Can B Vitamins Lower Risk of Blindness?
Taking a Combination of Vitamins B6, B12, and Folic Acid May Lower Risk of Age-Related Macular Degeneration
By
Jennifer Warner
WebMD Health News
Reviewed By
Louise Chang, MD
Feb. 23, 2009 -- Taking a combination of B vitamins may offer a rare and
inexpensive opportunity to help prevent the most common cause of blindness in
older Americans, age-related macular degeneration (AMD).
A new study shows that women who took vitamins B6 and B12 along with folic
acid had a 34% lower risk of any AMD and a 41% lower risk of AMD with
significant vision loss.
Researchers say treatments for AMD are limited to people in the later stages
of the disease.
"For the large population with early or no AMD, there is no method of
disease prevention other than avoidance of cigarette smoking," write researcher
William Christen, ScD of Harvard Medical School and colleagues in the
Archives of Internal Medicine. "From a public health perspective, this
is particularly important because persons with early AMD are at increased risk
of developing advanced AMD, the leading cause of severe, irreversible vision
loss in older Americans."
Vitamin Combo Curbs Macular Degeneration
In the study, researchers randomly assigned more than 5,000 women over 40
without signs of age-related macular degeneration to take a combination of 2.5
milligrams of folic acid, 50 milligrams of vitamin B6, and one milligram of
vitamin B12 or a placebo every day. The women were part of a trial looking at
the use of these vitamins and cardiovascular disease. The women had heart
disease or at least three risk factors for heart disease at the start of the
study.
During about seven years of follow-up, 137 new cases of age-related macular
degeneration were diagnosed, including 70 that resulted in significant vision
loss.
The results showed that women taking the B vitamin supplements had a 34%
lower risk of any AMD and a 41% lower risk of AMD with vision loss than the
placebo group.
Researchers say the benefits of the vitamin combination in preventing AMD
appeared to emerge about two years after treatment began.
"The trial findings ... are the strongest evidence to date in support of a
possible beneficial effect of folic acid and B vitamin supplements in AMD
prevention," the researchers write. They note that further research is
necessary in other groups of people to confirm their findings.
SOURCES: Christen, W. Archives of Internal Medicine, Feb. 23, 2008; vol 169:
pp 335-341. News release, American Medical Association.
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