http://www.thedailygreen.com/healthy-eating/eatsafe/top-sources-vitamin-E-44111408
http://science.kqed.org/quest/2011/10/14/vitamin-esupplements-increase-prostate-cancer-risk/
VITAMIN E
Corey Crowe, Brittany Shannon,
Amanda Sperry, and Jocelyn Tomsic
Overview:
• Composition
• Food Sources
(plant/animal)
• Functions
• Interactions with other
nutrients/medications
• Digestion & Absorption • Deficiencies
• Transport &
• Toxicity
Metabolism
• Vitamin E and Diseases
• Storage & Excretion
Vitamin E Composition
•
Composed of 8 compounds (vitamers) divided into two
classes:
o
Tocopherols:

o
Tocotrienols:

•
which have saturated side chains with 16 carbons
which have unsaturated side chains with 16 carbons
Each class is composed of 4 vitamers that differ in the #
and location of methyl groups on the chromanol ring.
Vitamin E Composition
http://lipidlibrary.aocs.org/topics/tocopherols/index.htm
● Only the alpha-tocopherol has biological activity
and can meet the body’s requirement for the
vitamin.
Vitamin E Classification
•
•
•
Is part of the fat-soluble vitamin family (A,D,E,K)
Is also an important antioxidant (A,C,E)
Like the other fat-soluble vitamins, vitamin E, is very
susceptible to destruction during food preparation and
storage.
o Tocopherols can become oxidized with long-term
exposure to air.
o Exposure to light and heat can also lead to its increased
destruction.
DIETARY VITAMIN
http://www.fitnessrxwomen.com/nutrition/health
y-eating-tips/improve-health-performance-withvitamin-e/
Food Sources
● Found in various forms
however, is predominantly
found in plant sources,
especially the oils from plants.
● It is recommended getting
proper amounts of vitamin E
from mostly food sources rather
than supplements.
Plant Sources
•
•
•
•
•
•
Vegetable Oil
Nuts
Seeds
Avocados
Spinach
Kale
Animal Sources
http://ljayhealth.wordpress.com/2012/02/23/healthbenefits-of-spinach-2/
•
Concentrated fats of meats
Supplementation Sources
•
•
http://www.ehow.com/how_4542_absorb-vitamin-e.html
•
http://ods.od.nih.gov/factsheets/VITAMINEHealthProfessional/
Vitamin E is present in almost every
multivitamin pill.
Alpha-tocopherol in dietary supplements
and fortified foods is often esterified to
prolong its shelf life while protecting its
antioxidant properties.
People need approximately 50% more IU
of synthetic alpha tocopherol from dietary
supplements and fortified foods to obtain
the same amount of the nutrient when
compared to the natural form.
DIGESTION &
ABSORPTION
http://cnx.org/content/m44742/latest/
Digestion
•
Tocopherols are found free in foods, whereas the
tocotrienols are found esterified and must be
hydrolyzed before absorption.
● Pancreatic esterase and duodenal mucosal esterase
function in the lumen and/or at the brush border
membranes of enterocytes to hydrolyze tocotrienols
and synthetic ester alpha-tocopherols for absorption.
Absorption
•
http://www.smscs.com/picview.php?title=digestive+syst
em+images&photo=http%3A%2F%2Fwww.macroevoluti
on.net%2Fimages%2Fhuman-digestive-system-225401-12.jpg
•
Vitamin E is primarily absorbed
in the jejunum by passive
diffusion.
o Diffused like lipids using bile
salts for emulsification,
solubilization, and micelle
formation
Uptake of vitamin E into cells occurs as
lipoproteins are taken up by body tissues
and can occur in several ways:
1. Through receptor-mediated
uptake of LDLs
2. Through lipoprotein lipasemediated hydrolysis of
chylomicrons and VLDLs
3. Through HDL-mediated
nutrient delivery
TRANSPORT &
METABOLISM
Transport
•
•
In the enterocyte, absorbed tocopherols are incorporated
into chylomicrons for transportation through the lymph
and then into circulation.
During transport in the chylomicrons, tocopherol is
transferred among the other lipoproteins, including HDLs
and LDLs.
o LDLs posses the highest concentrations of vitamin E.
http://www.sigmaaldrich.com/life-science/metabolomics/enzyme-explorer/learningcenter/plasma-blood-protein/lipoprotein-function.html
Metabolism
•
Chylomicron remnants deliver vitamin E to the liver to
be metabolized.
o However only RRR alpha-tocopherol is
incorporated into VLDL for recirculation back into
the blood to be transported to other tissues.
http://www.theheart.org/fr/documents/infoSite/infocus/infocus.html
STORAGE &
EXCRETION
Storage
•
There is no single storage organ for vitamin E.
o The liver, lungs, heart, muscles, adrenal glands,
spleen, and the brain are the major tissues that take
up small amounts of vitamin E.
•
The largest amount (over 90%) occurs in concentrated
unesterified form in fat droplets in adipose tissue.
o The vitamin E in adipose tissue increases linearly
with the intake of it, however the release of it from
adipose tissue is much slower even during times of
low intake.
Excretion
•
•
After the liver has absorbed the alpha-tocopherol form of vitamin E and
absorption in the small intestine has occurred, the liver secretes only
alpha-tocopherol via the hepatic alpha-tocopherol transfer protein.
The liver will metabolize and excrete other forms of vitamin E.
•
•
•
•
Begins with a hydroxylation reaction that requires Cytochrome P450.
Then a series of reactions within Beta -oxidation occurs to shorten
vitamin E’s side chains.
The end product results in a group of carboxyethyl
hydroxychroman
For urinary excretion this carboxyethyl hydroxychroman combines
with sulfate to be eliminated.
http://novenamaternity.com/ingredients/
ANTIOXIDANT
FUNCTION
http://www.wesleyvirgin.com/give-your-body-the-gift-of-kale/
Antioxidant Role
•
•
•
The main function of vitamin E:
o As an antioxidant, it helps to maintain membrane integrity within
cells.
The mechanism by which vitamin E protects the membranes from
destruction is through its ability to prevent oxidation of unsaturated FA
contained in the phospholipids of the membrane.
The lungs, brain, and RBCs are the most vulnerable AND are the most
susceptible to oxidation.
http://face-andemotion.com/dataface/anatomy/braincranium.jsp
http://www.odiadoctors.com/respiratoryfunctions-lungs/
Antioxidant Role
•
•
•
•
As an antioxidant, vitamin E can destroy singlet molecular
oxygen and stop reactions involving free radicals.
Its ability to diminish free radicals is related to the hydroxyl
group on the chromane ring portion of the vitamin.
The hydroxyl group gives up hydrogen and therefore
inactivates the free radical.
Not all tocopherols are equal in their ability to diminish free
radicals.
o Alpha-tocopherol was found to be more effective than betatocopherol, gamma-tocopherol, or sigma-tocopherol.
http://trialx.com/curebyte/2011/07/06/immune-function-photos-and-relatedclinical-trials/
IMMUNE FUNCTION
Immune Response
•
•
Needed to boost the body’s immune system
so that it can fight off invading bacteria and
viruses.
Vitamin E can partially overcome
immunosuppression of substances like:
o High levels of PUFA
o Severe selenium deficiency
•
High levels of vitamin C can protect tissue
levels of vitamin E and may indirectly
contribute to the immunoenhancement by
vitamin E.
http://healthy-proteins.blogspot.com/2012/11/optimize-yourimmune-system-naturally.html
INTERACTIONS WITH
OTHER NUTRIENTS
How Does Vitamin E
Get Along With…?
•
•
•
•
Selenium
Vitamin C
Dietary polyunsaturated FA
Other fat-soluble vitamins
(especially Vitamin K)
Vitamin E and Selenium
•
•
Selenium has roles in reproduction, thyroid hormone
metabolism, DNA synthesis, and protection from oxidative
damage and infection.
The actions of both nutrients complement each other
o Higher concentrations of one can reduce the effects of
lower concentration of the other, creating a
counterbalancing body system.
http://healthfreedoms.org/2009/05/27/selenium-in-dietoverview/
Vitamin E and Vitamin C
https://az.naturesgardendelivered.com/blog/increase-your-vitamin-cintake-and-ward-off-seasonal-allergies/
•
•
http://reebokcrossfit5thave.com/tag/vitamin-c/
Similar to vitamin E’s relationship with Selenium, Vitamin C
also complements vitamin E.
Though vitamin E is an antioxidant, it can become oxidized
when it interacts with a free radical, therefore creating more
oxidative damage.
o But vitamin C can interact with oxidized vitamin E, reducing
free radicals and regenerating the benefits of vitamin E.
Vitamin E and
Polyunsaturated Fatty Acids
•
Vitamin E requirements increase or decrease as the
degree of unsaturated fatty acids in body tissues rise or
fall, respectfully.
o Body tissue lipids are in turn influenced by dietary
lipid intake.
• Foods high in polyunsaturated FA also tend to be
relatively good sources of vitamin E.
http://www.beefitzxt.com/main/products
Vitamin E and
Fat-soluble Vitamins
•
•
•
•
High intake of vitamin E can interfere with
other fat-soluble vitamins.
Vitamin E inhibits beta-carotene absorption
and its metabolism in the intestine.
Impairs vitamin K absorption and its
metabolism.
o The effects of vitamin E may increase the
risk for bleeding secondary to the
interference of vitamin K’s ability to clot
blood
Vitamin E is also important in helping your
body make red blood cells, and it helps the
body to use vitamin K.
http://www.hollandandbarrett.com/pages/categories.asp?cid=70
Possible Interactions with
Medications:
-Antidepressant medications (ex:
Norpramin)
-Chemotherapy drugs (ex:
chlorambucil)
-Antipsychotic medications (ex:
chlorpromazine)
-Anticoagulant and antiplatelet
medications
-AZT (A medication used to treat
HIV and AIDS)
-Chemotherapy and radiotherapy
-Aspirin
-Bile acid sequestrants (ex:
Cholestyramine, cholestipol)
-Orlistat
-Statins (ex: Niacin and Zocor)
-Beta-blockers (ex: Propranolol)
DEFICIENCIES
AND SYMPTOMS
Deficiencies
http://www.123rf.com/photo_7732679_feet-on-a-bathroomscale-with-the-word-help-on-the-screen-isolated--includesclipping-path.html
•
•
•
http://immunetreeblog.com/extreme-fatigue-whatcauses-extreme-tiredness/
Deficiencies of vitamin E are rare in humans, but many people
have slightly low levels.
Since the digestive tract requires fat to absorb vitamin E,
people with fat-malabsorption disorders (for example
steatorrhea or cystic fibrosis) are more likely to become
deficient rather than people without such disorders.
Deficiencies that last a long time could cause liver and kidney
problems.
Symptoms
•
•
•
•
•
•
•
Myopathy (skeletal muscle pain) and Weakness
Ceroid Pigment Accumulation (fat accumulation)
Hemolytic Anemia
Degenerative Neuropathy
Ataxia
Loss of Vibratory Sense
Loss of Coordination of Limbs
http://myweb.tiscali.co.uk/ataxia.pages/
TOXICITY
http://www.newautism.com/heavy-metaltoxicity/158/
Problems Associated
with Toxicity
•
•
•
•
•
Vitamin E appears to be one of the least toxic vitamins.
It is not mutagenic, carcinogenic, or teratogenic
Oral supplementations of vitamin E do not result in serious side
effects
Mild gastrointestinal problems may occur with intake between
200 and 800 mg.
Due to the increased tendency for bleeding, because of
antiplatelet effects and/or abnormal blood clotting, a Tolerable
Upper Intake of 1,000 mg/day of alpha-tocopherol has been
suggested.
Toxicity Symptoms
•
•
•
•
•
•
•
•
•
Gastrointestinal Distress
Nausea
Diarrhea
http://news.softpedia.com/news/Common-AntibioticEffective-Against-Bloating-and-Flatulence-18165.shtml
Flatulence
Impaired Blood Coagulation
Increased Severity of Respiratory Infections
Muscle Weakness
Fatigue
Double Vision
http://medicalmarijuanalabprojectthursdayam
.wikispaces.com/file/detail/nausea.gif/386256
408
VITAMIN E AND
DISEASE
Vitamin E & Heart Disease
•
•
Results have not shown that
vitamin E helps lower the risk
of Heart Disease
One of the largest studies, the
Heart Outcomes Prevention
Evaluation (HOPE) trial, found
that taking 400 IU of vitamin E
(d-alpha-tocopherol) daily did
not lower the number of heart
attacks, strokes, or deaths from
heart disease among men and
women who already had heart
disease or were at high risk for
it.
•
What about in healthy people
who were at low risk for heart
disease?
o Two large trials also found
no protection from vitamin
E. In one -- the Physicians'
Health Study II -- vitamin
E was associated with a
higher risk of stroke
http://health.allrefer.com/pictures-images/vitamin-e-and-heart-disease.html
Vitamin E and Cancer
•
There is no concrete evidence to support the fact that Vitamin E can
cure/prevent cancer
o There is a small amount of evidence suggesting that taking vitamin E along
with vitamin A and vitamin C, or as part of a multivitamin would help
protect people who had colorectal adenomas, a precursor for colon cancer.
o There are several studies showing that intake of multiple vitamin
supplements, including vitamin E can lower prostate cancer.
•
Vitamin E has some positive effects on cancer treatment
o A study of 108 people taking chemotherapy drug cisplatin found that taking
a vitamin E supplement during and as long as three months after treatment
reduced nerve damage from the drug.
o Some doctors worry though that large doses of antioxidants could interfere
with chemotherapy medications.
Vitamin E and Eye
Health
•
http://www.lookupinfo.org/easy_read_information/easy_
read_eye_health_information.aspx
Vitamin E (400 IU) combined with other antioxidants including
zinc, beta-carotene and vitamin C protect against developing
macular degeneration (AMD).
o AMD is the leading cause of legal blindness in people over 55 in
the United States.
o People with advanced AMD seem to benefit the most from this
treatment.
•
Vitamins E and C can also help to treat uveitis, or inflammation of
the uvea. This is the middle layer of the eye.
o These vitamins can help people with inflammation and help
them to have clearer vision.
Vitamin E and
Photodermatitis
http://www.abc.net.au/news/2011-10-07/uvrays-more-damaging-than-thought/3335828
•
Photodermatitis is a condition where an individual has
an allergic reaction to UV sun rays.
o An 8 day study which compared treatment with
vitamins C and E to a placebo found that people who
took the vitamins became significantly less sensitive
to the sun.
o Another study lasting for 50 days showed a
protective effect from the vitamin C and E treatment.
Vitamin E and Dementia
•
Studies have documented low levels of vitamin E in patients with
Alzheimer's disease.
o A placebo-controlled trial found that supplementation with 2,000 IU of
synthetic alpha-tocopherol daily for two years significantly slowed
progression of Alzheimer's dementia.
•
Vascular dementia (dementia resulting from strokes)
o A study examining risk factors for vascular dementia in elderly
Japanese-American men found that supplemental vitamin E and
vitamin C intake was associated with a significantly decreased risk of
vascular and other types of dementia but not Alzheimer's dementia.
•
Among those without dementia, vitamin E supplement use was associated
with better scores on cognitive tests.
Take Home Points…
 To be able to discuss the importance of Vitamin E in our
diet.
 To understand the digestion, absorption, transportation
and excretion of Vitamin E.
 To be able to identify the major food sources of Vitamin
E.
 To understand the effects of Vitamin E on certain
diseases.
Questions?
http://www.inc.com/tom-searcy/5-great-questions-ceos-ask-customers.html
References
1. National Institute of Health: Office of Dietary Supplements. Vitamin E. Reviewed: June 05, 2013.
Available at http://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/#h2. Accessed
November 06, 2013.
2. Ehrlich S. Vitamin E. University of Maryland Medical Center Complimentary and Alternative
Medicine Guide. http://umm.edu/health/medical/altmed/supplement/vitamin-e Published Jan 15,
2012. Last Updated May 7, 2013. Assessed Nov 10, 2013.
3. Micronutrient Information Center: Vitamin E. Linus Pauling Institute, Oregon State University,
Corvallis, OR. Available at: http://lpi.oregonstate.edu/infocenter/vitamins/vitaminE/. Accessed
November 13, 2013.
4. Bendich A. Vitamin E and immune functions. Basic Life Sci. 1988;49:615-20.
5. Anderson KE. Comparison of fatty acid, cholesterol, vitamin A and E composition, and trans fats in
eggs from brown and white egg strains that were molted or nonmolted. Poult Sci. 2013;92(12):325965.
6. Dietary Facts Sheet: Selenium. National Institutes of Health: Office of Dietary Supplements.
Available at: http://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/. Accessed October 9,
2013.
7. Gropper, SS, Smith. Advanced Nutrition and Human Metabolism, 6th Edition,
Wadsworth/Cengage Learning, 2012.