients •Vegan Athletes

What are the fat soluble vitamins?

A, D, E, K

Riboflavin (B2) Deficiency

Ariboflavinosis - cells in tissues lining the throat, mouth, tongue and lips becomes inflamed or swollen -Sore throat -Stomatitis -Glossitis -Cheilosis •Reduces conversion of vitamin B6 to its active form •Alters iron metabolism and the synthesis of hemoglobin

Phytochemicals

Chemical substances in plants which likely perform important functions in the body

Choline

Choline is a nitrogen-containing compound found in foods and made by the body from the amino acid methionine. -Not a TRUE vitamin but an important co-enzyme -Needed for synthesis of neurotransmitter acetylcholine and phospholipid lecithin -Important for cognition and mental wellbeing Food Sources: milk, eggs, peanuts, liver AI: Women 425 mg/d, Men 550 mg/d

Folic Acid DRI and UL

DRI: 400 mcg/day UL 1000 mcg/day

____ soluble vitamins are more stable?

Fat soluble

Vitamins in the Food Groups: Fruits

Folate Vitamin C

Vitamins in the Food Groups: Vegetables

Folate vitamin A,C,E

Vitamins in the Food Groups:Grains

Folic Acid Niacin Vitamin B6,B12 Thiamin Riboflavin

Vitamin C or Ascorbic acid: function and sources

Function: •Collagen synthesis •Antioxidant Helps to iron absorption Sources: Fruits, vegetables, potatoes, bell peppers, strawberries, citrus

Vitamin B3 (Niacin)

Function: Conversion of carbohydrate, protein and fat to energy, NAD Sources: Meats, grains, beans, nuts, dairy products, coffee, potatoes Additional Source: Can be synthesized from amino acid tryptophan • 60 mg tryptophan = 1 mg niacin

Vitamin B12 or Cobalamin: Functions and sources

Functions: •Nerve tissue, red blood cell development •Folic acid metabolism prevent pernicious anemia •Maintains myelin sheath of nerve tissue •Catabolism of amino acids and fatty acids for energy metabolism Sources: •Meats, seafood, eggs, dairy products, fortified cereals, supplements.

Food sources of Vitamin E

Grains, protein, oils, fruits

•Fat-soluble vitamins are generally _________ bioavailable than water-soluble vitamins

LESS

Vitamins from animal foods are generally _______bioavailable than those in plant foods

MORE

Vitamins in the Food Groups:Protein

Niacin Thiamin B6,B12

Are Serious vitamin deficiency diseases common in the US?

No

Are more vitamins always better?

No

Do vitamins themselves provide energy?

No

Vitamins are an

Organic carbon contain substances that have a variety of function in the human body.

Niacin (B3) Deficiency

Pellagra (disease of the four Ds) -Dermatitis -Diarrhea -Dementia Death

Vitamin C or Ascorbic acid: RDA

RDA: Men 90 mg/day, Women 75 mg/day Athletes 200 mg/day Deficiency: Scurvy Need 10-15 mg/day to prevent scurvy Toxicity: ~2 g/day may be toxic

Vitamins in the Food Groups:Dairy

Riboflavin A,B12,D

FoodSources of Vitamin B6

Vegetables, fruits, proteins

Food Sources of Folate

Vegetables, grains

what food sources are high in vitamin A

Vegetables, protein

FoodSources of Thiamin (B1)

Vegies, grains, proteins

Vitamins and behavior

Vitamins Participate in reactions that affect behaviors -Reduced attention span, poor appetite, irritability, depression, or paranoia often precede the physical signs of vitamin deficiency

spina bifida

a congenital defect that occurs during early pregnancy when the spinal canal fails to close completely around the spinal cord to protect it - A specific type of neural tube defect -FORMS OUTSIDE OF THE BODY

Majority of phytochemicals function as

antioxidants

•Water-soluble vitamins Absorbed with water and enter directly into the

blood stream

•Fat-soluble vitamins Are absorbed in the

duodenum

most water soluble vitamins are absorbed in the

duodenum and jejunum and are not stored in the body

Some vitamins act as important co-enzymes converting fats, carbohydrates, proteins, and alcohol to

energy

Vitamins are absorbed intact and perform numerous____

essential functions

Dietary Reference Intakes include tolerable upper intake limits (UL) for most vitamins to prevent

excess

While many "energy" drinks are fortified with B vitamins and claim to increase energy, they do not do this by themselves. B vitamins are

involved in the pathways that break down macronutrients into a usable form of energy. Furthermore, an excessive amount of B vitamins does not increase the production of energy from macronutrients.

Food sources of vitamin D

protein and dairy

Biotin and pantothenic acid deficiencies only occur with

severe food restriction or starvation and there is no know toxicity.

All vitamin absorption takes place in the

small intestine

Vitamins Cannot be synthesized in ample amounts in

the body

Vitamin B6, Niacin and Vitamin C can be

toxic in high doses

Chemical structure of each vitamin is

unique

•Excess intake of water soluble vitamins are excreted through ______ and therefore it is important to consume adequate amounts daily.

urine

vitamins play roles in preventing

various diseases from birth defects to cataracts, heart disease and cancer

Food sources of vitamin K

vegetables

Food Sources of Riboflavin

vegetables, grains, dairy

•Due to water solubility, these vitamins "wash out" of the body in one to several days except for _________; it can be stored up to one year in the liver, however there are no know toxicities to this vitamin

vitamin B12

Scurvy

will cause loss of collagen in the gums of the teeth and other tissues of the body such as skin. Poor collagen structure will cause tooth loss and loss of skin tone. Often found along with other deficiency diseases.

Are vitamins a singular unit?

yes

Can dietary excesses be harmful

yes

Vitamin D: Too Much

•A high intake can cause loss of appetite, nausea, vomiting, constipation •Overuse of supplements may lead to hypervitaminosis D in •Hypercalcemia may also result •Damaging calcium deposited in kidneys, lungs, blood vessels, heart •Too-high levels are extremely rarely caused by food intake or overexposure to the sun

Daily Needs of Vitamin E

•Adults need 15 mg of alpha-tocopherol equivalents •Upper limit is 1,000 mg/day •Current suspicion that the upper limit may be too high

Bioavailability of vitamins varies depending on

•Amount in food •Preparation •Efficiency of digestion and absorption of food •Individual nutritional status •Natural or synthetic

Vitamin E (Alpha-Tocopherol)

•Antioxidant - protects membranes from destruction •Anticoagulant •Cognition, Brain Health? •Vegetable oils and fats, butter, whole grains, leafy greens, nuts, seeds, eggs •Supplements generally not recommended •Deficiency & Toxicity are Rare

Niacin DRI

•Athletes 14-20 mg/day •Males 16 mg/day •Females 14 mg/day Toxicity can occur •UL is 35 mg/day

Functions of Water Soluble Vitamins

•Brain - B1 B6 B12 •Adipose - Niacin, inhibit fat release •Red Blood Cell - B12 B6 Folate •Inhibit Free Radicals - C •Convert Carbs to Pyruvate - B6 Niacin •Convert Pyruvate to Acetyl-CoA - B1 (Thiamin) •Aerobic Metabolism - B2 (Riboflavin) B6 Niacin

Vitamins participate in the

•Building and maintenance of body tissues •Conversion of toxins into waste products •Antioxidant roles

Vitamin D (Cholecalciferol)

•Calcium absorption (D3) •Fortified milk & margarine, butter, fish, eggs, mushrooms •Sun exposure (10-15 min face and hands daily)

Vitamin A (beta-carotene): Too Much

•Carotenoids in foods are not toxic •Overconusming beta-carotene supplements may increase lung cancer risk •Excess carotenoids can cause carotenodermia, orange-yellow pigment is stored in cells •this is not a harmful condition and will correct over time

Vitamin A: Too Little

•Chronic vitamin A deficiency cause eye health problems such as night blindness •Prolonged vitamin A deficiency leads to xerophthalmia -Leading cause of preventable blindness in children, mostly in developing countries •Deficiency can lead to keratinization of epithelial tissues -Cells are unable to function properly, promoting infection

Pantothenic acid

•Conversion of carbohydrate and fat to energy •Synthesis of acetylcholine •Whole foods; meats, grains, vegetables and milk

Vitamin B2 (Riboflavin)

•Energy metabolism, FAD •Protein metabolism •Eye and skin • •Dairy products, whole and enriched grains, meats, fish and eggs, dark greens •Athletes 1.1 mg per 1000 kcals •Males 1.3 mg/day, Female 1.1 mg/day •Deficiency brings fatigue, inflamed tonged, cracked corners of the mouth

Vitamin A: Too Much

•Excessive amounts of preformed vitamin A can accumulate to toxic levels •Toxic levels are generally a result of overconsumption of vitamin A in supplements •Hypervitaminosis A can cause serious liver damage and culminate in death •During pregnancy women should not use any type of vitamin A as it can lead to birth defects in the face, skull, and central nervous system of the child •Can potentially result in osteoporosis and bone fractures in adults

•Water-soluble vitamins can be destroyed by

•Exposure to air •Exposure to ultraviolet light •Water can remove vitamins from foods during cooking and storage •Changes in pH •Heat Food preparation techniques

Biotin

•Helps make fats, protein and glycogen •Gene expression •Grains, beans, meat, cooked eggs, vegetables

Vitamin K

•Helps with blood clotting (prothrombin - important protein coagulant) •Aids in bone metabolism, with vitamin D and calcium absorption Needs •Males 120 mcg/day; Female 90 mcg/day •Athletes - 700 to 900 mcg/day for Sources: •Phylloquinone: Leafy greens, vegetable oils, some fruits and meats. Menaquinone: Bacterial production in gut.

B-Complex Vitamins

•Key role in energy metabolism •Thiamin, riboflavin, niacin, pantothenic acid, and biotin release energy from macronutrients. •B6 and B12, help form amino acids •B12, breakdown of stored carbohydrates •Function as coenzymes and cofactors

Vitamin A (Retinol & Beta-Carotene) (beta-carotene is precursor of vitamin A)

•Maintenance of mucous membranes, skin health and acne treatment, bone health, and helps prevent some forms of blindness •Antioxidant (beta-carotene) •Vitamin A:Animal products, dairy products, egg yolks, •Bata- carotene: fortified cereals, pumpkin, sweet potatoes, carrots spinach, parsley, beef liver

Thiamin (B1): major functions

•Major functions -Carbohydrate metabolism -Branch-chain amino acid metabolism -Synthesis of DNA and RNA -Transmission of nerve impulses - •Toxicity None known

Vitamin B6 or Pyridoxine DRI

•Men 1.3-1.7 mg/day •Women 1.3-1.5 mg/day •Athletes 1.5-2.0 mg/day

Daily Needs of Vitamin A

•Men: 900 micrograms (µg) retinol activity equivalents (RAE) •Women: 700 µg RAE •Upper limit for adults: 3,000 µg •3-6 milligrams of beta-carotene should be consumed every day •This also provides about 50% of the vitamin A intake •Vegetarians need to be particularly conscious about meeting vitamin A intake through carotenoids and beta-carotene-rich foods

Thiamin (B1) Deficiency

•People with calorie restriction will develop deficiency. -eating disorders, starvation, severe alcoholism •Beriberi -Symptoms include loss of appetite, weight loss, confusion, muscle weakness, peripheral neuropathy -Classifications •Wet - edema and congestive heart failure •Dry - muscle wasting without edema or nerve degeneration •Wernicke-Korsakoff syndrome -Advanced form of thiamin deficiency -Caused by chronic alcohol abuse -Progressively damaging brain disorder

Folic Acid (Folate)

•Protein formation (RNA and DNA) •Also helps vitamin B12 do its job; Prevents megaloblastic anemia •Folate is essential for healthy neural tube formation and can prevent Spina Bifida Sources: •Fortified and enriched grains, dark leafy greens, beans & legumes, seeds, liver

Vitamin D: Too Little

•Rickets: vitamin D deficiency disease in children •Bones aren't adequately mineralized with calcium and phosphorus causing them to weaken, leading to bowed legs •Osteomalacia: adult equivalent of rickets •Osteoporosis •Muscle weakness and pain

•Provitamins

•Substances found in foods that are not in a form directly usable by the body •Converted to the active form once absorbed example: Beta-carotene is the provitamin form of vitamin A

Daily Needs of Vitamin D

•Sun exposure cannot meet everyone's vitamin D needs. •Skin pigment melanin and use of sunscreens reduce vitamin D production. •Sunlight intensity during winter in some locations not sufficient to make enough vitamin D •Vitamin D needs based on dietary sources •Adults: At least 600-800 IU/ day •depending on age < 70 •Children: At least 400-600 IU per day •UL: 4,000 IU •but prescription dose can be much higher i.e. 40,000 IU one a week

Vitamin B6 Deficiency

•Symptoms include -Muscle weakness, convulsions, twitching -Inflammation of the skin -Depression, confusion, irritability -Microcytic hypochromic anemia •Fatigue, paleness of skin, shortness of breath, dizziness, lack of appetite •Often caused by excessive alcohol consumption, or restricted caloric intake

Functions of Vitamin D

•The active form acts as a hormone •Regulates two important bone minerals: •calcium (Ca) and phosphorus (P) •Stimulates intestinal absorption of Ca and P to maintain healthy blood levels and build and maintain bones •When dietary calcium is inadequate, Vitamin D and parathyroid hormone cause calcium to leave bones to maintain necessary blood levels. •May help prevent some cancers and type 2 diabetes by reducing chronic inflammation •Potentially helps reduce risk of some autoimmune disorders •Takes part in regulation of blood pressure •Improves anti-inflammatory actions

What are the water soluble vitamins?

•Thiamin (B1) •Riboflavin (B2) •Niacin (B3) •Pyridoxal (B6) •Folate, Folic Acid •Vitamin B12 •Biotin •Pantothenic acid •Ascorbic acid (C) •Choline important co-enzyme

Vitamin K: Too Much or Too Little

•Too much: •No known problems of consuming too much from foods or supplements •People taking anticoagulant medications such as Coumadin (warfarin) need to keep vitamin K intake consistent •Changes in intake can increase or decrease drug effectiveness •Eating too much kale or other dark green leafy vegetables my be problematic •Too little: •Deficiency severe enough to affect blood clotting is extremely rare •Infants are born with too little vitamin K

Vitamin E: Too Much or Too Little

•Too much: •No known risk of consuming too much vitamin E from natural food sources •Overconsumption of synthetic form in dietary supplements and fortified foods can increase risk of a hemorrhage •Too little: •Although rare, chronic deficiency of vitamin E can cause nerve problems, muscle weakness, and free radical damage to cell membranes

Vitamin B6 Toxicity

•Toxicity will occur -Because it is able to be stored in the body -Overdose usually due to excess intake of supplements. -Symptoms include: •Nerve damage •Difficulty walking •Sore tongue •Dermatitis •Depression •Confusion •Irritability •Headaches

Too Much or Too Little B12

•Toxicity: no known risks •Deficiency: -Macrocytic anemia -Pernicious anemia •Fatigue •Shortness of breath •Long-term consequence -Nerve damage (tingling and numbness in arms and legs)

Vitamin storage:

•Vitamin A is mainly stored in the liver •Vitamins K and E are partially stored in the liver •Vitamin D is mainly stored in the fat and muscle tissue •Can build up in body to point of toxicity

•Preformed vitamins

•Vitamins found in foods in their active form

All vitamins contain what atoms

•carbon, hydrogen, and oxygen •Some vitamins contain nitrogen and sulfur

Fat-Soluble Vitamins are stored

•in body fat, the liver, and other areas •Stored for longer times than water-soluble vitamins, so deficiencies take longer to develop than with water-soluble vitamin deficiencies

•Vitamin toxicity, Rare: results from

•ingesting excess vitamins which can lead to tissue saturation •Can damage cells •Generally caused by supplementation and/or too much fortified foods

Chronic vitamin deficiency is likely to cause

•physical symptoms •Symptoms will disappear once the vitamin level in the body is restored •Deficiency can cause permanent damage if deficiency is prolonged