Harvard Women's Health Watch

In the journals: B vitamins may protect against macular degeneration

In the journals

B vitamins may protect against macular degeneration

Age-related macular degeneration (AMD) is the main cause of severe and irreversible vision loss in Americans ages 60 and over. About 1.5 million people in the United States have advanced AMD, and another 7.3 million have an early form of the disease that involves little or no vision loss but can progress to the advanced stage. There are some treatments for advanced AMD, but until now the only known way to reliably reduce your risk for developing the disorder has been to stop smoking. (According to the National Eye Institute, some research also suggests a link between obesity and AMD progression.) But a study has found that a daily supplement of folic acid (vitamin B9) and vitamins B6 and B12 reduces the risk of developing AMD in women at high risk for cardiovascular problems.

These findings, published in the Feb. 23, 2009, issue of the Archives of Internal Medicine, come from an ongoing trial at Harvard called the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS). The results stand in sharp contrast to WAFACS findings published in 2008, which showed that the same supplement did not help prevent heart attacks or strokes, even though it lowered blood levels of homocysteine, an amino acid once thought to be linked to cardiovascular disease. Homocysteine has also been implicated in AMD risk.

The study participants were 5,205 women ages 40 or over who did not have AMD at the study's outset but did have three or more cardiovascular risk factors (or a history of cardiovascular disease). The women were divided into two groups at random. One group was assigned to receive a daily supplement containing 2.5 milligrams (mg) folic acid, 50 mg of vitamin B6, and 1 mg of B12 — amounts greater than the recommended daily intake. The other group was given a placebo. The researchers noted new diagnoses of "any form of AMD" and "visually significant AMD," meaning AMD that reduced visual acuity to 20/30 or worse.

To continue reading this article, you must login.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »