Transcript The Vitamins - Central Washington University

Summer 2005 – Final Exam
 Thursday, July 28, 12:50PM, 201 PE
 Gee
Lecture materials
Chapter 11-Achieving and Maintaining a Healthful Body Weight
Chapter 9 – Nutrients Involved in Bone Health
20 MC/TF questions
See www.cwu.edu/~geed tomorrow for study guide
Take Home essay question (turn in with final)
What is the role of American Society in Addressing the US Obesity
Crisis?
1 page, double space, 12 pt font, 1” margins
10 pts: grammatically perfect, well thought out, clearly states and
defends position.
 Bergman/Bennett – 40 MC/TF questions
The Vitamins
David L. Gee, PhD
Professor of Food Science and Nutrition
Central Washington University
FCSN 245 - Basic Nutrition
Dietary Supplement Use
(USA)
$ 4,300,000,000 for vit/min in 1995
$ 1,400,000,000 for herbs
35-40% 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
Useful for those with limited caloric intake
Elderly
Dieters
children
Amounts used in some studies not attainable
with dietary sources
antioxidants
Relatively low cost
Dietary Supplement Use:
Cons
False sense of security
folic acid and pregnancy
Supplement may a marker chemical and not the actual
protective agent
Does 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 use
Costs significant
low income
Heavy users of supplements (athletes)
Certain supplements are expensive
Chondroitin sulfate – bone/cartilage: $30-50/mo
SAMe – depression: $40-50/mo
The Discovery of
Vitamins
The Germ Theory of Disease
Scurvy: Disease of sailors
Beri-Beri: Disease of poor Asians
Rickets: Disease of poor Northern
European children
Pellagra: Disease of poor corn eating
cultures
The Discovery of
Vitamins
The Vitamin Theory of Disease
Scurvy: Disease of sailors
Vitamin C deficiency
Beri-Beri: Disease of poor Asians
Thiamin deficiency
Rickets: Disease of poor Northern European
children
Vitamin D deficiency
Pellagra: Disease of poor corn eating cultures
Niacin deficiency
Vitamin
Nomenclature
Fat soluble “A” & Water soluble “B”
“Vital amines” = vitamines =
vitamins
Vitamin B “complex”
collection of water soluble vitamins that function as
enzyme co-factors
Vitamin C
Vitamins D and E
Mistaken Vitamins
Vitamins: Definition
Organic compound found in foods
Required in small amounts
Required in the diet (essential)
Proven to be required for health,
growth, and reproduction
deficiency syndrome identified
Fat and Water Soluble
Vitamins
Fat Soluble Vitamins (A, D, E, K)
Soluble in lipids and solvents
Excess stored and not excreted
Excess may be toxic
Deficiency slow to develop
Fat and Water Soluble
Vitamins
Water Soluble Vitamins
B vitamins, C
Soluble in water
excess excreted in urine, little
stored
generally less toxic
deficiency 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 catalysts
B vitamins
Vitamin C, A, K
Vitamin D: Types and
Sources
Dietary sources: animal foods,
fortified milk
Human Synthesis of Vitamin D
Skin: 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
Vitamin D: Functions
Helps regulate blood
calcium levels
Dietary calcium absorption
Urinary calcium excretion
Bone calcium metabolism
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
Functions
Bone 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
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
Osteoporotic Bone
Normal Bone
Changes in the spine with
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 Factors
Genetics
Family History
Ethnicity
Caucasian > Asian > Blacks
Osteoporosis
Risk Factors
Gender
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 Factors
Chronic Calcium Deficiency
Lack of Exercise
Prevention of
Osteoporosis
Exercise
Dietary 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 Supplements
Calcium 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
If you have a family history of
osteoporosis:
Get a bone scan
Folic Acid
DRI (RDA): 1998
400 ug/d (180-200 old RDA)
600 ug/d pregnancy (400)
Typical folate intake: 200 ug/d
Dietary Sources
foliage: fruits & vegetables
Folic Acid
Functions
“single carbon metabolism”
DNA synthesis (cell division)
other reactions
Folic Acid
Deficiency
Megaloblastic Anemia
large abnormal red blood cells
Elevated blood homocysteine
CHD risk factor
Folic Acid
Deficiency
Neural Tube Defects
spina bifida - lower body
paralysis
required early in pregnancy
Grain fortification (1998)
will add 100-200 ug/d to diet
Iron
Functions:
Hemoglobin
Myoglobin
Iron 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
Causes
Blood loss
menstrual blood loss
parasites and bleeding ulcerations
Inadequate dietary intake
RDA men = 10 mg/d
RDA women = 15 mg/d
US usual intake 6 mg/1000 Cal
Dietary Sources of
Iron
Heme 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 women
Genetic “defect”
improved iron absorption
Excess iron is a pro-oxidant.
oxidized LDL-C
tissue injury
Iron Overload
Toxicity
May occur in 10% of men
Treatment
avoid iron containing
supplements
avoid excess vitamin C
supplements
bleeding or blood donation
Final Advice from Your
Nutrition Professor:
Eat your vegetables!
And fruits and whole grains too!
Watch your weight!
Easier to maintain your weight than to lose
weight you’ve gained
Everything in moderation!
You can have your cake and eat it too!
Enjoy your food and your good health!