Vitamin B and folic acid may reduce risk of age-related vision loss

Harvard Medical School (HMS) researchers at Brigham and Women’s Hospital have found that taking a combination of vitamins B6 and B12 and folic acid appears to decrease the risk of age-related macular degeneration (AMD) in women. This research is published today’s issue of Archives of Internal Medicine.

“Women taking the supplements had a 34 percent lower risk of any AMD and a 41 percent lower risk of visually significant AMD,” said William G. Christen, an HMS associate professor of medicine at Brigham and Women’s. “The beneficial effects began approximately two years after the start of treatment and lasted throughout the trial.”

Christen and colleagues conducted a randomized, double-blind clinical trial involving 5,442 women ages 40 and older who already had heart disease or at least three risk factors for the disease. Of these, 5,205 did not have AMD at the beginning of the study. In April 1998, these women were randomly assigned to take a placebo or a combination of folic acid, vitamin B6, and vitamin B12. Participants continued the therapy through July 2005 and were tracked for the development of AMD through November 2005.

Over an average of 7.3 years of treatment and follow-up, 137 new cases of AMD were documented, including 70 cases that significantly affected vision. Of these, 55 AMD cases, 26 visually significant, occurred in the 2,607 women in the active treatment group, whereas 82 of the 2,598 women in the placebo group developed AMD, 44 cases of which were visually significant.

“These findings apply to the early stages of disease development and may be the first identified way — other than not smoking — to reduce the risk of AMD in individuals at an average risk,” Christen said.  “From a public health perspective, this is particularly important because persons with early AMD are at increased risk of developing advanced AMD, which is the leading cause of severe, irreversible vision loss in older Americans.”

The study was supported by grants from the National Heart, Lung and Blood Institute and from the National Eye Institute.