By
Jonathan Yoken, MD
Vitamin
and Mineral Supplementation
Patients and
their doctors have often wondered if taking vitamin supplements
could help prevent or minimize the effects of various diseases.
Many small studies have suggested a link between vitamin supplementation
and the prevention of certain eye diseases such as cataracts or
age-related macular degeneration (ARMD). Unfortunately, many of
these studies were not complete enough to answer some important
questions.
Recently,
the National Institute of Health completed a major study to address
this question with regard to ARMD. The Age-Related Eye Disease
Study (AREDS) followed 3,600 patients at 11 centers around the
country over five years with various degrees of ARMD. Overall,
the study found that patients who are at higher risk for advanced
ARMD (loss of central vision), could decrease this chance by about
25% by taking certain anti-oxidant and zinc supplementation. Moreover,
the safety of these supplements was carefully followed. These
vitamins have become known as the "AREDS Formulation".
Who should
take the AREDS Formulation?
Your eye doctor
will be able to tell by examining your retina whether or not you
are at risk for developing advanced ARMD. Your eyes will need
to be dilated in order to make this determination. The AREDS study
found that those patients with little or no evidence of ARMD did
not benefit from take the AREDS Formulation.
What are
the dosages of the vitamins in the AREDS Formulation?
The specific
amounts studied were:
500mg of
Vitamin C
400IU of Vitamin E
15mg of Beta-Carotene (often labeled as 25,000 IU of Vitamin
A)
80mg of Zinc as Zinc Oxide
2mg of Copper as cupric oxide. Copper was added to help
prevent copper deficiency anemia as a result of high zinc intake.
Also, two-thirds
of the study participants took a daily multi-vitamin, such as
Centrum Silver, and this was found to be safe. The AREDS Formulation
is not a substitute for your daily multi-vitamin or other supplements
you may be taking such as calcium or Vitamin D for osteoporosis.
However, do not take additional supplements that are already included
in the AREDS Formulation.
What are
the benefits of taking the AREDS Formulation?
While there
is no "cure" or definitive way to prevent ARMD, the
AREDS Formulation is effective at reducing one's risk of developing
the most severe form of the disease. The supplements decrease
a patient's chance of developing "wet" ARMD by about
25% over a six year period. The Formulation was found to be effective
only in those patients who already had evidence of moderate "dry"
ARMD in one or both eyes, or "wet" ARMD in one eye only.
Those with little or no evidence of ARMD did not benefit from
the Formulation, and therefore these patients should not take
it.
Are there
any side-effects from taking the AREDS Formulation?
Some patients
taking the supplements had minor side-effects including urinary
tract problems secondary to the zinc. Others noted mild yellowing
of the skin secondary to the beta-carotene. Overall, there were
no major side-effects noted.
Is it dangerous
for current or former smokers to take the AREDS Formulation?
Large clinical
trials have demonstrated that beta-carotene increases the risk
of lung cancer in current smokers. Therefore, these patients
should avoid taking the beta-carotene found in the AREDS Formulation.
Most of these patients were heavy smokers. There is no direct
evidence that former smokers are at risk from beta-carotene, but
given that these patients still have a heightened risk of lung
cancer beyond the time they quit smoking, it would be reasonable
for these patients to avoid high dose beta-carotene as well.
There are
AREDS formulations available without beta-carotene.
Where can
I find the AREDS Formulation?
Most drug
stores, Sam's clubs or Costco carry versions of the Formulation.
I generally recommend taking the Ocuvite Preservision AREDS formula
with or without beta-carotene (made by Bausch and Lomb), depending
on the patient's smoking history. The version without beta-carotene
contains Lutein. These supplements come as an easy to swallow
gel-cap that is taken as 1 gel-cap twice a day.
Other anti-oxidants,
such as Bilberry, Lutein, Zeaxanthine, or Omega-Three fatty acids
were not studied by AREDS and there is no definitive information
on their possible benefits or safety.
The National
Institute of Health is currently enrolling patients for a new
trial called AREDS II to study some of these additional supplements.
For more information
visit: www.nei.nih.gov/amd.
