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Water-Soluble Vitamins. Water soluble Readily excreted – expensive urine Can be lost from food by cooking/storage Typically work as part of enzymes in metabolism Relatively high absorption rate Severe deficiencies rare Vitamins – Niacin, Thiamine, Folic Acid, Riboflavin, B12, and C.

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Water soluble vitamins l.jpg
Water-Soluble Vitamins

  • Water soluble

  • Readily excreted – expensive urine

  • Can be lost from food by cooking/storage

  • Typically work as part of enzymes in metabolism

  • Relatively high absorption rate

  • Severe deficiencies rare

  • Vitamins – Niacin, Thiamine, Folic Acid, Riboflavin, B12, and C.


Enrichment act of 1941 and 1998 l.jpg
Enrichment Act of 1941 and 1998

  • Milling of rice, wheat, oats, etc…

  • significantly reduces nutritional quality

  • Whole grains contain original nutrients

  • Enrich with

  • thiamin, riboflavin, niacin, folate, iron

  • Enriched grains still

  • deficient in B-6, magnesium and zinc


Thiamin l.jpg
Thiamin

  • Destroyed by alkaline and heat

  • Coenzyme: Thiamin pyrophosphate (TPP)

  • Absorbed in the jejunum by a carrier-mediated system

  • Transported by RBC in the blood

  • Deficiency

  • Beriberi

    • Weakness, nerve degeneration, irritability, poor arm/leg coordination, loss of nerve transmission

    • Edema, enlarge heart, heart failure


Food sources of thiamin l.jpg
Food Sources of Thiamin

  • Wide variety of food

  • White bread, pork, hot dogs, luncheon meat, cold cereal

  • Enriched grains/ whole grains

  • Thiaminase found in raw fish

  • 1.1 mg/day for women

  • 1.2 mg/day for men

  • Most exceed RDA in diet

  • Surplus is rapidly lost in urine; non toxic


Riboflavin l.jpg
Riboflavin

  • Coenzymes:

    • Flavin mononucleotide (FMN)

    • Flavin adenine dinucleotide (FAD)

  • Oxidation-reduction reactions

  • Electron transport chain

  • Citric Acid Cycle

  • Catabolism of fatty acids


Absorption transport metabolism of riboflavin l.jpg
Absorption, Transport, & Metabolism of Riboflavin

  • HCL in the stomach release riboflavin from its bound forms

  • Absorption

    • Active or facilitated transport during low to moderate intake

    • Passive absorption during high intake

    • Increase with intake

  • Transported by a protein carrier in the blood


Functions of riboflavin l.jpg
Functions of Riboflavin

  • Accepts electrons

  • Electron Transport Chain

  • FAD FADH2

  • Succinate Fumarate

  • Citric Acid Cycle

  • Participates in beta oxidation

  • FMN shuttles hydrogen ions and electrons to into the electron transport chain

  • Metabolism of oxidized glutathione


Deficiency of riboflavin l.jpg
Deficiency of Riboflavin

  • Ariboflavinosis

    • Glossitis, cheilosis, seborrheic dermatitis, stomatitis, eye disorder, throat disorder, nervous system disorder

  • Occurs within 2 months

  • Usually in combination with other deficiencies


Glossitis fig 10 4 l.jpg

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Glossitis (Fig. 10-4)


Who is at risk for deficiency l.jpg
Who is at Risk For Deficiency? required for reproduction or display.

  • Rare

  • Low milk/dairy intake

  • Alcoholics

  • Long term phenobarbital use


Food sources of riboflavin l.jpg
Food Sources of Riboflavin required for reproduction or display.

  • Milk/products

  • Enriched grains

  • Liver

  • Oyster

  • Brewer’s yeast

  • Sensitive to uv radiation (sunlight)

  • Stored in paper, opaque plastic containers


Rda for riboflavin l.jpg
RDA for Riboflavin required for reproduction or display.

  • 1.1 mg/day for women

  • 1.3 mg/day for men

  • Average intake is above RDA

  • Toxicity not documented


Niacin l.jpg
Niacin required for reproduction or display.

  • Nicotinic acid (niacin) & nicotinamide (niacinamide)

  • Coenzyme

    • Nicotinamide adenine dinucleotide (NAD)

    • Nicotinamide adenine dinucleotide phosphate (NADP)

  • Oxidation-reduction reaction

  • Metabolic reactions


Absorption transport and storage of niacin l.jpg
Absorption, Transport and Storage of Niacin required for reproduction or display.

  • Readily absorbed from the stomach and small intestine

  • Absorption: active transport and passive diffusion

  • Transported from the liver to all of the tissues where it is converted to the coenzymes


Deficiency of niacin l.jpg
Deficiency of Niacin required for reproduction or display.

  • Pellagra

    • 3 Ds

    • Occurs in 50-60 days

    • Decrease appetite & weight

  • Prevented with an adequate protein diet

  • Enrichment Act of 1941

  • Only dietary deficiency disease to reach epidemic proportions in the U.S.

  • Who is at risk?

    • (Untreated) corn as main staple, poor diet, Hartnup disease, alcoholics


Dermatitis of pellegra fig 10 5 l.jpg

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Dermatitis of Pellegra (Fig. 10-5)


Food sources of niacin l.jpg

Mushroom required for reproduction or display.

Enriched grains

Beef, chicken, turkey, fish

Heat stable; little cooking loss

60mg tryptophan can be converted into 1 mg niacin

Food Sources of Niacin


Rda for niacin l.jpg
RDA for Niacin required for reproduction or display.

  • 14 NE/day for women

  • 16 NE/day for men


Niacin as a medicine l.jpg
Niacin as a Medicine required for reproduction or display.

  • 75-100 x RDA can lower LDL and TG and increase HDL

  • Slow/ reverse progression of atheroscelerosis with diet and exercise

  • Toxicity effects

    • Flushing of skin, itching, nausea, liver damage


Biotin l.jpg
Biotin required for reproduction or display.

  • Free and bound form

  • Biocytin (protein bound form)

  • Biotinidase in small intestine

  • Metabolism of CHO, fat, protein (C skeleton)

  • DNA synthesis


Functions of biotin l.jpg
Functions of Biotin required for reproduction or display.

  • Assists in the addition of CO2 to substances

  • Carboxylation of acetyl-CoA to form malonyl-CoA for the elongation of a fatty acid chain

  • Addition of CO2 to pyruvate to yield oxaloacetate

  • Breaks down leucine

  • Allows 3 essential amino acids to be oxidized for energy


Food sources of biotin l.jpg
Food Sources of Biotin required for reproduction or display.

  • Cauliflower, yolk, liver, peanuts, cheese

  • Intestinal synthesis of biotin

  • Biotin content only available for a small number of foods

  • Unsure as to bioavailablity of synthesized biotin

  • We excrete more than we consume

  • Avidin inhibits absorption

    • > a dozen of raw eggs a day to cause this effect


Biotin needs l.jpg
Biotin Needs required for reproduction or display.

  • Adequate Intake is 30 ug/day for adults

  • This may overestimate the amount needed for adults

  • No Upper Limit for biotin


Who is at risk for deficiency25 l.jpg
Who is at Risk For Deficiency? required for reproduction or display.

  • Rare

  • High intake of raw egg white diet

  • Alcoholics

  • Biotinidase deficiency

  • Anticonvulsant drug use

  • Signs & symptoms: skin rash, hair loss, convulsion, neurological disorders, impaired growth in children


Vitamin b 6 pyridoxal pyridoxine pyridoxamine l.jpg
Vitamin B-6: Pyridoxal, Pyridoxine, Pyridoxamine required for reproduction or display.

  • Main coenzyme form: pyridoxal phosphate (PLP)

  • Activate enzymes needed for metabolism of CHO, fat , protein

  • Transamination

  • Synthesis of hemoglobin and oxygen binding and white blood cells

  • Synthesis of neurotransmitters


Deficiency of vitamin b 6 l.jpg
Deficiency of Vitamin B-6 required for reproduction or display.

  • Microcytic hypochromic anemia

  • Seborrheic dermatitis

  • Convulsion, depression, confusion

  • Reduce immune response

  • Peripheral nerve damage

  • Who is at risk?

    • Elderly

    • Alcoholics

      • Alcohol decreases absorption

      • Destroy the coenzyme form


Food sources of vitamin b 6 l.jpg
Food Sources of Vitamin B-6 required for reproduction or display.

  • Meat, fish, poultry

  • Whole grains (not enriched back)

  • Banana

  • Spinach

  • Avocado

  • Potato

  • Heat and alkaline sensitive


Rda for vitamin b 6 l.jpg
RDA for Vitamin B-6 required for reproduction or display.

  • 1.3 mg/day for adults

  • 1.7 mg/day for men over 50

  • 1.5 mg/day for women over 50

  • Daily Value set at 2 mg

  • Average intake is more than the RDA


Factors that affect b 6 requirement l.jpg
Factors That Affect B-6 Requirement required for reproduction or display.

  • L-DOPA-medication used to treat Parkinson’s disease and

  • Isoniazid-antituberculosis medication

  • Reduce blood concentration of PLP

  • Need extra vitamin B-6

  • Preeclampsia

  • Reduce blood concentration of PLP

  • Will supplementation will reduce preeclampsia?


B 6 as a medicine l.jpg
B-6 As A Medicine? required for reproduction or display.

  • PMS

    • B-6 to increase the level of serotonin

    • Improve depression

    • Not a reliable treatment

  • Carpal tunnel syndrome

  • Toxicity potential

  • Can lead to irreversible nerve damage with > 200 mg/day


Folate folic acid folacin l.jpg
Folate (Folic acid, Folacin) required for reproduction or display.

  • Consists of pteridine group, para-aminobenzoic acid (PABA), and glutamic acid

  • Coenzyme form: tetrahydorfolic acid (THFA)


Functions of folate l.jpg
Functions of Folate required for reproduction or display.

  • DNA synthesis

    • Transfer of single carbon units

    • Synthesis of adenine and guanine

    • Anticancer drug methotrexate

  • Homocysteine metabolism

  • Neurotransmitter formation


Deficiency of folate l.jpg
Deficiency of Folate required for reproduction or display.

  • Similar signs and symptoms of vitamin B-12 deficiency

  • Pregnant women

  • Alcoholics

    • Interferes with the enterohepatic circulation of bile/folate


Neural tube defects l.jpg

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Neural Tube Defects

  • Spina bifida

  • Anencephaly

  • Importance of folate before and during pregnancy

(Fig. 10-8)


Food sources of folate l.jpg
Food Sources of Folate required for reproduction or display.

  • Liver

  • Fortified breakfast cereals

  • Grains, legumes

  • Foliage vegetables

  • Susceptible to heat, oxidation, ultraviolet light


Rda for folate l.jpg
RDA for Folate required for reproduction or display.

  • 400 ug/day for adults

  • Daily Value is set at 400 ug


Vitamin b 12 l.jpg
Vitamin B-12 required for reproduction or display.

  • Cyanocobalamin. methlcobalamin,

  • 5-deoxyadenosylcobalamin

  • Contains cobalt

  • Folate metabolism

  • Maintenance of the myelin sheaths

  • Rearrange 3-carbon chain fatty acids so can enter the Citric Acid Cycle


Absorption of vitamin b 12 fig 10 10 l.jpg

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Absorption of Vitamin B-12 (Fig. 10-10)


Functions of vitamin b 12 l.jpg
Functions of Vitamin B-12 required for reproduction or display.

  • Helps convert methylmalonyl CoA to succinyl CoA (citric acid cycle)

  • RBC formation

  • Nerve functions

    • Maintains myelin sheath

  • Megalobalstic anemia


Deficiency of vitamin b 12 l.jpg
Deficiency of Vitamin B-12 required for reproduction or display.

  • Pernicious anemia

    • Never degeneration, weakness

    • Tingling/numbness in the extremities (parasthesia)

    • Paralysis and death

    • Looks like folate deficiency

  • Usually due to decreased absorption ability

  • Achlorhydria especially in elderly

  • Injection of B-12 needed

  • Takes ~20 years on a deficient diet to see nerve destruction


Who is at risk for deficiency42 l.jpg
Who is at Risk For Deficiency? required for reproduction or display.

  • Vegans

  • Breastfed infants of vegan moms

  • Elderly

  • Individuals with AIDS or HIV


Food sources of vitamin b 12 l.jpg

Synthesized by bacteria, fungi and algae required for reproduction or display.

(Stored primarily in the liver)

Animal products

Organ meat

Seafood

Eggs

Hot dogs

Milk

Food Sources of Vitamin B-12


Rda for vitamin b 12 l.jpg
RDA for Vitamin B-12 required for reproduction or display.

  • 2.4 ug/ day for adults and elderly adults

  • Average intake exceeds RDA

  • B-12 stored in the liver

  • Non-toxic


Vitamin c l.jpg
Vitamin C required for reproduction or display.

  • Ascorbic acid (reduced form), dehydroascorbic acid (oxidized form)

  • Synthesized by most animals (not by human)

  • Absorbed by a specific energy dependant transport system

  • Passive transport if intake is high

  • Decrease absorption with high intakes

  • Excess excreted


Functions of vitamin c l.jpg
Functions of Vitamin C required for reproduction or display.

  • Reducing agent (antioxidant)

  • Iron absorption

  • Synthesis of carnitine, tryptophan to serotonin, thyroxine, cortiscosteroids, aldosterone, cholesterol to bile acids

  • Immune functions

  • Cancer prevention?

  • Collagen synthesis


Collagen synthesis fig 10 12 l.jpg

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Collagen Synthesis (Fig. 10-12)


Antioxidant l.jpg
Antioxidant required for reproduction or display.

  • Can donate and accept hydrogen atoms readily

  • Water-soluble intracellular and extracellular antioxidant

  • Must be constantly enzymatically regenerated

  • Needs are higher for smokers


Deficiency of vitamin c l.jpg

Scurvy required for reproduction or display.

Deficient for 20-40 days

Fatigue, pinpoint hemorrhages

Bleeding gums and joints. Hemorrhages

Associated with poverty

Rebound scurvy

immediate halt to excess vitamin C supplements

Who is at risk?

Infants, elderly men

Alcoholics, smokers

Deficiency of Vitamin C


Food sources of vitamin c l.jpg

Citrus fruits required for reproduction or display.

Potatoes

Green peppers

Cauliflower

Broccoli

Strawberries

Romaine lettuce

Spinach

Easily lost through cooking

Sensitive to heat

Sensitive to iron, copper, oxygen

Food Sources of Vitamin C


Rda for vitamin c l.jpg
RDA for Vitamin C required for reproduction or display.

  • 90 mg/day for male adults

  • 75 mg/day for female adults

  • +35 mg/day for smokers

  • Average intake ~72 mg/day

  • Fairly nontoxic (at <1 gm)

  • Upper Level is 2 g/day

  • Warning to people with hemochromatosis, oxalate kidney stones


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