The Vitamins

David L. Gee, PhDProfessor of Food Science and Nutrition

Central Washington UniversityFCSN 245 - Basic Nutrition

Dietary Supplement Use (USA)

$ 4,300,000,000 for vit/min in 1995$ 1,400,000,000 for herbs35-40% adults regular users

females > males 66% multi-vit/min 37% vitamin C 19% vitamin E Calcium supplements

Dietary Supplement Use: Pros

Supplements dietary deficiencies calcium folic acid

Amounts used in some studies not attainable with dietary sources antioxidants

Relatively low cost

Dietary Supplement Use: ConsFalse sense of security

folic acid and pregnancyDoes not contain all potentially useful chemicals in

foods Example: compounds found in plants that may be health

promoting (phytochemicals)Toxicity almost only due to supplement useCosts significant

low income Heavy users of supplements (athletes) Certain supplements are expensive

Chondroitin sulfate – bone/cartilage: $30-50/moSAMe – depression: $40-50/mo

Exam 3 – Tuesday, March 6

Proteins and Amino Acids (chap 6) EAA, RDA, functions, athletes Genetically modified foods (p 472-480) Vegetarian diets Protein quality Protein deficiency (kwashiorkor/marasmus)

Energy and Weight Loss (chap 9) Energy, TEE, BMR, factors affecting BMR, activity, TEF Calorimeters (bomb, direct, indirect) Weight loss, obesity risks, QOL, prevalence, high risk groups Healthy weight, assessment

Calculate BMI, know cutpoints for blood pressure, sugar, lipids Dietary approaches (Balanced, Lo-Carb, restrained CHO, non-diet Exercise Drugs/Surgery

Vitamin & Mineral Deficiency:A Global Progress Report

UNICEF, 2004

80 developing countries studied Accounts for 80% of world population

1/3rd of world population do not reach their physical and intellectual potential because of vitamin/mineral deficiency

Vitamin & Mineral Deficiency:A Global Progress Report

UNICEF, 2004

Vitamin A deficiency40% of children <5yrs with mild to

severe deficiencyCompromised immune deficiencyblindnessstunted growth

Contributes to 1 million deaths of young children/yr

A Solution: supplementation with beta-carotene, 2x/yr, fortification of foods

Vitamin & Mineral Deficiency:A Global Progress Report

UNICEF, 2004

Iodine deficiencyGoiter: enlarged thyroid gland, lethargy

Cretinism: severe mental and physical retardation in infants of deficient mothersReduces IQ by 10-15 points80% of developing countries have goiter rates

of > 10% A Solution: iodized salt (use declined from

75% to 65% in last decade!)

Myxedematous endemic cretinism in the Democratic Republic of Congo : Four inhabitants aged 15-20 years : a normal male and three females with severe longstanding hypothyroidism with dwarfism, retarded sexual development, puffy features, dry skin and hair and severe mental retardation.

Woman with iodine deficiency resulting In a goiter.

Vitamin & Mineral Deficiency:A Global Progress Report

UNICEF, 2004

Iron deficiencyAnemia: fatigue, apathy in adults, poor

academic performance in children (7-10pt drop in IQ) ~45% of children between 6mo-2 yrs

20 countries over 70% A solution

Supplementation (bad taste, constipation)Fortification

• Salt with iodine and iron• Vitamin/mineral mixes added to foods• Fortified foods

The Discovery of Vitamins

The Germ Theory of Disease Scurvy: Disease

of sailors Beri-Beri:

Disease of poor Asians

The Discovery of Vitamins

The Germ Theory of Disease Rickets: Disease of

poor Northern European children

Pellagra: Disease of poor corn eating cultures

The Discovery of VitaminsThe Vitamin Theory of Disease

Scurvy: Disease of sailorsVitamin C deficiency

Beri-Beri: Disease of poor AsiansThiamin deficiency

Rickets: Disease of poor Northern European childrenVitamin D deficiency

Pellagra: Disease of poor corn eating culturesNiacin deficiency

Vitamins: Definition

Organic compound found in foodsRequired in small amountsRequired in the diet (dietary

essential)Proven to be required for health,

growth, and reproduction deficiency syndrome identified

Vitamin NomenclatureFat soluble “A” & Water soluble “B”“Vital amines”

vitamines = vitaminsVitamin B “complex”

collection of water soluble vitamins that function as enzyme co-factors

Vitamin CVitamins D and EMistaken Vitamins

Fat and Water Soluble Vitamins

Fat Soluble Vitamins (A, D, E, K)

Soluble in lipids and solventsExcess stored and not excretedExcess may be toxicDeficiency slow to develop

Fat and Water Soluble Vitamins

Water Soluble VitaminsB vitamins, CSoluble in waterexcess excreted in urine, little

storedgenerally less toxicdeficiency develops quickly

General Functions of Vitamins

Hormones Vitamin D

calcium homeostasis Vitamin A

cell division and development

General Functions of Vitamins

Non-specific chemical reactions

Vitamin E antioxidant

Vitamin C chemical reducing agent

General Functions of Vitamins

Coenzymes or Cofactors chemicals that assist enzymes to function as catalystsB vitamins Vitamin C, A, K

Vitamin A: types and sources

Retinoids retinol, retinal, retinoic acid animal foods, milk fortification

Carotenoids beta-carotene plants vitamin A precurser

Vitamin A: functions

Visual pigment: rhodopsin “night blindness”

Maintenance of epithelial cells regulation of keratin protein synthesis Xeropthlamia intestinal malabsorption

Bone and Immune System Development

Vitamin A: Deficiency

Common in developing countries 3 million children with severe

deficiencyblindness, poor growth and appetite

275 million children with mild deficiencyimpaired immunity

Vitamin A: Toxicity

10 times RDA chronically100 times RDA acute dosehair loss, joint pain, birth defectscarotenoids are non-toxictoxicity due to vitamin

supplement overdose

Vitamin D: Types and Sources

Dietary sources: animal foods, fortified milk

Human Synthesis of Vitamin DSkin: cholesterol + sunlight

“Sunshine Vitamin” – UV-B rays Vitamin D3

5-10 minutes, arms and legs, mid-day sun

Liver & Kidney for activation 1,25-di-OH-D3

Final Exam – Winter 2007

Tuesday, March 15, noon25% vitamins and minerals

Lecture materials General info on vitamins/mineralsDeveloping world vitamin/mineral deficiencies

Required readingChapter 7 (vitamin C ; vitamin A/carotenoids )Chapter 8 (nutrients involved in bone health)Chapter (iron ; folate & B-12 )

Final Exam – Winter 2006

75% comprehensive “questions that you should know

the answers to one or two years from now.”Study class notesReview old exams

Vitamin D: Functions

Helps regulate blood calcium levels When blood calcium levels are low,

vitamin D (and other hormones):Increases dietary calcium absorptionDecreases urinary calcium excretionIncreases bone calcium mobilization

Vitamin D: Deficiency

Rickets bone deformities in children

Osteomalacia weak bones due to low

calcium content Vitamin D deficiency Calcium deficiency multiple pregnancies

Vitamin D: Toxicity

5 times the RDA chronically calcification of soft tissue toxicity due to excessive vitamin supplementation

Calcium

FunctionsBone Structure (99%)Regulator of Metabolism (1%)

nerve impulse transmission muscle contraction blood clotting etc.

Calcium

Regulation of Blood Calcium 10 mg/dl of blood

hypocalcemia & hypercalcemia abnormal muscle cramping nerve irritation

Controlled by: vitamin D, parathyroid hormone, calcitonin

Calcium RDA

1998 RDA’s (AI) 1300 mg/d : children & teens 1000 mg/d : adults 1200 mg/d : older Americans

Usual intakes are low

Osteoporosis

Brittle, weak bones due to loss of total bone mass (minerals and protein)

Prevalence 11% of > 65 yrs 22% of > 65 yrs in 20 yrs 24 million fractures/yr 200,000 hip fractures, 1/6 fatal

3D Visualization of data obtained by x-ray microtomography of the bone structure of the vertebrae of a 50 year old (left) and a 70 year old (right)

This graph shows rates in the USA in 1984-87, adapted from Jacobsen, SJ in American J Public Health 80:872, 1990.

An illustration of the consequence of osteoporosis on the spinal column.

Elderly woman with dowagers hump, a marked abnormal curving of the spine caused by osteoporosis

Other osteoporosis fact:National Osteoporosis Foundation - 2003

10 million with osteoporosis 18 million with low bone density

1 in 2 women will develop osteoporosis sometime in their life (1 in 8 men)

Osteoporosis

Risk FactorsGenetics

Family History Ethnicity Caucasian > Asian > Blacks

Osteoporosis

Risk FactorsGender

associated with declines in estrogen production

post-menopause anorexia, female athletes

Undertreatment of Osteoporosis in Men with Hip Fracture.

Arch. Int. Med. (Oct. 2002)

10 million Americans with osteoporosis 2 million are men

Of 110 men hospitalized with hip fracture 4.5% received treatment for osteoporosis 1 year mortality was 32% Average age 80 yrs

Of 253 women hospitalized with hip fracture 27% received treatment for osteoporosis 1 year mortality was 17% Average age 81 yrs

Osteoporosis

Risk FactorsChronic Calcium Deficiency

Lack of Exercise

Prevention of Osteoporosis

ExerciseDietary Calcium“Rule of 300”

300 mg/d from plant sources 300 mg/d from each serving of dairy

Prevention of Osteoporosis

Other factors that may increase calcium loss high caffeine intake high protein intake high alcohol intake cigarette smoking

Prevention of Osteoporosis

Calcium SupplementsCalcium carbonate

least expensive Tums poor absorption

Calcium citrate/malate (CCM) expensive, well absorbed

Prevention of Osteoporosis

Adequate amounts of vitamin D avoid excesses

Hormonal replacement in high risk women

http://www.mhhe.com/biosci/ap/mediacentral/nutrition_animations/osteoporosis_final.swf

Folic Acid

DRI (RDA): 1998 400 ug/d (180-200 old RDA) 600 ug/d pregnancy (400)

Typical folate intake: 200 ug/dDietary Sources

foliage: fruits & vegetables

Folic Acid

Functions“single carbon metabolism” DNA synthesis (cell division) other reactions

Folic Acid

DeficiencyMegaloblastic Anemia

large abnormal red blood cellsElevated blood homocysteine

CHD risk factor

Folic Acid

DeficiencyNeural Tube Defects

spina bifida - lower body paralysis

required early in pregnancyGrain fortification (1998)

will add 100-200 ug/d to diet

Vitamin B-12

Cobalamine contains cobaltDRI (1998) : 2.4 ug/d (old 2 ug/d)Dietary sources:

animal foods fortified cereals

Vitamin B-12

Functions“single carbon isomerization” synthesis of DNA (folate interaction)

nerve fiber sheath synthesis

Vitamin B-12

DeficiencyPernicious Anemia

megaloblastic anemia nerve injury peripheral weakness and numbness progressive degeneration to death concern among the elderly

Vitamin B-12

Digestion and AbsorptionRequires functioning stomach “intrinsic factor protein” acid production

B-12 and Folic Acid

Excessive folic acid can mask nerve degeneration of pernicious anemia

FDA regulates dosage of folate supplements

FDA limited amount of folate fortification in grains

Nutritional Antioxidants

Oxidative Tissue InjuryOxygen free radicals

unpaired electrons superoxide O2

-.

hydroxy free radical OH.

hydrogen peroxide

Oxidative Tissue Injury

Causes chain reactive damage to:

Cell membranes (hi PUFA)ProteinsDNA

Oxidative Tissue Injury

Associated with:Coronary Heart Disease

oxidized LDL-cholesterolCarcinogenesisChemical ToxicityAuto-immune dieseasesAging

Sources of Oxygen Free Radicals

Normal energy metabolismnutrient + O2 --> CO2 + H2O + energyElectron transport system

O2 --> H2O + energy

but: O2 --> O2-. --> H2O + energy

Sources of Oxygen Free Radicals

D-amino acid metabolism D-AA --> C-skeleton + ammonia +

H2O2

Metabolism of foreign chemicals drugs, pesticides, toxins, etc...

Ozone, nitrogen oxides, UV light, smoke, radiation, etc...

Cellular Antioxidants

Antioxidant EnzymesCatalase (iron)

removes hydrogen peroxidesSuperoxide Dismutase (Cu,

Zn) removes superoxide radicals

Cellular Antioxidants

Antioxidant EnzymesGlutathione Peroxidase (Se)

removes peroxidesMineral supplements are ineffective and may be toxic

Cellular Antioxidants

Nutritional AntioxidantsVitamin E Carotenoids and other plant phytochemicals

Vitamin C

Vitamin E

TocopherolsDietary sources:

widespread, highest in plant oilsDeficiency:

rare in adults premature infants: hemolytic

anemia

Vitamin E

Function: free radical scavenger in membranes

RDA: 8-10 mg/d“Research dosages”: 400-800 mg/dToxicity: rare, may be non-toxic

below 1000 mg/d

Plant Phytochemicals

Beta-carotene & carotenoidsPlant polyphenols

garlic green tea grape skins cruciferous vegetables

Antioxidants with “specific niches”

Vitamin C

Ascorbic AcidFood Sources

fruits vegetables

Deficiency: Scurvy poor wound healing impaired immune system

Vitamin C Functions

Antioxidant water soluble free radical scavenger

Collagen synthesis connective tissue protein

Synthesis of neurotransmitters, thyroxine, etc.

Aids in absorption of dietary iron

Vitamin C

RDA : 60 mg/dRDA (smokers): 100 mg/dtypical intake 100 mg/d“Effective research dosages” : 100-500 mg/d

Vitamin C

“Toxicity” > 1000 mg/ddiarrheakidney stonespromotes “iron overload” toxicityInterfers with important lab tests

blood in stools (colon cancer) urinary and blood glucose (diabetes)

Iron

Functions:HemoglobinMyoglobinIron enzymes

catalase electron transport system

Iron Deficiency

Iron deficiency anemia fewer, smaller, paler red blood cells fatigue

5-10% of US premenopausal women

up to 40% of population in developing countries

Iron Deficiency CausesBlood loss

menstrual blood loss parasites and bleeding ulcerations

Inadequate dietary intakeRDA men = 10 mg/dRDA women = 15 mg/dUS usual intake 6 mg/1000 Cal

Dietary Sources of IronHeme Iron

meats (Hb & Mb) 20-30% absorbed

Non-heme Iron plants inorganic iron 1-10% absorbed vitamin C increases absorption iron cookware

Iron Overload Toxicity

Children (accidental poisoning) Men and post-menopausal

womenGenetic “defect”

improved iron absorptionExcess iron is a pro-oxidant.

oxidized LDL-C tissue injury

Iron Overload Toxicity

May occur in 10% of menTreatment

avoid iron containing supplements

avoid excess vitamin C supplements

bleeding or blood donation