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Upper Limit Vitamin C and E Intake |
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| Before You Begin Information presented here is for general educational purposes only. Each one of us is biochemically and metabolically different. If you have a specific health concern and wish my personalized nutritional recommendation, write to me by clicking here. |
Contents
Introduction
Vitamin E
Vitamin C
Primer on Free Radicals and Antioxidants
From Hoax to Science
How Much Is Too Much?
When Should I Start Taking Supplements?
The Antioxidant Panel of the Food
and Nutrition Board, Institute of Medicine, National Academy of Sciences (NAS),
announced in 2000 the new recommended dietary allowances (RDA) for Vitamin C
and E. For Vitamin E, the new RDA for both men and women has been raised to
15 mg, up from 8 mg for men and 6.4 mg for women.
The newly established upper level, assuming the source is from supplementation,
is as high as 1,000 mg of Vitamin E (alpha-tocopherol per day). This is equivalent
to roughly 1,500 IU of "d-alpha-tocopherol." For Vitamin C, the new RDA is 90
mg for men and 75 mg for women, up from 65 mg. The newly established upper limit
for Vitamin C is 2,000 mg per day.
Vitamin E
In
view of the mounting evidence that Vitamin E is a powerful antioxidant with
significant health benefits, the NAS panel
virtually doubled their old recommendation to 15 mg of d-alpha-tocopherol (the
natural form of Vitamin E and the basis for the new RDAs) per day for both men
and women.
The old RDA had rated natural Vitamin E as being only 36% more active than the
synthetic form. This report confirms that the difference is much greater. In
fact, the NAS panel has determined that natural
Vitamin E is twice as potent as the synthetic version.
The form of Vitamin E that is best used and
retained by the body is the RRR-tocopherol (alpha). In the process
of making synthetic Vitamin E from petroleum chemicals, fully one half of synthetic
Vitamin E is in the form of tocotrienols, and beta-, gamma- and delta-tocopherol,
all of which the body does not recognize and preferentially excretes. On the
other hand, 100% of natural-source Vitamin E, purified from plant sources, is
in the RRR-tocopherol (alpha) form recognized and used by the body.
Another highlight of the report for Vitamin
E includes the establishment of an upper intake level (UL).
This UL for Vitamin E is 1,000 milligrams daily. This is equivalent to approximately
1,500 international units of natural-source Vitamin E or 1,100 IU of synthetic
Vitamin E. The difference in limits for natural-source and synthetic
forms of Vitamin E underscores the importance of the NAS finding that synthetic
Vitamin E contains compounds with no Vitamin E activity. The UL also establishes
that Vitamin E is safe in amounts much greater (67 times) than even the new
RDAs.
There have been many studies showing the benefits of Vitamin E. The following
two will demonstrate some of them, as well as give you some insight into the
reasons on which the NAS based their decision to increase the RDA and establish
such a high upper limit.
In our first study, which was published in Lancet in 1996, 2002 patients with
angiographically proven coronary atherosclerosis were enrolled in a Vitamin
E supplementation program and followed for a median of 510 days. These patients
were given alpha-tocopherol capsules containing 800 IU a day for the first 546
days and 400 IU daily for the remainder. Results showed that
alpha-tocopherol treatment substantially reduced the rate of non-fatal MI (heart
attacks), with beneficial effects apparent after 1 year of treatment.
In the second study, published in Journal of the American Medical Association
(JAMA), in 1995, 156 men aged 40-59 with previous coronary artery bypass graft
surgery were supplemented with 100 IU of Vitamin E per day and compared to those
men whose intake was less than 100 IU per day. After the treatment,
subjects receiving 100 IU demonstrated less coronary artery lesion progression
than did subjects with intake of less than 100 IU per day, as determined by
angiography.
Studies determining the efficacy between various forms of Vitamin E are less
clear, especially as it relates to alpha- vs. gamma -Tocopherol. Some studies
have suggested that gamma-Tocopherol is more effective, while others show that
a mixed blend of alpha- and gamma- appears to be the best. Until more research
is available, it is clear that the standard form of Tocopherol should be alpha-Tocopherol.
Studies have already determined that Vitamin E derived from natural source ("d"form)
is better than synthetic form ("dl"form).
Vitamin C
The
RDA for Vitamin C
was also increased by the NAS. The new RDA
has been increased by 30% for men to 90 mg per day, and by 16% for women to
75 mg per day. Smokers need an additional 35 mg per day. For the first time,
maximum levels for Vitamin C have also been set. For adults, the upper level
of Vitamin C is 2,000 mg per day.
Dr. Linus Pauling , two times Nobel Laureate and "father of Vitamin C", postulated
the benefits and promoted high intakes of Vitamin C for decades. As early as
the late 1960s, he started taking 2,000-3,000 mg of Vitamin C a day. Dr. Pauling
was way ahead of his times. As the years went by, he increased his Vitamin C
intake progressively until the early 1990s, in the latter years of his life,
when he was taking as much as 18,000 mg a day. He died at the age of 93 and
attributed the last 12 years of his life to his high Vitamin C intake.
To have a better understanding of Dr. Pauling's hypothesis concerning the benefits
of antioxidants, it is helpful to have an understanding of free radicals.
Primer on
Free Radicals and Antioxidants
Molecules are composed of atoms and atoms are composed of a nucleus surrounded
by an orbit of electrons. In a stable molecule, these electrons orbit their
respective nuclei in pairs. When a reaction occurs causing a molecule to
either loose an electron, or gain an extra electron, the result is a molecule
with an unpaired electron. This molecule is called a free radical. It is highly
reactive, meaning it will try to combine with other molecules in order to steal
an electron, so it can return to a stable state. The molecule from which
the original free radical steals the electron becomes a free radical, wanting
to steal an electron, resulting in a domino effect or a self-perpetuating process.
Many of our body's normal metabolic processes produce free radicals. For
example, free radicals are a normal by-product in the production of ATP (the
energy molecule) from glucose. In another case, our body produces free radicals
on an ongoing basis. Certain types white blood cells are able to destroy
invading microbes by the production of free radicals. Free radicals are also
formed by enzymatic production. However, external sources such as pollution,
cigarette smoke and sunlight can also result in the formation of free radicals.
Excessive production free radicals can cause damage. Fats, protein, carbohydrates,
and DNA are all subject to free radical damage. Membranes exposed to free
radicals lose their ability to properly transport nutrients, lipoproteins are
changed into a dangerous form, and damaged DNA has the potential to cause mutations
and cancer. Free radical damage is associated
with almost very disease, including arthritis, heart disease, cataract, cancer,
Alzheimer's, and Parkinson's.
Antioxidants are molecules made by our bodies
to neutralize free radical damage. Antioxidants do this by donating an extra
electron to the free radical without becoming unstabilized itself, also preventing
the otherwise self-perpetuating free-radial process. Although the
antioxidant has donated an electron, thereby becoming a free radical, it has
the property of being much less reactive than the original radical it has quenched.
Being less active, the affected antioxidant does not cause further damage. When
Vitamin E functions as an antioxidant and donates its electrons, it cannot function
again until it has been "recharged", or had its missing electron replaced. This
is where Vitamin C enters the process. Vitamin C donates its electron to Vitamin
E, allowing Vitamin E to function again. Since certain types of antioxidants
work best in different environments - some are effective in the plasma environment
while others work their best within a fatty environment, there is no single
best antioxidant. They all work together. What develops is a complex network
or partnership of antioxidants that not only fight free radicals, but also serve
to regenerate one another. Hence, they work synergistically - that is, when
they are all present, their effect is greater than the sum of their individual
effects.
Fruits and vegetables are very high in antioxidants.
Unfortunately, diet by itself cannot provide the amount of antioxidants needed
for anti-aging purposes. For example, an orange, which is one of the
best sources of Vitamin C, contains about 65 mg of Vitamin C. To get 2,000 mg,
you would need to eat 30 oranges a day. Similarly, to get the 400 IU of Vitamin
E commonly recommended, you would have eat almost 5,000 calories of food, mostly
as fat. Supplementation, therefore, is a cornerstone for good health with respect
to antioxidants. Some common antioxidants available as supplements include:
Vitamin C, Vitamin E, carotenoids, glutathione, bioflavonoids, lipoic acid,
CoEnzyme Q 10, Selenium, and Grape Seed Extract.
From Hoax to Science
The established medical and scientific community accepts new theories only after
vigorous screening and scrutiny, a process that can take years or even decades.
The free radical theory of cellular damage and the recommendation for antioxidants
as a way to overcome it was proposed over 40 years ago. Until the last decade,
it has been tolerated largely as an unsubstantiated theory at best. Medical
schools are so preoccupied with teaching students how to cure disease they do
not spend enough time on disease prevention or alternate forms of treatment.
In essence, we have a whole generation of physicians who are not well versed
on what nutritional supplements can or cannot do. Those who do know and are
well versed in it, practice supplementation.
Doctors who have been prescribing nutritional supplement to patients have been
ridiculed for years. Now they are hailed as pioneers.
How Much Is Too Much?
Many in the forefront of ant-aging research have known for decades that
the RDAs established
since 1941 are outdated, needing revision upwards. The National Academy
of Science's progressive upward
revision of the RDAs in view of mounting evidence in support of antioxidant's
beneficial effect on the body, reflects an admission from main stream research
and medicine that the benefits of nutritional supplementation is real and
not a hoax. The fact that an Upper Level has been established for the first
time as a safe level of daily intake shows that the educated public is demanding
that the scientific community catch up with its own research, as ironic as
that may sound.
There is always a constant battle between the production of free radicals
and the body's attempt to remove these radicals. Data and research continues
to show a role for antioxidants from food as well as dietary supplementation
in disease treatment and prevention. Although optimal
intakes of antioxidants have yet to be determined, and may not be determined
for years to come, science continues to learn more about this fascinating
area each day. With the establishment of upper limits for common antioxidants
like Vitamin C (2,000 mg a day) and Vitamin E (1,500 IU a day), it now is
apparent that the public can safely know that supplementation within these
limits is widely accepted.
| Attention Because of tremendous individual variation, the use of nutritionals should therefore be personalized for your body. One person’s nutrient can be another person’s toxin. If you have a specific health concern and wish my personalized nutritional recommendation, write to me by clicking here. |
When Should I Start Taking Supplements?
Data shows that it takes time for the benefits of the antioxidant effects by supplementation with Vitamin E to become visible. Supplementation is not an overnight process as our bodies have been traumatized by free radicals for many years. Research has repeatedly demonstrated that it takes at least one to two years of continuous Vitamin E intake, for example, to have demonstrable and statistically significant cardiovascular and cancer benefits.
Considering the limited side effects, the risk of not taking natural supplements far outweighs the risk of any potential side effect. To put it another way, the risk benefit ratio favors those who take action now to supplement their diet with nutrients beyond that which can be obtained from diet alone. This is especially critical for those 50 years of age and older, as the accumulated years of damage is greater, and their time is running out.
Research
will never completely satisfy the skeptical mind. Those who take
the time to study the scientific literature that is readily available will
be amazed at the preponderance of data supporting nutritional supplementation
as one of the foundation pillars for optimum
anti-aging health. It is estimated that
over 50% of Americans are taking supplements in one form or another.
Unfortunately, the nutritional supplement industry is laced with unscrupulous
companies pushing products that are unproven or with insufficient research.
The informed mind is the best mind. Do your homework and make an informed
decision before embarking on any nutritional supplementation program of dubious
nature. Focus on supplements that have
an extensive history of research and be careful of products that are supported
by nothing more than testimonials and wild unsubstantiated claims.
| Message from Dr. Lam I hope you have enjoyed reading this article. If you have areas you don’t understand, comments (good or bad), or if you have a specific health concern, feel free to write to me by clicking here. |
About The Author
Michael Lam, M.D., M.P.H., A.B.A.A.M. is a specialist in Preventive and Anti-Aging Medicine. He is currently the Director of Medical Education at the Academy of Anti-Aging Research, U.S.A. He received his Bachelor of Science degree from Oregon State University, and his Doctor of Medicine degree from Loma Linda University School of Medicine, California. He also holds a Masters of Public Health degree and is Board Certification in Anti-aging Medicine by the American Board of Anti-Aging Medicine. Dr. Lam pioneered the formulation of the three clinical phases of aging as well as the concept of diagnosis and treatment of sub-clinical age related degenerative diseases to deter the aging process. Dr. Lam has been published extensively in this field. He is the author of The Five Proven Secrets to Longevity (available on-line). He also serves as editor of the Journal of Anti-Aging Research.
For More Information
For the latest anti-aging related health issues, visit Dr. Lam
at www.LamMD.com. Feel free to email
Dr. Lam at dr@LamMD.com if you have any questions.
Reprint Information
This article may, in its unabridged, unaltered form and in its entirety only,
be reprinted and republished without permission provided that it is for personal
and non commercial education use only and further provided that credit be given
to the author, with copyright notice and www.LamMD.com
clearly displayed as source. Written permission from Dr. Lam is required
for all other use.
©2000 Michael Lam, M.D. All Rights Reserved.
References
Ames BN et al. "Oxidants, Antioxidants, and the Degenerative
Disease of Aging" Proc Natl Acad Sci 1993; 90:7915-7922.
Gaziano, JM et al "Antioxidant Vitamins and Coronary Artery Disease Risk" Am
J Med 1994; 97 ( suppl 3A): 18S-21S.
Hodis, NH, Mack WJ, LaBreeL, Cashin-Hemphill L, Sevanian A, Johnson R, and Azen
SP. JAMA 1995l; 273:1849-1854.
Rimm, EB et al "Vitamin E Consumption and the Risk of Coronary Heart Disease
in Men" N Engl J Med 1993: 328;1450-1456.
Stephens, NG , Parsons A, Schofield, PM, Kelly F, Cheesman, K and Mitchinson,
MJ. Lancet 1996; 357:781-786.
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