Back to the
Basics: Vitamins Part
2 Vitamin A
We are continuing a series talking about those nutrients
which are Essential to Life. A “Back to the Basics Series”.
Basic questions we need to answer are: Why is this molecule
or element Essential, What Purpose does it Serve, In What
Form is it Best Consumed and How Much do we need. This month
we start our series on the Vitamins that are essential to
life and good health.
Vitamins A
vitamin is an
organic molecule required by a living
organism in minute amounts for proper
health. An organism deprived of all sources of a
particular vitamin will eventually suffer from
disease
symptoms specific to that vitamin.
Vitamins
can be classified as either
water soluble, which means they dissolve
easily in water, or
fat soluble, which means they are
absorbed through the
intestinal tract with the help of
lipids.
In general, an organism must obtain vitamins
or their metabolic precursors from outside
the body, most often from the organism's
diet. Examples of vitamins that the
human body can derive from precursors
include vitamin A, which can be produced
from
beta carotene; niacin from the
amino acid
tryptophan; and vitamin D through
exposure of
skin to
ultraviolet
light.
The term vitamin
does not encompass other
essential nutrients such as
dietary minerals,
essential fatty acids, or
essential amino acids, nor is it used
for the large number of other nutrients that
merely promote health, but are not strictly
essential.
From
Wikipedia, the free encyclopedia
Vitamin A
Essential
Pronunciation: ĕs`sĕn´sjal or
i-
sen-ch
l
a
:basic and fundamental a: being a substance that is
required for normal functioning but cannot be synthesized by
the body and therefore must be included in the diet
s
:absolutely required and not to be used up or sacrificed
s :of the greatest importance s :absolutely
necessary; vitally necessary n :anything
indispensable ie don't leave home without it....More
important than Gummi Bears...
Vitamin
A or Retinol
History
Vitamin A
was the first fat-soluble vitamin to be
discovered. Two independent research teams,
Osborne and Mendel at Yale University and
McCollum and Davis at the University of
Wisconsin, simultaneously discovered it in
1913. Vitamin A comprises a family of
compounds called the retinoids. The retinoid
designation resulted from finding that
vitamin A had the biologic activity of
retinol, which was originally isolated from
the retina.
Why is this Vitamin
Essential?
There are well defined
deficiencies and toxicity of any of the
Vitamins. Our bodies use most of the
Vitamin A we ingest as one of the co factors
which produce molecules, primarily
rhodopsin, which allow us vision,
especially night vision. In general
Carnivores, or hunters have better night
vision than Non-Carnivores. In
evolutionary terms, animals that ate whole
livers, which contain a concentrated amount
of Vitamin A developed and maintain night
vision well whereas grazing animals never
can get enough Vitamin A to develop good
night vision.
Vitamin A is
also essential for immune response;
epithelial cell growth and repair; bone
growth; reproduction; maintenance of the
surface linings of the eyes; and epithelial
integrity of respiratory, urinary, and
intestinal tracts.
Vitamin A Deficiency
(VAD)
The primary worldwide
manifestation of Vitamin A Deficiency is in
children and pregnant women in developing
countries who eat a lot of rice which
contains virtually no Vitamin A.
-
For
children, lack of
vitamin A causes
severe visual
impairment and
blindness, and
significantly
increases the risk
of severe illness,
and even death, from
such common
childhood infections
as diarrhoeal
disease and measles.
-
For
pregnant women in
high-risk areas,
vitamin A deficiency
occurs especially
during the last
trimester when
demand by both the
unborn child and the
mother is highest.
The mother’s
deficiency is
demonstrated by the
high prevalence of
night blindness
during this period.
|
|
The risk
of VAD is increased in patients with fat
malabsorption, cystic fibrosis, sprue,
pancreatic insufficiency, IBD, cholestasis,
and/or small-bowel bypass surgery. It is
also increased in vegans, refugees, recent
immigrants, persons with alcoholism, and
toddlers and preschool children living below
the poverty line. These would be the
most common reasons for VAD in the United
States.
A
few salient facts
from the World Health Organization
- An estimated 250
million preschool children are vitamin A
deficient and it is likely that in
vitamin A deficient areas a substantial
proportion of pregnant women is vitamin
A deficient.
- An estimated 250
000 to 500 000 vitamin A-deficient
children become blind every year, half
of them dying within 12 months of losing
their sight.
What are the best sources
and how much do we need?
| Food |
Serving |
Vitamin A, RAE
|
Vitamin A, IU |
Retinol, mcg |
Retinol, IU |
| Cod
liver oil |
1
teaspoon |
1,350 mcg |
4,500 IU |
1,350 mcg |
4,500
IU |
|
Fortified breakfast cereals |
1
serving |
150-230 mcg |
500-767 IU |
150-230 mcg |
500-767 IU |
| Egg |
1 large |
91 mcg |
303 IU |
89 mcg |
296
IU |
| Butter |
1
tablespoon |
97 mcg |
323 IU |
95 mcg |
317
IU |
| Whole
milk |
1 cup (8
fl ounces) |
68 mcg |
227 IU |
68 mcg |
227
IU |
| 2% fat milk (vitamin
A added) |
1 cup (8 fl ounces) |
134
mcg |
447
IU |
134
mcg |
447 IU |
| Nonfat milk (vitamin
A added) |
1 cup (8 fl ounces) |
149
mcg |
500
IU |
149
mcg |
500 IU |
| Sweet
potato |
1/2 cup,
mashed |
959 mcg |
3,196 IU |
0 |
0 |
| Carrot
(raw) |
1/2 cup,
chopped |
385 mcg |
1,283 IU |
0 |
0 |
|
Cantaloupe |
1/2
medium melon |
466 mcg |
1,555 IU |
0 |
0 |
| Spinach |
1/2 cup,
cooked |
472 mcg |
1,572 IU |
0 |
0 |
| Squash,
butternut |
1/2 cup,
cooked |
572 mcg |
1,906 IU |
0 |
0 |
For most Americans we get
ample Vitamin A from our diet as many of our
foods are fortified with Vitamin A such as
our cereals and some of our milk. Cod
liver oil has always been a good source of
Vitamin A of course as well as Omega 3 fats.
|
Recommended Dietary Allowance (RDA)
for Vitamin A as Preformed Vitamin A
(Retinol) |
| Life Stage |
Age |
Males: mcg/day (IU/day) |
Females: mcg/day (IU/day) |
| Infants |
0-6 months |
400
(1333 IU) |
400
(1333 IU) |
| Infants |
7-12 months |
500
(1667 IU) |
500
(1667 IU) |
| Children |
1-3 years |
300 (1000 IU) |
300
(1000 IU) |
| Children |
4-8 years |
400
(1333 IU) |
400
(1333 IU) |
| Children |
9-13 years |
600
(2000 IU) |
600
(2000 IU) |
| Adolescents |
14-18 years |
900
(3000 IU) |
700
(2333 IU) |
| Adults |
19 years and older |
900
(3000 IU) |
700
(2333 IU) |
| Pregnancy |
18 years and
younger |
- |
750
(2500 IU) |
| Pregnancy |
19-years and older |
- |
770
(2567 IU) |
| Breastfeeding |
18 years and
younger |
- |
1,200
(4000 IU) |
| Breastfeeding |
19-years and older |
- |
1,300
(4333 IU) |
Our bodies can take beta
carotene and convert it to Vitamin A also.
Most multivitamins will have both Vitamin A
and beta carotene in them. The LEF Mix
we recommend has 2500IU of Vitamin A and
2500IU of beta and alpha Carotene which
should be quite adequate taking 7 capsules a
day.
.
International Eye Foundation and Vitamin A
Deficiency
Greenpeace and Vitamin A Deficiency
Global Alliance for Improved Nutrition
The Global
Alliance for Improved Nutrition
(GAIN) was created to fight vitamin and
mineral deficiency. This form of
malnutrition affects more than 2
billion people around the world,
causing birth defects, mental retardation,
learning difficulties, compromised immune
systems, low work capacity, blindness and
death.
Vitamin A Deficiency
Vitamin
A at the Linus Pauling Institute
NUTRIENT DATA LABORATORY
Search the USDA National Nutrient Database
for Standard Reference
The Institute of Medicine in
their Dietary Reference Intake Book and
tables
Next month The Vitamin B's, Vitamin B1
Thiamin
From Dr. Sears' Monthly
Newsletter
The OmegaZone E-Magazine
"For years the medical establishment has been telling
Americans that fighting heart disease means a war against
cholesterol. Slowly but surely, like the powerful Wizard of
Oz façade, the cholesterol story has been slowly eroding.
Now the scientific data is shifting more to inflammation as
the underlying cause of heart disease. Of course, this makes
common sense since the number-one drug to prevent a heart
attack is an aspirin. Although aspirin has no effect on
cholesterol levels, it has a dramatic effect on reducing
inflammation. Recent articles in the New England Journal of
Medicine have again confirmed the importance of inflammation
on heart disease. A crude indictor of inflammation,
C-reactive protein, appears to be more powerful than bad
cholesterol levels in predicting future heart attacks.
But what if there was an even more powerful predictor of
inflammation that could predict heart attacks? As I describe
in my newest book, “The Anti-Inflammation Zone,” such a
blood marker exists. It is the ratio of arachidonic acid
(AA) to eicosapentaenoic acid (EPA). This marker of
inflammation precedes C-reactive protein by years. You could
take drugs, such as statins, on a lifetime basis to reduce
C-reactive protein. Of course, there are some side
effects, such as memory loss, muscle weakness, neuropathy,
and liver damage. But statins don’t reduce the AA/EPA ratio
– they actually increase it. On the other hand, taking
high-dose fish oil reduces the AA/EPA ratio, and the only
known side-effect is to make you smarter. The amount of fish
oil you need to reduce inflammation depends on how well you
control insulin in your diet. The more you control insulin
by following the Zone Diet, the less fish oil you need. On
the other hand, the less you control insulin, the more fish
oil you need. The choice is yours. Whatever approach (drugs
or diet) you choose, just keep in mind that controlling
inflammation is a much wiser medical approach to reducing
heart attacks than controlling cholesterol."
Let us know if you want the
AA/EPA test. The Cost is $300 and includes a consult
with Dr. Christian to discuss the results. We also
talk about the AA/EPA test in detail in our Omega Zone
Seminar.
Visit Dr.
Sears Web Site.. Join the Forums and Sign up for his
Newsletter.
Misty Bashara Personal Trainer and Massage Therapist
Misty Bashara is well known in San Antonio
for her contributions to physical fitness and health. She
has personally trained many and is owner of San Antonio
Professional Fitness.
Misty Bashara CFT, AMTA, NCBTMB is the owner of
Professional
Fitness by Misty in San Antonio, Texas. Misty has over
25 years experience in the Fitness Industry and has been a
Fitness Trainer for 21 of those years. Misty holds
certifications as an Advanced Fitness Specialist as well as
the Elite Certification from the Cooper Clinic Center for
Aerobic Research. In addition, Misty has been a Nationally
Certified Massage Therapist for almost 18 years. She holds
the prestigious gold standard for bodyworkers, the National
Certification Board for Therapeutic Massage Therapy and
Bodywork (NCBTMB) credential. She is also certified through
the American Massage Therapy Association (AMTA) and the
Texas Department of Health. Misty received her Yoga Teacher
Training through the Living Yoga Program qualifying as a
Yoga Alliance Yoga Instructor. Misty has the knowledge and
experience to tweak anyone's fitness program giving them an
edge in the hurried world in which we live. Misty is a
Master Trainer who works with individuals who are CEO's,
individuals in management, housewives, secretaries,
overweight, underweight, and unfit; anyone who is
interested in improving their overall fitness and health.
Misty is currently helping top notch professionals from San
Antonio Corporations such as SBC, H.E.B., and others to
maintain their edge.
Benefits of
Massage
Check Out our New Massage Menu...
The benefits of massage are
Occur Via Several Mechanisms:
Biomechanical
Mechanisms: Massage
can produce mechanical pressure, which is expected to
increase muscle compliance resulting in increased range of
joint motion, decreased passive stiffness and decreased
active stiffness . Mechanical pressure might help to
increase blood flow by increasing the arteriolar pressure,
as well as increasing muscle temperature from rubbing
and thus reducing the
severity of muscle soreness.
Neurological
Mechanisms: Mechanical pressure
on the muscle is expected to increase or decrease neural
excitability and muscle spasms as measured by the Hoffman
reflex. The Hoffman reflex is brought about by stimulating a
nerve, particularly the tibial nerve, with an electric shock
and is essentially measuring deep tendon reflexes and the
level of spasm a muscle has.
Physiological Mechanisms:
Changes in parasympathetic activity
(as measured by reduced heart rate and blood pressure
and improved heart rate variability) and dangerous hormonal
levels (as measured by Cortisol levels) following massage.
The immune system may be improved by increasing White
Blood Cells and Natural Killer Cells.
Psychological
Mechanisms: A reduction in
anxiety and an improvement in mood state also cause
relaxation after massage.
MASSAGE THERAPY GROWS IN POPULARITY Fact Sheet
2005 Massage Therapy Consumer Fact Sheet .pdf file
Contraindications of Massage
Seek
medical advice before having a massage if you suffer from
phlebitis, thrombosis, varicose veins, severe acute back
pain, or fever.
Swellings, fractures, skin infections, or
bruises should not be massaged. Lumps and swellings should
be checked by your doctor.
Massage of the abdomen, legs, and feet should
not be given during the first three months of pregnancy.
Cancer patients are best treated by specially
trained practitioners who know which areas to avoid and
which kind of massage is appropriate.
The cultural and philosophical aspects of pressure, massage,
and touch healing as alternative therapies.
Oumeish OY Skinmed.
2005 Mar-Apr;4(2):93-100.
The mechanisms of massage and effects on performance, muscle
recovery and injury prevention.
Related Articles,
Links
Weerapong P,
Sports Med. 2005;35(3):235-56.
Misty
Bashara, Personal Trainer and Massage Therapist
Contact
Misty
Bashara
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